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Hardware Hacking Data Storage Programming Technology

NSLU2 Now More Useful 345

Posted by michael
from the oh-so-helpful dept.
NSLUG writes "The WRT54G's not the only hackable kid on the block. Linksys has a new device out. The NSLU2 is a tiny network storage device running Linux and it's been hacked to add SSH, NFS, an iTunes server, etc. Tom's Hardware is running a series of articles on how to hack the NSLU2. The first article is here and the second is here. Check out this page for details on getting into the box."
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NSLU2 Now More Useful

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  • by Stevyn (691306) on Wednesday August 18, 2004 @07:22AM (#9999722)
    This is another example of why linux is so damn cool. That little kernel can go anywhere.
  • by Anonymous Coward on Wednesday August 18, 2004 @07:23AM (#9999725)
    It shouldn't be this easy to let hackers break into the system, and there really shouldn't be enough tools in the OS to allow more functionality than the designers spec'd out for the device.

    Linux is a great thing, on the desktop. But in embedded systems, the kernel is too tangled to successfully create a small distribution that is at the same time useful and feature-limited.

    This is where operating systems designed from the ground up with modularity in mind fit the bill. QNX, iTron, and VxWorks all get around this hacking problem by not providing the tools for hackers to change the system.
    • by julesh (229690) on Wednesday August 18, 2004 @07:28AM (#9999753)
      It shouldn't be this easy to let hackers break into the system

      Why would you want to prevent them? It drives sales of your products.

      the kernel is too tangled to successfully create a small distribution that is at the same time useful and feature-limited.

      I don't agree. It is perfectly possible to do this, and know several people who _have_ done it. The issue is, it isn't worth the effort. It would take several weeks of developer time to determine exactly what is needed and what isn't, whereas there's actually no problem with including unnecessary features. So that's what happens.

      Don't get me wrong, I think QNX et al are very cool systems, and there are many situations where they are more applicable than Linux. But I don't see anything wrong with Linux here.
      • Provided you are selling your hardware at a profit no problem, but if you are using the hardware to subsidize the sales of services or consumables then big problem ala "iOpener"
      • The kernel has *nothing to do* with the security issues. The security flaw is the lack of checksumming at boot time of the firmware image, which in this case is a Linux OS.

        Now, if they used a Linux BIOS, they'd be in better shape for that kind of security testing. I'm completely serious.
      • Well, one of the problems is, you just know there are going to be morons out there who decide to hack their hardware, screw it up, then call tech support saying it's broken. That's going to cost tech support time as well as potentially sending replacement units to folks who have screwed up their system on purpose.
    • by bostonkarl (795447) on Wednesday August 18, 2004 @07:49AM (#9999922)
      Oh, please. Who are you with your shoulds and should nots. Did you read how folks originally broke into this box? They *physically* unplugged the USB2 disk from the NSLU2 and mounted the USB hard disk (which is NOT part of the NSLU2) directly to their Windows/Mac/Linux box(es). They then modified the password file from the Windows/Mac/Linux box. Being able to modify this device is a good thing. There is a collaberative spirit surrounding the newgroup associated with the folks developing *useful* applications to run on this the device. Linksys sells a very interesting and inexpensive piece of hardware with the NSLU2. A big reason it is inexpensive is that Linksys (1) lowers software development costs by using a ubiquitous operating system/software that it (Linksys) doesn't need to develop and (2) doesn't pay outrageous licencing fee for proprietary operating system/software that provides the same funcationality as freeware (Linux). QNX? You think the password file associated with QNX couldn't be modified in the same manner? VxWorks? Common.
    • Linux is a great thing, on the desktop. But in embedded systems, the kernel is too tangled to successfully create a small distribution that is at the same time useful and feature-limited.

      Not true at all. Check out uClibc [uclibc.org] and BusyBox [busybox.net]. In fact, I may get one of this NSLU2 boxes *just* to hack on it.

    • Hrmm, I believ you got it backwards, linux will never be a truly great desktop replacement, however one of its strengths is the embedded systems, along with server stuff. ever seen a sharp zaurus PDA? the latest ones are very nice and offer more than any other pda on the market.

      Also, another flaw in your comment, the kernel is only "too tangled" if you compile...say, modules, and x86 support with x86 hardware and other features that dont exist on a simple little embedded board.
  • Avaks RoadRunner 64 (Score:5, Informative)

    by koody (575863) on Wednesday August 18, 2004 @07:31AM (#9999772)

    A-Link has released two new ADSL-modems RoadRunner 64 and RoadRunner 64AP. Both have many advanced features, but the one that cought my eye was that they are Linux based. I bought the RoadRunner64 (without WLAN) and I've gathered some data about it.

