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Data Storage Hardware

Mirroring Controllers - What have been Your Experiences? 367

Today's installment is a lengthy (but hopefully informative) piece on mirroring controllers. Ever had weird problems with a FastTrack TX2000? Are you curious how well HighPoints RocketRAID boards are really supported? Ever wondered which controller gives you the best performance for every dollar spent? In true Slashdot tradition, we're taking the issue and throwing it out to you, the readers. Futurepower(R) is willing to start us off with a wealth of information on his experiences, and I'm hoping a few of you are willing to do the same.
Futurepower(R) asks: "What experiences, both good and bad, have you had with mirroring controllers? Are there manufacturers I haven't found?

For those who are interested but don't have experience, mirroring controllers (RAID 1) provide several advantages:
  1. They prevent data loss when a hard drive fails. The other drive in the mirror takes over seamlessly.
  2. Reading of data is considerably faster since the controller reads the data from the drive that has a head closest to the data.
  3. You always have a full hard disk backup that you can pull from your system at any time, such as before installing new software.
  4. You can clone a Windows XP drive using the RAID card, and you will have a bootable copy. This is valuable, since the Windows XP file system cannot copy all of its own files. (Don't flame this; it has been verified many times by Microsoft employees, who often suggest using the third-party tools.)
I've found four manufacturers that make inexpensive mirroring controllers:
  1. Promise Technology's FastTrak TX2000 is available for about $85 delivered.
  2. HighPoint's RocketRAID 133 costs about $80.
  3. ACARD Technology's AEC-6880 costs about about $85. Froogle found only one vendor. That's scary.
  4. Adaptec makes the ATA RAID 1200A, which is available for about $59 before delivery charges.
As you can see, these controllers cost from $59 to $85. Last weekend Fry's was selling a retail boxed 1800 MHz Athlon XP processor with fan included and an ECS motherboard for $59 total. So $80 seems like a lot for a little card with one chip and a flash ROM.

ECS (EliteGroup) has made 11 motherboards with on-board RAID mirroring controllers. One of them, the P4VXAD, has a Promise controller and costs about $52. What's that about? Employees at Fry's tell me that ECS has the poorest quality control of any of the motherboard manufacturers that they sell. To me, ECS motherboards seem to have surprisingly high quality. However, we have only tested three, and only one extensively.

Silicon Image makes, or made, their 0680 RAID chipset, and Koutech Systems sells the IOFLEX-Pir133 using that chipset. It costs $25 retail. I tried a Koutech card and had a lot of trouble with it, even after updating the BIOS. I talked to an application engineer at Silicon Image and a manager there. I was told that SI bought the technology from another company, and apparently it is no longer supported, doesn't work well, and the company does not intend to put more money into it. I found that the Koutech card corrupts files. The card gives a Stop 07B error when going into the Windows XP Recovery Console, unless the driver is loaded by hand, every time. I lost a lot of time with a product that apparently should not be sold.

My experience with mirroring controllers is mostly with those from Promise Technology. I've been using Promise mirroring controllers since they began making them.

The good about Promise:
  1. Promise has been selling RAID 1 controllers a long time. They work.
  2. Promise controllers can clone a hard drive quickly.
  3. Now some motherboards have Promise mirroring chipsets. You can get the entire motherboard with the Promise controller on the board, for maybe $50 more than the Promise controller card alone.
  4. Linux drivers are available. The web site says, "Windows XP/2000/NT4/Me/9x; Novell NetWare 4.1x/5.x; RedHat Linux 7.0/7.1/7.2; TurboLinux Server 6.5; TurboLinux Workstation 7; SuSE Linux 7.2; OpenLinux 3.1" Does that mean that later versions of Linux can't use this card, or did Promise forget to update the brochure PDF file?
  5. Promise controllers work fine under DOS, but there is no error reporting if for some reason the mirror breaks.
The disadvantages with Promise, in my opinion:
  1. Promise mirroring controllers have a software feature called "sychronization". I've asked many times over the years why it is necessary, since mirrored hard drives should be synchronized 100% of the time. I've never gotten an answer. Recently I've been told by Promise technical support people not to use synchronization, since it has caused problems. It sounds like some technical problem is being hidden.
  2. Promise does not support their oldest mirroring controllers under Windows XP. This is a problem since there are many business computers that are used for data entry. A Pentium II is as fast as is necessary. Windows 98 is stable with only one program running. Now those computers need to be converted to Windows XP, since Microsoft has declared that its operating systems have a curious quality: They die. (According to Microsoft, it doesn't matter that at least 100,000,000 people are using Windows 98 worldwide, it came to the end of its life on "30-Jun-2003".)

    So, it is necessary to buy another controller for old data entry systems. Notice that Microsoft and Promise could decide to play this game again, and I would like to avoid the second round of buying and installing even another controller. I'd like to find a company that continues to support its products.

    The speed of computers used for data entry does not matter, but the security of the data does. Hard drive failures are becoming rare, but a hard drive failure can cause a lot of problems on a data entry computer, so mirroring is required.
  3. Some Promise controllers, especially those on motherboards, take a long time to boot. Dots crawl across the screen even if no drives are connected to the controller. Is keeping the Promise name on the screen a time-wasting sales message from Promise? Recently Promise released a BIOS upgrade for some of its cards that reduced the dot-crawling time. However, there is apparently no upgrade for Promise controllers on motherboards.
  4. About 2 months after I reported problems, Executive Software said they found a bug in their Diskeeper defragmentation software that might cause data corruption when used with Promise controllers. They said everyone using Diskeeper should upgrade to the new, free, minor version. I've seen no problems since then.
  5. Promise Technology's sales literature can be disgusting. This is the second sentence in Promise's description of the FastTrak TX2000: "The FastTrak TX2000 ATA RAID card supports Ultra ATA/133 drives to rock workstations and boost small (or large) office servers like never before." To me, this is obviously written by someone who knows nothing about the product and doesn't care.
  6. I find the abundant use of PDF files and unnecessary JavaScript on Promise Technology's web site annoying.
The Adaptec controller is cheaper, but it is Windows only. There are apparently no Linux drivers. This is a huge drawback, since these same old data entry computers may be still running when Windows dies again, and Windows XP is no longer supported, and there are Linux versions of the data entry programs, or they run under Wine.

The Acard controller supports SuSE, Red Hat, Caldera, and Turbo Linux, it says. But remember, Froogle found only one vendor.

HighPoint says they support Linux: "Linux Red Hat 7.3 & 8.0 (Software RAID Only)". This apparently means the card does not support Linux at all, since Linux has software RAID built in.

