Large IDE Drives as Long-Term Archival Media? 727
"Backups are of no use without offsite archival copies so I plan to take one set of disks out of the pool, and archive them offsite on a quarterly basis.
However, I've heard horror stories about the data retention and usability off older disks which have been shelved for archival, for example disk stiction - where people try to restore data off of a 4 to 5 year old drive only to find that the disk won't spin up due to solidification of lubricants, or that they've experienced data degradation.
I'd be interested in the Slashdot crowd's opinion on using large IDE drives as an archival media. Clearly one possible problem is being able to get hold of a machine in the future with a suitable IDE interface to plug them into for restoration, but I can't see IDE disappearing within 5 years (maybe 10 though). I'm more interested in experiences and opinions on the suitability of the disks themselves for long-term archival.
- Is stiction still likely occur on newer makes of IDE drives or have manufacturers beaten the problems which caused this in the past?
- Likewise how likely is bit drop-out and general data degradation over say a 5 year and 10 year period, and what do people think would be the likely maximum feasible time that a shelved drive would be usable for?
- Any suggestions as to how would I need to store drives in order to minimize these types of problem and maximise their feasible life as archival media.
Print! (Score:4, Funny)
Print out all your data in hexadecimal and store it in a large vault. If and when a data loss occurs you just need to re-type all the data back in.
yes I'm being facetious
Long Term Storage (Score:5, Informative)
Their answer? A huge RAID array starting at 180TB and growing steadily over time.
Your answer? Probably figure out which of the data is fixed and which of it changes and attempt to back up accordingly. Does all 220gb change on a weekly basis? That seems unlikely...
Re:Long Term Storage (Score:3, Funny)
> Their answer? A huge RAID array starting at 180TB and growing steadily over time.
Last time I looked [jamesshuggins.com], one Library of Congress was only 10TB, and I bought a 100G drive for $100.
So my rig sported a cool 0.02 LoC in my rig. I felt gr8. I mean, I 0wn3d.
Now you're telling me I only have 0.00055555 Libraries of Congress? I f33l s0 l4m3.
Bastards.
Re:Long Term Storage (Score:3)
This post brought to you by the Redundant Department of Redundancy Department.
Re:Long Term Storage (Score:3, Funny)
For home use, pretty obvious - MP3z, DiVX movies, and TiVO shows. Re-downloading the MP3z and pr0n^H^H^H^HDiVX movies would suck because you'd have to find and re-download the missing files. Likewise, re-recording the TV shows on your PVR would be a pain because you'd have to wait for your cable company to air them again.
You'd keep the RAID array up at home, and that'd be your media box.
But you'd still need a couple of 120G drives down at the local bank in the event of a fire at home. Or better yet, at your Grandma's house 100 miles away, if you live in an earthquake-prone area.
And while I've mentioned the time cost of re-downloading, this risk really isn't about piracy - even if you own everything on your media server, you can't re-encode your CD or DVD collection if said collection has been transmogrified into a melted lump of goo or shards of polycarb.
Every time you visit Grandma, or once every six months, whichever is less frequent, you swap drives.
(Just remember to pack the drives securely when you drive to Grandma's. And drive carefully. RAID won't protect you if all the drives in the array go sailing through the window at 60 mph ;-)
Re:Long Term Storage (Score:3, Insightful)
While "another HD" is probably the only practical backup for today's BIG drives, I personally would only trust that as a backup if it's powered up and running in a stable location.
Which isn't very helpful in this discussion.. but I think I'd make that "swap time" more like 3 months. In my experience, *if* a HD is going to lose data just from sitting around, it does so starting at around 6 months of idleness. Those that don't have the problem seem to keep data more or less forever, but (other than Conner HDs, which could be counted on to have the problem) I haven't found it's something you can predict in advance of the event.
Re:Long Term Storage (Score:3, Funny)
Re:Print! (Score:3, Funny)
Re:Print! (Score:3, Insightful)
BUT...
Consider that printouts on archival paper can be expected to last 100+ years. Tapes flake and fade, disks stick, cd's oxidize. Nothing else even comes close to paper! (well, maybe stone tablets...) Human readability is another plus.
For certain types of info, a printout is definitely the best choice.
Re:Print! (Score:5, Funny)
Not a pretty sight, let me tell you...
Re:Print! (Score:3, Informative)
If you're serious about keeping data for ever and ever, but also want convenience, you have to back up both ways.
1. Go ahead and keep data on that harddrive, but you're stucking buying another one to replace it, at least every year or so, just to make sure. This gives you the highest convenience for reinstating that data when (not if) it is corrupted.