    You can find out more about the product either by looking at the RR64 feature sheet [a-link.com] or by checking out the guides and firmware [a-link.com] page.

    The platform

    Both versions use LSI Logic's HomeBASE platform with the AR901 network processor. The only difference is that the AP version has a WLAN module manufactured by Zydas.

    The platform consists of AR901 processor (ARM922), the AR8203 analog-to-digital adsl chip and the AR229 USB/Ethernet chip. Note that the value of these parts is a measly $21 while I paid 80 EUR for the complete modem ;-)

    Specs

    Processor: ARM922 @ 200MHz integrated in the AR901 chip
    Flash: 4MB
    RAM: 16MB SDRAM
    Ports: 4 RJ45, 1 RJ11, 1 power
    Other: Zydas 802.11b WLAN (In RR64AP only)

    One can simply ssh to the box. It has tftp support and you can mount nfs partitions, so setting it up to distribute kernels for a ltsp setup would be possible. Cool little gadget, I must say. Unfortunately the software isn't 100% yet, at least not the firmware I have (first release). I got the source by asking politely by e-mail, and after it suddenly borked on me, they changed it for a new one without any hassle.

  • $80 street price (Score:4, Informative)

    by ediron2 (246908) * on Wednesday August 18, 2004 @07:35AM (#9999806) Journal
    Buy's got it for $71 if you use a $5 off coupon. Nobody /. 'em until I finish my order, though... thanks!
  • antivirus anyone? (Score:5, Interesting)

    by 241comp (535228) on Wednesday August 18, 2004 @07:36AM (#9999818) Homepage
    How about someone installing ClamAV on this puppy? Have it auto-scan the HD every so often and keep your NAS nice and virus-clean!
  • by vasqzr (619165) <vasqzr@netsc[ ].net ['ape' in gap]> on Wednesday August 18, 2004 @07:43AM (#9999870)
    As neat as this is, I can't help to wish there was a little more security in devices like this. What about when someone adapts some worm code to install a custom, ddos-zombie installation on the thousands of Linux-powered Linksys/etc routers out there?
    • I thought the "security" was broken only by physically accessing the device.

      Given that there would be several variations of installed firmware, I think it would cut down on the number of worms that can hit all of them.

      Even then, that is just a hypothetical exercise right now, I don't remember any big worms that targeted the Linux kernel, nor any proof-of-concept demonstrations.

      And most of these hacked units woould be behind firewalls, I think you need some of them to be direct connected to the Internet t
    • What, a worm that breaks into your house, removes the hard-drive from your network storage and edits?

      Shit, run!
  • Eh. (Score:3, Insightful)

    by iamdrscience (541136) <michaelmtripp.gmail@com> on Wednesday August 18, 2004 @07:45AM (#9999888) Homepage
    It seems like there would be only a marginal intersection between the type of people that buy network attached storage devices and the type of people interested in hacking their network attached storage device. I mean, I would think most people who are able to hack their NSLU2 are also the type that have an extra computer around that they would use instead.
    • by bfree (113420)
      I can think of two good reasons for this, future proofing and form factor. If you are installing any sort of large number of these, you could be looking at keeping them around for quite a while in which case you don't really want to have to scrap them all when Linksys decides to stop support. If your not buying many then it's all about the form factor and simplicity I guess, 130x21x91 is pretty small and on a small network could be brilliant for popping on and off portable storage, even just as a backup
    • I mean, I would think most people who are able to hack their NSLU2 are also the type that have an extra computer around that they would use instead.

      My extra computers I could use instead are noisy as hell. This thing is probably dead silent. It'd be great for a server (mail/web etc.) that I could run 24/7 in my bedroom.

      • by stevel (64802) *
        I have the NSLU2 and use it as a file server for backup. But even more useful, it serves my MP3 collection to my Audiotron. It and the USB disk sit, tucked away, on a shelf in my basement. It draws far less power than a PC and is silent (other than the disk.)

        It also has a built-in backup client that can back up files from other shares on your network. I don't use this, but it's a nice feature.
    • by Tux2000 (523259) <alexander AT slashdot DOT foken DOT de> on Wednesday August 18, 2004 @08:41AM (#10000466) Homepage Journal

      I would think most people who are able to hack their NSLU2 are also the type that have an extra computer around that they would use instead.