So, that's the extent of my knowledge and experience. Can you provide further insight?"
This discussion has been archived. No new comments can be posted.

Mirroring Controllers - What have been Your Experiences?

Comments Filter:
  • by Anonymous Coward on Thursday August 28, 2003 @05:45PM (#6819288)
    I just want to say that it's absolutely impossible to read that much italic. My eyes are bleeding.
  • 3ware (Score:5, Informative)

    by killmenow ( 184444 ) on Thursday August 28, 2003 @05:48PM (#6819319)
    look [3ware.com]

    That's all I'm sayin...
    • Re:3ware (Score:5, Informative)

      by mukund ( 163654 ) on Thursday August 28, 2003 @05:59PM (#6819415) Homepage
      I work at a longtime Linux server vendor in UK. We have many many man-years of driver and performance related experience with Linux and storage hardware. I can attest to the fact that 3ware make some of the best trouble-free well-supported ATA RAID controllers for use under Linux. (Please take this as a personal opinion -- do your own research before you buy and use these controllers.)
    • Re:3ware (Score:2, Interesting)

      by owlstead ( 636356 )
      They may be great products, but they are a bit expensive for home use.

      The prices can be a bit difficult to find using the site, but all serial ATA raid controllers were above 400 US dollars.

      I've heard of these controllers before, and people seem to like them very much. But at this price-point (and maybe availability too) they seem to be aimed more at the professional market.

      Which is fine if you are a professional user, obviously.

      Warper
    • Re:3ware (Score:3, Informative)

      by RedDirt ( 3122 ) *
      Absolutely. I have a 6000 series card (2 port) and one of their new low-profile 8506 SATA cards. Leave the consumer grade junk behind and get a well supported product. Linux works flawlessly on them and the Windows support is pretty decent also (they still make NT4 drivers available for the 6000 card).

      I tried out an Adaptec 1210SA raid controller since the box claimed Linux compatability. Bull. They support a handful of distros and and even smaller number of patchlevels of kernels with their set of bi
    • Re:3ware (Score:3, Insightful)

      by yem ( 170316 )
      Its true. Promise and Adaptec offerings are extremely disappointing. Binary drivers. Limited distro support and poor performance.

      The 3ware series OTOH are excellent. Good support - no download required. Web admin and monitoring available. ++

    • Re:3ware (Score:3, Informative)

      by Anonymous Coward
      We have 3 Linux SMP servers each running a 4-disk Raid 10 (mirroring and striping) 3ware RAID array. We had started with Mylex controllers and SCSI RAID. 3ware has proven to be far less expensive, significantly faster, and more reliable (less drive failures %age wise; none of the arrays, SCSI or 3ware IDE, have ever lost data).

      3ware drivers have been integrated into the Linux kernel for some time. Promise, Highpoint, etc. has binary drivers that limit your kernel options.

      3ware has on-board logic to han
    • Hm, those cards look nice, especially the SATA variant.

      I've been using software-RAID for some time, and I'm quite pleased with it. However, I'm considering a switch to hw RAID next time I'm upgrading my machine. A few questions:

      1. If I connect two IDE drives on one cable to a HW RAID card, can the failure of one the disks make the other disk unavailable, and thus corrupt the entire disk set? (Since they both operate via the same cable.) This is a major angst point for me, so if someone could clear this up
      • You can't attach two drives to one SATA cable; problem solved.
      • Re:3ware (Score:3, Informative)

        by onyxruby ( 118189 )
        Your question about multiple drives per channel is for IDE controllers. This could be a potential concern, and many IDE RAID cards have one channel per drive, that they support. For example, look at this SX6000 [promise.com] from Promise. If you do have a RAID card fail, you'll have to replace it with an identical card. It's pretty rare, but it certainly can happen.

        Your also asking about adding a drive to a RAID array. Some drive arrays will allow this, but generally speaking it won't. If you want to add a drive to an

      • Re:3ware (Score:3, Informative)

        by zsazsa ( 141679 )
        If I connect two IDE drives on one cable to a HW RAID card, can the failure of one the disks make the other disk unavailable, and thus corrupt the entire disk set?

        Yes. Which is why 3ware doesn't let you do that. One drive per channel is the rule. The boards even come with single-drive ribbon cables.
      • Re:3ware (Score:3, Informative)

        by zsazsa ( 141679 )
        Or can I take two RAID-1 disks used on a 3ware RAID card and just plug them into a Promise RAID card, and still be able to access the disks? Or is this something that requires a reformat/repartioning or similar?

        (Apologies for responding in two separate posts)

        In my experience, you can plug one half of a 3ware RAID-1 mirrored set into a standard IDE controller and read the data just fine. Accessing any other levels, such as 0 or 5, would be a crapshoot on anything but another 3ware.
      • Re:3ware (Score:3, Informative)

        by AlecC ( 512609 )
        2. Are the various HW RAID solutions compatible with each other? My nightmare is buying a card or a motherboard with a built-in RAID, and if I then experience a hardware error in the card or mb, I must replace the faulty card/mb with more or less exactly the same type? (This will probably occur three months after the hw goes out of production)

        In my experience, no. The Mylex raids we used "borrowed" a small amount of disk at the start of the drive for its own purposes. I would think it very unlikely that t
    • Escalade 7500-4 (Score:3, Informative)

      Ive been using this card 24-7 in an dual Athlon system since December and its been great. I chose to do RAID 10 with 4 drives. Rebuilds do kinda suck, but the 3ware desktop manager allows you to adjust the parameters to make general use acceptable. Probably wouldnt want to spool any video while its doing this, but everything else is ok. I believe I paid about $300 then, newegg has for $275. It also does raid 5. Keep in mind they have a newer version out said to be faster. In anyevent, anybody consider
  • missing option (Score:5, Informative)

    by Tumbleweed ( 3706 ) on Thursday August 28, 2003 @05:49PM (#6819323)
    Can you spell 3ware [3ware.com]?
    They do more than just mirroring, and aren't cheap, but if you wants the quality, you gots ta pay the piper.

    Drivers are in the Linux kernel, and have been for some time. ATA or S-ATA versions available.
    • 3Ware (Score:5, Interesting)

      by Rob Riggs ( 6418 ) on Thursday August 28, 2003 @06:20PM (#6819572) Homepage Journal
      I second (third?, 20th?) this sentiment. I've owned a 8500-4 for about a year now with drives in a mirrored configuration. This is for a home system and has suffered numerous power outages and kernel-development related crashes (alpha release drivers and such) and I have never had a problem with recovering the data.