2. Print it out. Print out all of it on non-acid paper with archival ink with the most expensive commercial printer that money can buy. Images, text, what have you. If you don't have a hard copy, you don't have the data for the long term. Once it's all printed out, put it in air and water-tight containers and then put it in a temperature controlled vault somewhere, preferrably underground so that it remains termperature controlled, even if power is lost for a long time.
Re:Tapes are a expensive waste of time (Score:4, Informative)
Burnt CD's (like you'd use at home) have a shelf-life of about 10 years. Then the medium starts to oxidize (the metallic film, not the plastic itself), and flakes..
So, you have a 10 year backup.. It all depends on how important your information is. If it's that important, I'd put it on a RAID5 where it can be monitored. As drives fail, replace them. Continue migrating to newer arrays in the future.. Expensive, but I konw perfectly well any drive will fail. I've had several hard drives, that would fail to spin up properly after sitting for a few days.. Some of them, they only way they'd start is if I hit the side of the drive with a screwdriver..
You have to expect failure of your medium. If he wants to be very sure, use multiple backup methods.. RAID5's in multiple locations, and CD's. Someone will need to monitor all of it occasionally. Make sure the RAID's (and their associated machine) are running. Make sure the CD"s are oxodizing...
Even floppy disks die of old age. I found a few boxes with Novell Unix. They're is years old, and most of the floppies couldn't be read. They were brand new, still in the sealed boxes and envelopes. I finally found a boot disk that would work, but it would bomb out trying to install under VMWare (I was curious).
Is that data really going to be useful to you in 10 years? That's the important question. People are all paranoid of loosing Email and the like now, but in 1 year they don't care about it any more. In 2 years, it's just wasted space. In 10 years, they won't even know who or what they were talking about..
Ten year old data (Score:5, Insightful)
And to top it all off, I back it all up to a DDS-4 DAT autochanger. Yes, those six tapes will only hold 120gb, but the amount of important data on my disk drive is far less than 120gb (it is actually less than 20gb, including the original 44.1khz .wav recordings of all my original songs, and fits onto one tape easily).
Do you *REALLY* need a backup of your .mp3 collection?! Probably not. Do you *REALLY* need a backup of all those ISO CDROM images that you downloaded for fifty versions of Linux and a half dozen versions of FreeBSD? Probably not. But that's the sorts of things that are taking up 80gb plus on my hard drives -- i.e., utterly disposable cruft. Which is true for most personal computers.
Um you've pretty much answered your own question. (Score:4, Insightful)
Without normal/regular use, you WILL have problems trying to read from them in 4-5 years time. Hell, the way most IDE drives are these days (note the recent reduction in warrenty time periods), you'll be lucky if the drives last 2 years even WITH regular use.
You could always ... (Score:5, Funny)
To restore from backup, search with Kazaa.
Re:Um you've pretty much answered your own questio (Score:3, Interesting)
t's the next AYB^H^H^H Soviet Russia (Score:5, Funny)
Not using SCSI like you should... That's a paddling
The right tool for the job is a tape drive, if you don't use it.... That's definitly a paddling.
Why Tape Is Good (Score:5, Informative)
With tape, the failure of a tape drive doesn't separate your from your data (unless it catches on fire with the tape in it or something.) You can just get a new tape drive and you are good to go again.
Thus, tapes are very good because the storage medium and the read/write hardware are separated and not interdependent.
Re:Why Tape Is Good (Score:5, Insightful)
Maybe it's just me, but after the experiences I've had the last year with crappy tapes, I'm surprised the "tape as a backup medium" idea hasn't been seen for the farce that it is.
Backing up to IDE or SCSI? Good short term solution, but I don't think I'd trust my backup drives for more than 1 year, tops.
Burn to CD? Good long term solution, just not practical due to the file sizes involved. Burn to DVD isn't much better.
It's time for something new. Hell, maybe it will turn into the next "killer thing" and revitalize the economy.
I vote for soft bubble memory
the absolute surefire way to back something up... (Score:3, Funny)
Get alot of archive quality, acid-free paper. Get a printer with alot of archive quality ink and print out the data in binary. Dots or slashes would work fine for the 1's and 0's.
Archive quality paper and ink lasts for hundreds of years. Should you lose the data on a magnetic or other storage medium, you could always run these papers through a scanner with some OCR and retrieve the data.
Sure, a fire or flood could damage these if you don't have them protected against that, but at least you won't have to worry about deteoriation of the medium.
Re:the absolute surefire way to back something up. (Score:4, Funny)
And just how many tons of paper are you going to need to reliably back up a terabyte in dots and dashes?