      Sure you could use an old PC for that job. But that PC has at least a 150W PSU, often 200W, 250W or more, and almost every PC has at least one noisy fan. My tests on my ex-router (really old Compaq 486 without harddisk) show that a PC needs at least 40W AC power when IDLE, and much more with newer CPUs. According to the Datasheet [linksys.com], the device is specified for 5VDC @ 2A. USB ports must be able to deliver 0.5A each, so the "real" machine needs nothing more than 5V @ 1A. This means you never put more than 10W into the device, with a low power USB storage device, 5W should be possible IMHO. With a common wallbrick PSU (50% heat, 50% output), this translates to 20W AC power under FULL LOAD. With a modern switching PSU (20% heat, 80% output), and a low power USB storage device, you need about 7W AC power. That's what a modern ATX PC draws in standby mode (so-called "off").

      Did I mention that the NSLU2 has no moving parts?

      Tux2000, not related to Linksys except that I own a hacked WRT54G.

    • STABILITY (Score:5, Interesting)

      by interiot (50685) on Wednesday August 18, 2004 @08:52AM (#10000599) Homepage
      There are several important differences between a little system like this and an old computer:
      • low power... makes the box silent, and the power-supply is simpler/cooler and likely to have a longer life
      • simpler software... unlike an old box that potentially has a ton of different things running on it, this has a smaller set of very stable software that's likely to continue working forever
      • easy backup/restore... the ROM image is 16MB, so it's something you can put a copy on all of your computers, and is trivial to restore. Whereas if your random machine lost its installation, how long would it take to do a re-install?
      • it's small and cheap... yes, spare computers are cheaper, but whereas it's feasible to maintain and store 25 NSLU2's in my computer room, the same is not true of spare boxes... it'd be too noisy and much less stable.
      Where we're going with this is having separate hardware to do each little network task. Since they're all running on separate CPU's, if one of them does die, the other ones will be fine, and will likely continue running for a long time.
      • audio output/video playback (one per room)
      • firewall/NAT/WiFi
      • DMZ services
        • apache
        • sendmail
      • network attached storage
      • backup/restore
      • X10 network interface
      • ...
      These are things you simply want to always work, and don't want to screw around too much.
  • RAID? (Score:3, Insightful)

    by 241comp (535228) on Wednesday August 18, 2004 @07:46AM (#9999903) Homepage
    Could it be hacked to run software RAID 1 or RAID 10 on the attached hard drives? That would make it more useful for small office environments.
    • I might be getting my RAIDs mixed up, but I think RAID10 requires 3 disks, and according to the writeup on Linksys's site it only supports 2.

      I suspect you would need to flash the firmware to achieve this. I'm not sure if any toolchains are available that would allow you to ensure you had a working kernel before you did this... i.e., you stand a high chance of writing off the device.
      • I thought RAID 10 required 4 drives. If you're going to the trouble to enable software RAID, I'm sure you could enable it to mount more than 2 HD's (using a USB hub to provide the necessary ports).
        • I thought RAID 10 required 4 drives.

          You may be right. I've never been entirely certain of which RAID level was which. I only ever use RAID 1.

          If you're going to the trouble to enable software RAID, I'm sure you could enable it to mount more than 2 HD's (using a USB hub to provide the necessary ports).

          That may be true. Another alternative that I just thought of is to set a cron job to do a regular backup of changed files to the second disk. That wouldn't require any kernel or core system updates, s
          • Probably something that can provide incremental backups like reoback would be good (take less space, compressed). Or if you don't care for that, you could run something like Unison on the drives and actually use both of them (increasing throughput, decreasing latency) and let it figure out the discrepancies.
    • Could it be hacked to run software RAID 1

      I'd think it'd be easier to hack it to do hourly rsyncs or snapshots between the two drives. For my applications, that'd be sufficient.