      On the other end of the spectrum, however, is OS-level mirroring. I have only experience with Linux RAID-1, both that has never failed me either. I have run software RAID-1 for many years and have only (long ago) had problems where I had to "raidhotadd" a drive from a mirror set that was no longer recognized.

      My recommendation, based on both performance and ease of use, is to use a 3ware controller. That coupled with Linux LVM makes disk management and resiliency a breeze.

      My only disappointment with the 3ware controller is that one cannot make take a single disk with data on it, add a second disk and tell the controller to mirror the first disk to the second. With the 3ware, you will lose the data on both disks when making a mirror. (So says 3ware tech support.)


      • 3Ware controllers are expensive, I note. The cheapest: About $130.

        You said, "My only disappointment with the 3ware controller is that one cannot make take a single disk with data on it, add a second disk and tell the controller to mirror the first disk to the second. With the 3ware, you will lose the data on both disks when making a mirror. (So says 3ware tech support.)"

        That's a BIG disappointment. The on-board ECS Promise controllers, as well as the adapter cards have that.
        • by bbk ( 33798 ) on Thursday August 28, 2003 @06:48PM (#6819777) Homepage
          I think this is due to the way 3ware formats the disks for use in an array. You can't just pull a disk out of an array (even if it was in JBOD or RAID1 mode0), slap it on any old spare drive controller, and read the data - the format is specific to a 3ware controller.

          That said, any 3ware controller can read a disk that was written to by another controller (the format hasn't changed), provided the physical interface is the same. I've used drives from a 6400 on a 7500 without any trouble.

          The benefits of the special format basically amount to being able to identify what part of the array a drive is from, and it's function, while swapping them around. You can plug disk 3 into disk 2's connector, and the card will identify and deal with the situation appropriately. Pretty useful in a larger array, or if you use the same hotswap cartridges on multiple systems, and get them mixed up.
  • by Wintermancer ( 134128 ) on Thursday August 28, 2003 @05:52PM (#6819348)
    My thoughts on the Promise FasTrack controllers:

    We use 'em at work. On the Windows 2000 side, they come with decent management software and for the most part, are relatively reliable.

    However, they are far from perfect. I've had several W2K servers blue screen when doing a hot-swap. Joy.

    The FreeBSD drivers are bloody stable as hell. No complaints.

    The Linux drivers provided by Promise are, IMHO, a POS. Pain to compile. No management software. Diagnositics are limited. As a result, I'd go with a different IDE controller card if you want it for Linux. YMMV.
    • by flonker ( 526111 ) on Thursday August 28, 2003 @06:44PM (#6819751)
      We originally used Windows NT 4.0 software mirrors, but that had too many flaws. Mirrors would sometimes break with no notice, and one mirror would end up being months out of date when something did come up. And frequently, we would have flaws with the boot process. Only one of the drives gets a real boot image, or something along those lines. I'm not quite sure what happened, someone else eventually figured it out and fixed it. But we were booting off of floppies for months on a couple servers.

      Eventually, we started using Promise and Adaptec RAID controllers. Both have been wonderful. They both gave good warnings when one of the drives failed. We only had one problem in several years. One of the Promise controllers died of heat exhaustion, but that was the time the power supply fan went.
  • 3ware (Score:4, Insightful)

    by compwizrd ( 166184 ) on Thursday August 28, 2003 @05:54PM (#6819362)
    Why no mention of the 3ware 7000-2?

    Easily beats most if not all of these cards, especially since it is a hardware card, unlike some of those software cards mentioned.
  • Promise FastTrak (Score:4, Informative)

    by mnelson ( 17017 ) on Thursday August 28, 2003 @05:55PM (#6819378)
    I have used several Promise FastTrak RAID controllers and have had varied results, but all in the "crappy" range. Their drivers are proprietary, so you have to stick with the pre-compiled kernel module. This means you also have to stick with a pre-compiled distro kernel so the symbols match. Promise has always been several kernel versions behind, so if there is a kernel security upgrade, you have two choices: 1. patch the kernel and break the Promise card or 2. Leave a vulnerable computer up and running. You can generally force a promise module into a non-matching kernel, but I've always been hesitant to do that.

    I have switched every Promise installation to 3ware cards because of this. They are open source drivers, very current, and perform well. Their tools run as a web daemon under Linux so you can check status/reconfig on the fly. Really amazing Linux support, and a reasonable price... (and no, I'm not affiliated...:) )
    • I've configured 2 servers with Promise cards. They have a "partial open source" module which you can compile to fit your kernel. Worked fine for everyting between 2.4.18-2.4.22

      So far, I've found that using the open-source module works just fine.... my only beef being that you have to compile SCSI support (as a module) into the kernel in order for it to load properly. Ah well.
    • Re:Promise FastTrak (Score:5, Informative)

      by gujo-odori ( 473191 ) on Thursday August 28, 2003 @07:44PM (#6820188)
      Promise cards are directly supported by the kernel, though, so you don't have to use Promise's crappy drivers.

      I'm writing this on a Debian Sid system with a 2.4.20 kernel, that I installed to RAID 1 on a Promise 20265 (onboard chip). To get the support into your kernel, you need:

      CONFIG_EXPERIMENTAL=y

      from code maturity options, and:

      CONFIG_BLK_DEV_ATARAID=y
      CONFIG_BLK_DEV_ATARAID _PDC=y

      from IDE chipset support/bugfixes.

      If you have a Highpoint or SII, use:

      CONFIG_BLK_DEV_ATARAID_HPT=y
      CONFIG_BLK_DEV_ATA RAID_SII is not set

      Note that the following should not be set. If they are, you will not get the ATARAID functionality, and the Promise will be seen as just an ordinary IDE controller:

      CONFIG_BLK_DEV_PDC202XX_OLD
      CONFIG_BLK_DEV_PDC2 02XX_NEW

      A Debian install CD that supports Promise chips in RAID mode is out there, it's what I used to install this system. I don't remember where I got it, but Google can help. The kernel is 2.4.20, and it also supports Reiser and devfs.

  • mylex (Score:3, Informative)

    by skt ( 248449 ) on Thursday August 28, 2003 @05:55PM (#6819380)
    Mylex controllers work very well for higher end SCSI workstations and servers. I've used these in a few systems and they are very easy to setup in both linux and windows, offer great performance, and well supported. A little on the expensive side though..
    • I have to disagree, I've used a great number of these, and have experience at a hardware vendor who sold these things for years and I have to say they are a poor choice.

      Outrageous failures, configuration hassles, expense, go with the 3ware...

      Chris

  • Don't forget heat (Score:2, Interesting)

    by stacko ( 673397 )

    I've used the Adaptec card before, and I learned the hard way that you need to be aware of heat. Two modern high-speed IDE drives generate a large amount of heat, and if you mount the two directly next to one another in the case you may well burn one out, as I did.

    The dead drive may have had some other defect, but I doubt it as the thermal alarm on the MB would sound after a few hours of usage. Even after replacing the drive (and being sure the two drives were mounted far enough apart to allow airflow

  • by gl4ss ( 559668 ) on Thursday August 28, 2003 @05:56PM (#6819384) Homepage Journal
    usually (afaik/iirc/if_i_got_a_clue) the cards that are cheap use the cpu on motherboard for the raid functionality, and as far as i'm concerned i find their 'only' use to be cheap(ish) way to add more ata drives to a system.

    get a real card or you might just as well use software raid, the good models don't come with 64mb of mem just for kicks either, and the good models have linux support too (adaptec 2400a, if that was the model i installed once, i think it is, even came with managing software that was a bootable linux cd). sure it's expensive but it's REAL, not just an ata interface and programs.

  • by hopews ( 450546 ) on Thursday August 28, 2003 @05:57PM (#6819395)

    The purpose of a raid card is improved reliability. Thus, you shouldn't try to cut corners on quality control to save a few bucks. After all, you're already springing for two drives.

    I have had very pleasant experiences with 3ware [3ware.com] controllers, both under linux and Win32. Currently I have a 6400 running under Suse 7.3, and three 7400s running under RedHat 8. With some hotswap drive bays, you can even unplug a drive with the system running.

    They might cost a little more, but they're widely used under more grueling conditions than the more dirt cheap designs. Also, if you're simply doing raid 1, you can use one of their previous generation cards with no performance penalty, and save a bunch of bucks.

  • Note that all of the controllers listed have one common quality.

    They are a garden-variety IDE controller with some extra BIOS and driver code. They are charging you extra because you are willing to pay a premium for it.

    Unfortunately, Windows XP and Windows 2000 workstation both ship with the mirroring code disabled, which is unfortunate.

    Having said that, there's very little benefit in worying about if the extra BIOS and driver code is going to work under Linux. As long as the chip lets you get to the d
    • Unfortunately, Windows XP and Windows 2000 workstation both ship with the mirroring code disabled, which is unfortunate.

      Huh? I'm curious to know what you're talking about, since dynamic disks are enabled on Win2k Pro/Server and XP Pro. You can then setup a mirrored array with those dynamic disks. It's all in the help file. Try right-clicking on "My Computer" and choosing "Manage Computer". Then go to the "Disk Management" section.
      • No, I do know what I'm talking about. Try it on your machine, if you are so inclined.

        NT Workstation, 2k Pro, and XP Pro all support dynamic disks but *not* fault tolerance (defined as RAID 1 or RAID 5). They do support RAID 0, however.

        The disk management interface *can* create a fault tollerant set from a workstation OS on a remote machine running NT server, 2K server, etc. That's why it's in the help file.

        You can hack the dynamic disk stuff to make it think it's running a server OS (same executable i
  • aside from read performance, you use RAID 1 for high availability (reduce MTBF, eliminate MTTR from the equation). but already, RAID 5 gives you more h.a.

    In addition, it seems like disks are no longer the weakest link in the MTBF chain - assuming redundant PSUs, your main concern is really your CPU/RAM/bus/chipset. To improve this situation, you need n+1 redundancy, and that in most cases means a specialized piece of hardware (h.a. NAS) or a SAN that can be failed over.

    If you like that minty-fresh open so
  • by timmyd ( 108567 )
    I use a low-end 3ware raid controller doing raid1 (the 7000-2 product). It has worked great so far under linux for me.
    http://www.3ware.com/products/parallel_ata.as p

    I believe it's hardware based, so it will cost a little more than a cheaper software based card(like twice as much-- around $120). I don't have the experience with a drive failing, but setting it up was painless. All you have to do is like press a key during boottime and it's like partitioning a harddrive, but easier.
  • I recommend 3ware (Score:3, Informative)

    by FattMattP ( 86246 ) on Thursday August 28, 2003 @06:01PM (#6819428) Homepage
    I use 3ware [3ware.com] cards and like them. The drivers are GPL unlike the Promise controllers which, if I recall correctly, are binary only.
  • IDE mirrors are theoretically wonderful, but don't base your entire recovery plan on them. Here's the story from about a month ago... Small webserver running on a Soyo DRAGON plus MB (Promise IDE Mirror built in), 1700XP CPU, 2 60GB in RAID1, Gentoo, etc. I set the system up in January of '02, and it took a digger this past July. Down hard, with a HD failure. When I went to check the contents of the hard drives, I discovered that one was toast (physically defective), and the other had a fully functional im
  • I have an SX4000, and my main problem with it is that they don't keep up on Linux support. They only recently released Redhat 8/9 drivers. For the longest time I've been forced to use Redhat 7.3 in order to use the hardware RAID capabilities. Granted, they did actually release the drivers, but back in January (when I got the card), Redhat 8 had been out for some time. When Redhat comes out with a 2.6 kernel version, I'm willing to bet you'll be waiting a year before you can upgrade. But on the upswing,
  • by Jerk City Troll ( 661616 ) on Thursday August 28, 2003 @06:01PM (#6819437) Homepage

    Specifically, the RocketRaid 133 [highpoint-tech.com] (based on the HPT372A chipset). The card runs quite well under Linux. The Linux driver [highpoint-tech.com] from HighPoint is quite good (sadly, only partially open source) and provides a /proc interface. (Don't worry, it compiles just fine in any kernel.) Sadly, I cannot show you output from the interface because Slashdot refuses to let me post it (citing junk characters). Stupid Taco. The interface also allows you to issue commands to the controller without rebooting, but documentation is poor. The BIOS utility is also quite good.

    Anyway, the device hosts two RAID-1 arrays, one with 2 80Gb Seagates (ST380021A) and the other with 2 200Gb Maxtors (6Y200P0). They appear as SCSI devices. I have tested the mirroring and I am mostly satisfied.

    Basically, I simulated a failure on one disk (removing it then performing some work on the other). When I reattached the drive, the card recognized the "failure" immediately and wanted to build the array. For my first test, I let the BIOS do exactly that. Took a very long time, but the mirror was recreated successfully and there were no problems (I tested by removing the first disk and trying again--the mirror was good). The second test was letting the driver do it after the machine had booted. This was a dismal failure. The card does NOT like rebuilding the mirror once the system is running.