    • Why stripe? It's onl got 10/100 out the front thats only 12.5 MB a sec so striping isn't going to gain you anything, linear append and a LVM implemtation would be realy nice for a small office. Think about ok your first HD is full plug in a second drive and we can either expand the existing partition onto it, append it's space or simply move it all without second of downtime. LVM snapshots are also probably better than a mirror to deal with a disk failure as mirror sets tend to currupt at the same time s
    • Re:RAID? (Score:3, Informative)

      by turbine216 (458014)
      The unit already does scheduled disk-to-disk backups, without any hacking, which should cover whatever data integrity concerns you may have.
  • by vasqzr (619165)
    As expected, the passwd file showed the user accounts I had created with a /dev/null for the shell. But there were two accounts that had a real shell: root and an interestingly named account--ourtelnetrescueuser, that looked like a back door account used for debugging or recovery purposes.

    root:WeeOvKUvbQ6nI:0:0:root:/root:/bin/sh
    bin:x:1 :1:bin:/bin:
    lp:x:4:7:lp:/share/spool:
    mail:x:8: 12:mail:/var/spool/mail:
    ftp:x:14:50:FTP User:/:
    nobody:x:99:99:Nobody:/:
    ourtelnetrescue user:scFf7ZMXBMl4I:100:100::/ho

    • root::0:0:root:/root:/bin/sh

      Don't you ever let me see you type something like that again, you hear me?
    • Re:passwd files (Score:3, Insightful)

      by julesh (229690)
      *nix n00b question, maybe, but why not just blank the [root] password out?

      Err... to stop anyone on your network from connecting and wiping all your data / nicking your pr0n collection?

      One thing I have just noticed...

      admin:sclzZZfodiRXY:502:501::/home/user/admin:/de v /null
      test_user:scEPG0VnVyqmE:2000:501:::/dev/nul l
      test2:scEPG0VnVyqmE:2001:501:::/dev/null
      test3 :sc50wKPq.zChw:2002:501:::/dev/null


      Its using the same salt for every password. This is horrendously insecure...
    • So for curiousity sake, has anyone cracked the passwords?
  • by 241comp (535228) on Wednesday August 18, 2004 @07:52AM (#9999966) Homepage
    Well, get a USB flatbed scanner with GPL drivers and you can have a network attached scanner. Come to think of it, there are probably lots of USB devices that one could share with this box. It could even do wiring closet security monitoring with a USB webcam and a remote machine which analyzes the images for movement. The possibilities appear endless (provided working drivers can be obtained and installed on the box).
    • Well, get a USB flatbed scanner with GPL drivers and you can have a network attached scanner.
      i'm having trouble understanding the purpose of this... if the scanner's so far away, using it via the network is going to require a bunch of back-and-forth between the client computer and the scanner. if it's close, then you could just plug the scanner in directly....
      • For instance, my small office typically has 2 desktops and up to 3 laptops in it at any given time. Usually only up to 4 people but sometimes 5 are present. We have a network attached printer (HP LaserJet 5MP) for our printing needs. A network attached scanner could be placed next to the printer and any of the 5 users could scan. This isn't an issue if your small office only needs $50 scanner quality (just buy everyone one) but if you need the quality of a $250-$500 scanner, that's a lot of money you'd
  • Now, if I remember proiperly, USB 2.0 has a speed near 400 Mbps. This thing has a max network speed of 100 Mbps.

    Sigh... If only they had included a 1Gbps port on this thing, I'd get somewhere near the speed I want. And yes, I do have a Gigabit network running at home, and only a few laptops aren't equipped with Gig cards. And yes, it does make a speed difference.
    • USB2.0 can't sustain 400mb/s. It can rarely even achieve that speed during normal operation. If we were talking firewire, then yes, it would have been better, but with USB2, you won't even notice it.
    • Doesn't USB 2.0 have a max throughput (max, realistic's probably 320 after overhead) of 480 Mega*bits* per second, where as my Hdd has a max throughput of 100Mega*Bytes* per second. Multiply by 8.

      This is just recollection from memory, so I might be wrong. Don't think so, though. See conversion chart here [unitconverterpro.com]
  • by Bushcat (615449) on Wednesday August 18, 2004 @07:54AM (#9999986)
    What's the real-world performance on this kind of device like? And why is it limited to two USB devices (other than the obvious fact that there are only two USB ports on the thing)? I'm considering one simply as a network backup device.
    • by Tux2000 (523259) <alexander AT slashdot DOT foken DOT de> on Wednesday August 18, 2004 @09:14AM (#10000951) Homepage Journal

      Speed: The USB 2.0 Hi-Speed FAQ [usb.org] tells us that the maximum speed of USB 2.0 is 480 Mbit/s. The maximum speed of parallel ATA is 133 MByte/s = 1064 MBit/s, plus it does not have the "ATA over USB" protocol overhead. Serial ATA does 150 MByte/s = 1200 MBit/s, IIRC. The ethernet interface of the device supports 100 MBit/s. Modern harddisks can not deliver 133 MByte/s = 1064 MByte/s, but they become faster every day. Flash memory can be that fast, at least for reading.