    Performance is quite good. Even though this is not HighPoint's latest offering, I am still quite impressed. I don't have any hard benchmarks, but I can post some later if you'd like.

    These two arrays are accessed by many machines in my home network over NFS and by on average 5 users logged in remotely. They serve games, web pages, and my software, movie, and music archive. These arrays take a decent amount of stress, but nothing severe.

    I'll post more in this thread if I think of anything. I'll answer any questions about the card's performance if you have any.

  • This is the perfect Ask Slashdot for me, since I have been wondering about this for some time.

    With RAID-5, you can lose one drive and still retain your data. However, there's always that chance that you'll lose a second drive before your spare gets completely rebuilt. In that case, there's no way to recover your data. (Correct me if I'm wrong.)

    Let's say, then, that I want to make a RAID-1 mirror of two RAID-5's. Two racks of drives, each rack in RAID-5 configuration, and I want to mirror those racks

    • If you are in the sort of situation where you are physically unable to replace a drive between time-of-failure for the first drive, and time-of-failure for the second drive, then a mirrored RAID5 configuration won't do you a lick of good, because your laziness/inability to get into the hosting center will just cascade onto any hardware setup you can think up.

      Instead, consider going with fully managed SAN storage. Yes, it's immensely expensive, but then again you never need to worry about hardware failure

      • 5 + 1 is silly. The problem with 5 + 1 as it only allows 2 drives to fail but makes half your drives useless. On the other hand raid 5 + 0 allows the same 2 drives to fail but gives your the performance of two striped RAID 5 arrays. However, if you have 4 drives and dont have the money for a RAID 5 controller w/ CPU. you can do RAID 10 in software for cheap. However, you get N/2 space instead of N-1
    • You could do it with external RAID-5 arrays that present themselves as a single SCSI disk and then use a SCSI RAID controller to mirror them.
  • This is a huge topic, and I've only ever looked into part of it in depth, but:

    Remember that for most motherboards, their RAID implementations are going to be software based, and not hardware. This makes for a cheaper chipset in general, and since the CPU speed is fairly high now the performance hit you experience is pretty nominal compared to the performance of a hardware based controller. The only REAL exception to this is for RAID 5 controllers - RAID 5 uses an XOR system which is really punishing on a C
  • ECS Motherboards (Score:3, Informative)

    by W. Justice Black ( 11445 ) on Thursday August 28, 2003 @06:06PM (#6819476) Homepage
    Not offtopic (I hope), given the original poster's minor slam on ECS.

    I've been nothing but plesantly surprised by the ECS K7S5A/Athlon XP combo, because:

    1. SiS used to suck as a chipset manufacturer, and
    2. ECS used to have REALLY bad quality control.

    The surprise? SiS has one of the most stable chipsets anywhere (not the best performing, but performance is irrelevant if the drivers are wonky). Add to that the fact that I've worked with about 10 boards (all bought at different times), and I've yet to have a single problem with them under Linux or Windows (in fact, the SiS chipset seems to perform better under kernel 2.4.x with the SiS chipset than even Via). I've standardized on that combo at home and with the boards I've replaced at work.

    Summary: ECS has come a long way, and SiS even farther in the last couple of years. What the boards lack in performance, they more than make up for in stability.

    Geez. I never thought I'd be an SiS advocate on /. Wow.
    • I'd have to agree with you on the ECS bit. I picked up an ECS P4s5a motherboard for my p4 processor, and it's been nothing but reliable.

      Of course the only gripe I have about this particular board is the bios... but that's another company all together.

    • I'll agree with you on that count. When the Athlon 1200+ was considered a leading-edge processor, I installed a Duron 600 on a K7S5A rev 1.0 for a friend. I've partially supressed the memory, but its drivers were INSANE. They were incredibly horrible, and crashy, but I managed to finetune them to the point where the machine didn't crash. It took hours. (My friend bought the board - not me - so it was his fault).

      A different friend bought an Athlon XP 1800+ and K7S5A Revision (4 or 5, don't remember which)
  • by FreakyGeeky ( 23009 ) * on Thursday August 28, 2003 @06:07PM (#6819487)
    This is a topic that hits home for me. I have experience with Highpoint, Promise, and 3ware controllers. I used to use a Highpoint chip embedded on my motherboard. It performed fairly well, with the exception that it took two IRQs, and didn't allow my soundcard to function properly. I would get all manner of pops and clicks in the sound. It eventually drove me to the point that I bought a new motherboard and a Promise card. Ah, the Promise TX2 1000, how I hate thee. I will never buy a Promise card again. I spent more time rebuilding my system due to data corruption than I did using it to get work done. (Exaggeration) It caused unrecoverable drive corruption on three occasions in less than nine months. I switched again. Now I've got a 3ware 7506-4LP. I love it. It's a 64-bit 66MHz card, does RAID-5 and RAID-10, (in addition to RAID-0 and RAID-1) and it's fast. I've had it for a little over a month now without any trouble. Yes, it's more expensive than the cards listed, but I think it's money well spent.
  • You actually use Promise cards for important data?

    Spend a few more dollars and get a 3Ware card.
    They are fast, reliable, have low CPU usage and are supported under Windows, Linux and BSD.

    Please put this little article on your resume so that anyone with a clue can avoid hiring your cheap ass.

  • RAID experiences (Score:5, Informative)

    by JWSmythe ( 446288 ) * <jwsmythe@noSPam.jwsmythe.com> on Thursday August 28, 2003 @06:09PM (#6819502) Homepage Journal
    I haven't played with RAID's other than RAID5 much, but here's my experiences. Maybe they'll help your opinion.

    I've used several different external RAID5 solutions, including the Promise TX8000 and Radion arrays (and a bunch of no-name brands too). Those all worked beautifully, and survived failures without any significant problems.

    I've worked with four internal hardware raid solutions. Two were the Adaptec AA-130 cards years ago, and the most recent two were Promise SuperTrak SX6000. One belonged to a friend, and one went in my machine.

    My friend had several problems with his. I'll leave his story at that.

    I put together a nice dual processor machine for a large photo archive site. It needed lots of space, which is why we needed the RAID5. It also needed to take up as little space as possible, so we opted for putting 6 drives in a 2u case with the SX6000. The card was incompatable with the newer chipset of the motherboard. It took two weeks of daily calls to tech support before we gave up. A week later, they released a firmware update which addressed this problem. The SX6000 doesn't handle heavy read or read/write traffic very well. When we made it an active web site, the server would crash very frequently with errors about the array. If we kept the traffic slow, it worked fine, but that what we wanted from this machine. This array solution proved to be non-functional for us, so we made the machine a backup machine, so now we have like 600Gb of storage space to back servers up to. :)

    I've heard a lot of good things about 3ware, but haven't tried one myself yet.

    I've been experementing with Linux's software RAID's. I've used RAID1 and RAID5, and they both work great. I've had a drive fail on two so far, but for the number of drives we use, that's acceptable. They rebuilt fine sticking in a new drive, with very little performance hit. I do like that Linux gives decent statistics in /proc/mdstat .

    You seem to want multiple platforms, so I guess Linux software RAID isn't much of a solution for you.

    I can simply warn against the Promise SX6000. It should have been a good card, with Promise's reputation, but I was severly disappointed.

    • We're trying out both the SX6000 Pro (with enclosures) and 3Ware 7500-4LP right now.

      The Promise controllers have crappy Linux support. Apparently the kernel supports it. I just checked - RH drivers (old 7.x drivers) and SuSe 8.0 and 8.1 drivers are back up (they weren't for the longest time). We decided against them for Linux boxes based on all the problems people have had).

      3Ware cards have consistently had drivers and source avail, and the reviews on the web have been great. We have 3 installed, and they
    • Re:RAID experiences (Score:3, Informative)

      by Alan Cox ( 27532 )
      A few comments.

      Firstly - the Adaptec appears to simply be a third party controller with a different PCI identifier. How do we know - well if you add the adaptec pci idents to the siimage driver - it works.

      Pretty much all of the controllers out there are software raid and use BIOS/driver glue to implement raid. Several vendors ship the same hardware with different drivers to sell you a variety of priced cards according to pure s/w features.

      For standard PATA the Linux kernel uses its own md layer plus some
    • Re:RAID experiences (Score:3, Informative)

      by Nintendork ( 411169 )
      I built a high-traffic file server with the SX6000 and six 120GB SE Caviars configured for RAID 5. It's installed in an Abit motherboard and running NT4 Server with the latest firmware, BIOS, and drivers. Every once in a while, I get lost delayed write errors. I call support and they claim that it shouldn't be doing that with the latest firmware. After that, they would start having me troubleshoot the drives and do other "shotgun troubleshooting". To this day, we still get one or two of those error
  • I've been using this motherboard for quite a while and I like it, the HPT 370 chipset works fine as plain IDE ATA100 driver, I'm pondering buying some "twin drives" though and setting up some RAID. Anyone with some experience on setting up RAID on that hardware?
    • Anyone with some experience on setting up RAID on that hardware?

      I'll chime in - KT7-RAID chugging along in production land since fall 2000 in RAID 1 config. Only thing to watch for is the bios updates - make dang sure your data is backed up before you update the drivers/bios. Bloody thing won't die... go figure.
    • i've seen a LOT of kt7's where the caps on the motherboard begin to bulge at the top and eventually leak or explode, killing the board in the process. You might want to double check them. Its a well known problem, check google for references and the story behind it.
    • I had an ABit KG7-R with the same controller running a 0+1 array. The controller eventually went bad after about a year and a half. I kept getting errors, BSODs in Win2k, and finally I got a new KX7-R with an HPT372 chip. The saving grace? It recognized my array and immediately booted up. It was a godsend. Haven't had any problems at all since.

      If they made some 64bit/66mhz scsi raid 5 controllers I'd probably buy one for the new dual Opteron server I'm gonna build.
  • I don't know how much insight I can provide, as far as summarizing the "big picture" of RAID controllers in Windows. I haven't ever purchased any of the newer Adaptec RAID cards for use with Windows 2000 or XP, and the only ACard product I've used recently was an Ultra-66 EIDE card for the Mac.

    I do, however, own an MSI (Microstar) Pentium 4 motherboard with on-board Promise EIDE RAID support, and have been using it for quite a while now.

    So far, I guess the product basically works "as advertised", in that
    • Re: your intermittent freeze situation...

      I've had that happen to me on a number of different systems including my KT-7 RAID (-0) system.

      Possibly erroneously, I've put it down to thermal recalibrations since there doesn't appear to be any fixed pattern to them (e.g. when I know I'm hitting certain files that would indicate a disk-region specific problem). And I've never had a crash or corrupt data - just a system freeze for 2-3 seconds then carry on as before. Typically affects Windows boxen more than it a

  • More Information: (Score:4, Interesting)

    by Futurepower(R) ( 558542 ) on Thursday August 28, 2003 @06:11PM (#6819516) Homepage

    Added Information:

    I wrote the Slashdot story. I've gotten additional information since then:

    First, I don't see any evidence of low quality in ECS motherboards. Both ECS and Fry's employees say that the high rate of returns is due to the fact that the low cost attracts people who are very inexperienced at building computers. That seems right to me. An ECS sales representative mentions that Fry's uses ECS motherboards in the computers it builds. The ECS motherboards are suitable for business use. They may not be the best for overclockers or gamers.

    I wrote a long letter to Promise Technology Technical Support about the fact that Promise is allowing ECS motherboards with Promise RAID mirroring controlers to be sold without software that is necessary to monitor the health of the mirror. The letter is below, and represents my opinions at the time. Even though the national sales manager of Promise suggested I send the letter, there was no answer.

    Below the letter is all information and opinions that I had available at the time.

    ___________________


    TO:
    Kevin Hong
    Promise Technology Technical Support Engineer


    Kevin,

    Jason Turk told me to write to you about a problem with Elitegroup's L7VTA Rev. 1.0 motherboard, which includes a Promise RAID controller chip.

    Elitegroup says they have never been provided the FastCheck or PAM monitoring software for this motherboard. Can you supply monitoring software that is certified by Promise to work? The software is not on the CD supplied with the motherboard.

    We need not just software that appears to work, we need software that is certified by Promise Technology to work with this motherboard. Several people at Promise have told me that the software provided on the Promise web site for the Promise RAID controller adapter cards may not work with the OEM controller chips installed on motherboards. I suspect this is not true, but merely a Promise Technology marketing scheme. However, we can't risk selling these to our customers and finding later that there is some hidden serious defect.

    Thanks,

    Michael Jennings
    Futurepower Computer Systems

    _______________________________


    Complete Information:

    So that all the information to resolve this issue is supplied in one place, I have provided everything that I know and think below:

    Some versions of the Elitegroup L7VTA Rev. 1.0 motherboards are being supplied with Promise Technology's PDC20265R IDE RAID controller. Elitegroup supplies three of the four elements needed for a RAID controller. The motherboard and included CD have 1) Promise Technology's PDC20265R ASIC chip, 2) the latest version of the BIOS, 3) and the driver software.