      Power: Each USB port must be able to deliver 5V @ 0.5A.

      Now do the maths: You can see that already a single USB device can deliver more data than the ethernet port could transport. The CPU (according to http://www.batbox.org/nslu2-linux.html [batbox.org]) is an XScale CPU with 131.48 BogoMIPS, roughly comparable in Performance to a slow Pentium II. I'm sure it can't handle much more than 100 MBit/s Ethernet and two USB 2.0 ports.

      Adding a second USB port is convenient to copy data directly between USB devices, e.g. for backup or upgrade purposes. But adding more USB ports costs 0.5A per port for the PSU, making it much more inefficient for each added port.

      Tux2000

  • by ObviousGuy (578567) <ObviousGuy@hotmail.com> on Wednesday August 18, 2004 @07:55AM (#10000000) Homepage Journal
    I don't get it.
  • I object (Score:2, Funny)

    by nslu (532403)
    I, nslu(1), am just as useful.
  • by Goo.cc (687626)
    I am going to order one. I think that it is cool that this little device is hackable.

    And shame on those who would poo-pah on others for having fun with cheap hardware. If you can't understand why this is fun, then don't do it.
  • by Glyndwr (217857) on Wednesday August 18, 2004 @09:42AM (#10001371) Homepage Journal
    Lots of people are claiming that this is much cheaper to run than a dedicated ATX server, but they are forgetting you need to power the hard disks too. In my (limited) experience, powering desktop 7200rpm disks from USB is very dicey, so you need externally powered hard disk boxes for them.

    Based on UK prices turned up in 30 seconds by Google, so probably not the cheapest to be had, but never mind.

    NSLU2: £60, 5V/2A power into device

    Cheap USB hard disk box:£35, 50-80VA power into the PSU brick (based on the one on my desk). I'll use 70VA, to be on the safe side.

    So, outfitting one of these for two hard disks would cost around £130. Assume a 60% efficiency plugpack for the NSLU2 (which seems conservative) and total power consumption would then be around 160VA.

    In comparison, my server has an Athlon 900Mhz, a couple of fans, the same two hard disks, and a 300W PSU. Let's assume it's highly loaded and actually draws around 250VA; I'll ignore power correction factor for these calculations.

    At 10p/kWh, the NSLU2 costs 39p per day to run, and the server 60p. If I upgraded to the NSLU2, it would take over 3 years to get a ROI from a purely financial point of view. Unless I've gotten something wrong, in which case I'm sure some clever slashdotter will correct me in a few seconds :o)

    So, on purely financial grounds, perhaps hard to justify. Still, it's nifty, it's a hell of a lot smaller than my existing server, and it would reduce the noise in this room nicely by eliminated a few fans too.

    Update: hmmm, PC guide [pcguide.com] reckons it's more like 10W for a hard disk under use, suggesting the rather high sounding 50-80VA max draw are probably for 10,000rpm disks spinning up or something. Even assuming 15W to be on the safe side changes things around a lot; assume 75% efficient PSU plugpacks just to look on the bright side, and we get 20W per hard disk and 13W for the device = 13p per day. Break even is now about 9 months; not too shabby, given the other benefits.
    • by WuphonsReach (684551) on Wednesday August 18, 2004 @11:13AM (#10002598)
      Most 5400rpm drives are 6-7W idle and ~10W when seeking. The 7200rpm drives are a bit more power hungry, 7-10W idle and 10-13W seeking. Dunno about 10k RPM drives, but for a low-power fanless server you'd want to stick with cool running 5400rpm drives anyway. (Those numbers are from the manuf websites.)

      Here in the northeast US, 10W of power draw costs $0.60/mo. Figure a 25W low-power CPU like a VIA C3, another 10W for the motherboard, plus 2x7.5W for a pair of 250GB 5400rpm drives in RAID1. That *should* clock in at around 50W on average, and maybe 40W if the disks spin down. The NSLU2 draws 10W (max) plus another 15W for the (2) USB hard drives for a total of 25W (being conservative). So the cost savings is around $1/mo.

      Unit price for the NSLU2 is $80, plus another $50 for a pair of USB enclosures. Definitely cheaper then building a mini-ITX system (est $300-$400, not including drives).

      All that being said, I prefer my toaster-sized mini-ITX linux server.

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