    However, item 4 is missing. Elitegroup says Promise Technology never supplied RAID array monitoring software for this chip. Promise Technology calls this software the "FastCheck" or the "PAM, Promise Array Management" utility. Without this software, the user cannot know if a hard drive has failed in the RAID 0 or RAID 1 or RAID 0,1 array.

    This issue is Elitegroup's Case number RAE54616. (Note that Elitegroup also calls themselves "ECS".)

    Elitegroup's web page for the L7VTA product is here:
    http://www.ecs.com.tw/products/pd_spec.asp?product _id=327 [ecs.com.tw]

    The L7VTA V1.0 driver page is here, showing the latest Promise drivers:
    http://www.ecs.com.tw/download/dw_spec.asp?product _id=63 [ecs.com.tw]

    Promise Technology's web page for on-motherboard RAID controllers is here:
    http://www.promise.com/product/oem_ataraid_pdc2026 5r_eng.htm [promise.com]

    Note that this Promise web page mentions all four elements of a
    • with all do respect, ecs motherboards are NOT very high quality. Do you think any motherboard thats 20-30 dollars less then Msi, Asus, etc, is going to be paticularly good? I've had to repair and replace
      enough ecs boards for clients to not trust them.
  • joysticks.

    Hmm a mirroring controller...

    A mime controller? A monkey-see, monkey-do device?

    Or some kinky sex gadget. hmmmm.
  • they make good stuff.

    I have a 7000-2 (about $100) card in my bsd box. linux support is even official I think.

  • $80 is expensive? (Score:2, Informative)

    by gfilion ( 80497 )

    As you can see, these controllers cost from $59 to $85. Last weekend Fry's was selling a retail boxed 1800 MHz Athlon XP processor with fan included and an ECS motherboard for $59 total. So $80 seems like a lot for a little card with one chip and a flash ROM.

    Damn, we paid about $500 for an UltraSCSI 320 RAID controller [hp.com] and you think 80 bucks is expensive? And each one of the 75 GB drives [hp.com] cost $550, ouch!

    I guess you allready figured out that I work for the govn't. 8) It's not the same planet as the pr

    • Ever think that an U320 single channel raid controler paire with 10 or 15k drives along with battery backed up cache isn't in the same ballpark as the home users or small buisiness cheesy raid solution? Only the higher end cards like 3ware support hot swap. None of them support hot add. Dynamic reconfiguration without dataloss this is something that Linux dosent do right in software (yes I know there is a tool, the tool does function unfortunaly it dosent handle any sort of errors gracefully and it will
  • Adaptec's 1200A is Highpoint card with a slightly different bios on it. Heck I've heard you can flash it with highpoints firmware.

    http://www.internetnews.com/storage/article.php/ 79 7261
  • I use a promise Raid controller on the motherboard. As promise suggests, I use the synchronization feature from time to time, although as the author suggests, it doesn't really make sense that you should have to use this. I'm wondering what other people's experiences are with synchronization, and whether or not this is actually necessary, or even a good idea.

    I should note that the way that synchronization appears to work is by reading data from one drive, and creating a fresh, bit by bit copy onto the ot

  • It can work, but be extremely carefull, I never could keep Grub from breaking the mirror, and you half to tell the boot loader not to probe the ide drives - because the controller does SCSI and ide, but if you probe IDE it stops mirroring right and partition labels get confused. I did get lilo to work, but none of the utilities. You also need their closed-source hpt linux controller, which IMHO is picky and a pain to install with.
  • Gimme a break. (Score:5, Insightful)

    by delus10n0 ( 524126 ) on Thursday August 28, 2003 @06:34PM (#6819677)
    All of the cards listed are a joke. They are "semi-software" RAID cards. They are crap compared to the real deal, such as cards made by 3ware and the like. Cards with actual processors/cache/etc. on them, and not just some hook into a hard drive interrupt.

    If you want to go cheap, you're much better off using Windows 2000/XP's dynamic drives/mirroring ability in software.

    I never will understand why motherboard manufacturers use Promise/Highpoint chipsets on their "high-end" or "server" boards. Complete waste of time.
  • Software RAID (Score:3, Interesting)

    by Anonymous Coward on Thursday August 28, 2003 @06:38PM (#6819702)
    Software RAID (under Linux) is a better deal than spending $60 on a RAID card. The RAID drivers for these cards basically just implement software RAID anyway, so what's the point of having the hardware? The card is just one more thing to go wrong. Use the IDE controller that comes with your mobo.

    Software RAID has many advantages. You can monitor everything about the RAID array from within Linux. Drivers are no problem. It is well-tested and stable.

    Also, you can get better performance. I would rather spend an extra $200 for a dual-CPU mobo, get a second CPU, and run software RAID, than spend $200 to get a dedicated RAID card.
  • by Above ( 100351 ) on Thursday August 28, 2003 @06:38PM (#6819706)
    Unless I'm mistaken these cards don't do RAID anything. Indeed, they are ordinary controllers that have a few extra functions, all of which are basically hardware acceleration for RAID operations. The critical bits of the RAID are still done in software.

    With that said, if you're going to do software RAID, you might as well just do it. I've been using VINUM on FreeBSD for a long time, there are other options for FreeBSD and for Linux. The better ones take full advantage of the "dual read" property of mirrored drives at the kernel level. Best part, no special hardware required. If something breaks buy any old ATA card and you're back in business since it's all in software.

    If you need RAID-4 or RAID-5, a dedicated card might be a good idea. For mirroring I think software is superior.
  • RocketRaid404 (Score:2, Interesting)

    by theoddball ( 665938 )
    ...I've been running it for 6 months under Mandrake 9.1. Smooth sailing...I've had RAID 0 and 1 arrays on it without any problems. Also supports 1+0 and JBOD. The RR454 is out now, too, which supports RAID 5 (ooh, if only I'd waited...) Great value, though--can run 8 drives for ~90 bucks. Hit up pricewatch or something, they're easy to find.
  • I have a AEC6280R and it only runs on RedHat (it does not work with vanilla kernels)

    It is possible to get it to run (via a heavily hacked) 2.4.20.

    In other words this is *NOT* reccommended (and I have gotten no response from the maintainer of the package (aec62xx) )

  • Promise Experiences (Score:2, Informative)

    by lwells-au ( 548448 )
    I have had a some experience with Promise cards, namely the Fastrack100 raid series, on the Win32 platform.

    Generally they have performed reasonably well, with little hassle. However, there have been some major exceptions/issues:

    * BIOS and driver upgrade -- BIOS upgraded A-OK, but the driver achitecture changed slightly between revisions (ie. one dll disappeared) and Win2K just refused to load the new driver (kept asking for a dll that no longer existed), or revert to the old driver. Joy. Spent the weekend
  • Previously on slashdot there was a story [slashdot.org] about an article [tech-report.com] from The Tech Report that is really helpful regarding making a decision about IDE RAID card price/performance. From examining the article, it is obvious that 3Ware comes in with a better card for the money.

  • This was a Promise SX6000 btw and I was doing raid 5 under linux. I'll make this short. I had a drive failure, replaced the drive, the controller would not rebuild the array. Backed up all the data, rebuilt the array from scratch, reloaded everything. Time goes on. Another drive starts making an unusual noise. I happened to have a back up drive handy. I gracefully powered down the system and swapped out the noisy drive with the new drive. The controller would not rebuild the array.

    I said screw it a
  • I am about to buy an Adaptec 1200A because I have hunted around and found people near me who run Linux servers on them. The 2400 has support listed on the web. So I'm willing to assume the 1200A will work for me.
  • Intel's ICH5R south hub seems to provide good RAID support and is lots cheaper than the PCI cards.
    http://support.intel.com/support/chipsets/ iaa_raid /

    Sadly no Linux drivers yet, but the performance seems better than other cards due to no PCI-bus limitation:
    http://forums.overclockers.co.nz/show thread.php?s= &threadid=8156&highlight=raptor
  • Many of those cards are not really RAID cards. They add additional ATA interfaces and then have a BIOS and software drivers that do software RAID. That is why they are so cheap.

    If you want RAID under Linux, just use the motherboard ATA interfaces and software RAID; you'll get the same results with no driver hassles. IIRC Win2K (and maybe XP Pro) support software mirroring as well.

  • 3ware support story. (Score:4, Interesting)

    by Gldm ( 600518 ) on Thursday August 28, 2003 @07:56PM (#6820252)
    I bought a 3Ware 6400 back when they were new. Before the 6410 came out, and you had to get a full length PCI card for 4 ports. I got it through hypermicro.com, who I knew and trusted for all my storage purposes.

    Until the 3ware, I had been "The SCSI guy" in most circles. I was running all scsi systems starting in 1992 and woe betide he who suggest I add an inferior IDE device to my system. I had first spotted the 3Ware at PC Expo back when they were prototyping the 6000 series, and immediately scoffed at it as "just another IDE RAID wannabe." The 3Ware engineers overheard this and invited me to come over and play with their system and tune the benchmarks on it (standard ones like iometer, not custom in house things you can fake easy) to prove they were serious. I left their booth saying "I want one!" and repeating it to my friends for the rest of the show.

    But I digress. I had purchased a 3ware, to go in my new Athlon system. This was back in the old Slot A athlon days with the bad AMD750 chipsets. I had an Asus K7M, and the 3Ware was not cooperating. After a few hours of fighting with it, I put it in my trusty celeron system with the BX chipset motherboard. It still didn't work, so then I knew I had a problem. This was unfortunate considering I was leaving for college on saturday, and this was thursday afternoon.

    So I called 3Ware. I described the problem and had very little trouble (for once) convincing the tech support guy I wasn't some kind of moron. They believed me when I said I knew what I was doing when I put a system together, unlike most other companies. After an attempt to flash the card's BIOS to a good image, they said that the card most likely had a defective chip and would need replacement. They said they would gladly do it but their RMA system was down due to a server problem, and that calling hypermicro back would be the best option.

    So I called Hypermicro, and they say they'll be happy to get me a new card, but there's no way they could get it to me overnight (as it's now late afternoon). I explain the problem of leaving for college and they say they'll be happy to ship it to me when I get there. I wasn't happy about that.

    So I called 3Ware back, and explained what Hypermicro had said about being unable to replace the card before I leave. It's now about 8:30pm NY time, Hypermicro I believe is in central time, and 3Ware is on pacific time. The 3Ware support guy brings his manager on the phone (I didn't ask), and the manager says "Give me your information, and I'll have a card there for you. Send us your defective one back when you get a chance." So, 3Ware sends me a retail box card with the cables and all as a replacement for my OEM bare card, cross shipped, without an RMA number, and has someone take a car and speed to the FedEx hub in person to get it shipped.

    10AM NY time the next morning the card was there.

    The new card worked perfectly, and I was very happy with it. About 2 months after I bought it, 3Ware sends me an email. It basicly says the following: "We have implemented RAID5 support for your card in our new driver and firmware. You may download it as a free upgrade even though we had only planned to support RAID0, 1, and 10 on your product." How's that for support and driver updates?

    Also, after the 6000 series was retired in favor of the 7000 and 7500s, 3Ware sends me another email that basicly says "We know your cards are considered obsolete and no longer made, but here's a free driver that adds > 137GB disk support to your ata-66 level controller that shouldn't officially support that standard." And at that point they'd basicly retired the products, yet they were still developing new drivers and firmware for their obsolete parts!

    I now own a 7500-4 as my main controller, and I will likely be buying one of the 9000 series SATA-II controllers when they come out as an upgrade.

    Oh and I've never missed my DPT (unfortunately since bought and ruined by Acraptec) with its hardware RAID5 and cache or my seagate cheetahs or any of my other SCSI hardware ever since.
  • Promise "RAID" (Score:3, Informative)

    by cowbutt ( 21077 ) on Friday August 29, 2003 @04:47AM (#6822207) Journal
    The Promise RAID controllers, or the entry level ones at least (i.e. the PDC20276 found on many motherboards), are effectively just ATA controllers. The smarts for RAID0/RAID1 are done in the driver, with a bit of BIOS support (to allow booting from striped drives).

    As such, there are three ways of getting them working with Linux:

    Use the Promise RAID driver

    Use the Linux ATARAID driver

    Use the Linux md RAID implementation

    The first of those is handy if you're dual-booting with a RAIDed Windows installation and want everything to work. The disadvantage is that you'll be limited to certain kernel versions as other posters have already noted.

    The second option also allows interoperability with other OSs RAIDed on the same drives, but because the drivers aren't written by Promise, there may be some gotchas. The advantage is that ATARAID comes as standard with all Linux kernels, so you'll never be forced to lag behind through lack of driver availability.

    The third option is probably the most stable and convenient, as long as you don't require another OS to use the Promise RAID setup (md has not been ported to Windows, as far as I know!)

    I chose the md option as although I do dual-boot with Windows, I don't have any important information stored there. Note also, that because all the smarts are done in software, there's no inherent performance overhead in using md over Promise's driver.

    --

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