Assuming double the standard density (160 chars per line instead of 80, 132 lines per page instead of 66), which actually works out to quad density, you get 160x132=20120, say
- 20k per page
- 50 pages = 1 mb
- 50k pages = 1 gb
- 50m pages = 1tb
Now let's assume boxes of 5000 sheets. 10,000 boxes, at, say 20 pounds a box = 200,000 lbs, or 100 tons. Man, give me the toner franchise for this!Re:the absolute surefire way to back something up. (Score:5, Insightful)
300dpi gives us almost 11KBytes per square inch. Figure 70 square inches on a letter page with 1/2" margins. That's 770KB. Print full duplex and you're looking at 1.5MB per page, or roughly a floppy disk (coincidence?) You wouldn't want to back up your MP3 collection, but for an archival method that is likely to last 100 years it's not too bad. Factor in compression and you are probably getting a 100x increase in storage density over plain text. Kind of a neat thought.
Re:the absolute surefire way to back something up. (Score:3, Informative)
Re:the absolute surefire way to back something up. (Score:3, Insightful)
Most laserprinters can do 8-bit greyscale.
But for redundancy:
- Make two dots for each 8-bit piece of data, the 8-bits and it's complement. This is only good at error detection, although theoretically you could add error correction at a capacity cost.
- Add 256 calibration dots every few inches to make up for aging of the ink and media. We can assume that the cameras will have much higher resolution than the printer, so they can tell the difference even if the levels have faded together.
You could pack a whole lot of data on paper if you put your mind to it.
Re:the absolute surefire way to back something up. (Score:3, Informative)
Re:the absolute surefire way to back something up. (Score:4, Interesting)
If you were actually going to produce some kind of machine-readable dead-tree backup, it's more likely that you'd produce a type of 2D barcode that could be scanned back in and read. Assuming an 8x10" grid at 200 dpi (the remaining area can be used for alignment and checksumming), you could get about 390K per page (single-sided...you could also double that by making it a "flippy," and you wouldn't need a notch-cutter :-) ). You're still looking at a little over 5 tons for 1 TB, but it's an improvement. 200 dpi should be well within the abilities of currently-available laser printers and scanners. If you wanted to try 300 dpi, you'd more than double your capacity and get about 879K per page (single-sided).
Re:the absolute surefire way to back something up. (Score:5, Interesting)
But how about a 600dpi laser printer, 8"x10"?
For good readability, we can use:For (1,0) which gives us 3 dots per bit, or 200 bits per inch. A square inch would then give us 40,000 bits, or 5,000 bytes. A sheet of 8x10 then gives us 400,000 bytes. Or if you tweak the margins, 400k per page. So that's already 20 times your density. Increase the resolution to 1200dpi, and you can increase the data density to 1600k per page.
We can also use different encodings: Right now we use 9 bits to encode 1 bit of information (really, really, redundant). We can probably safely use the following encoding to double our data density:So this further gives us 2 bits of information in the same 3x3 square, which increases our data density another 2fold: 800k or 3200k per page. At 1200dpi, that's 3mb per page, so that 1gb == 333 pages, and 1tb == 333k pages. 67 boxes, or 134 pounds per terabyte.
There are more variations of course. We can increase density to 4 bits per 3x3 square. With a bit of thought, we can also increase the density up to the theoretical limit of 2^9 values in a 3x3 square, but we want to include some leeway for data redundancy...
So by doubling to 4 bits per square, we require only 70 pounds per terabyte. By doubling again to 8 bits per square, That's down to 35 pounds.
That much (little) paper... is actually lighter than a terrabyte of digital storage!
Re:the absolute surefire way to back something up. (Score:5, Interesting)
2000 sheets of 8-1/2 x 11, 20# laserwriter paper weighs 20 lbs.
First of all, this changes your estimate of weight from 100 tons to 250 tons.
Typical yield of paper: 125 lbs per tree
250 tons (500000 lbs) divided by 125 lbs per tree gives us 4000 trees.
440 trees per acre :)
This, after division, gives us 9 acres of trees destroyed for backing up 1 TB of data. Seem worth it?
PaperDisk (Score:3, Interesting)
Re:the absolute surefire way to back something up. (Score:3, Funny)
I know, I know, how do you get these people to do it? And how much will it cost? Easy, and I can get them to do it for free.
Name the backup DIVX_The_Twin_Towers.avi and put it up on Gnutella or WinMX. Problem solved.
Re:the absolute surefire way to back something up. (Score:3, Insightful)
Just encode your data into a pr0n video and share it on gnutella. That data will never be 'lost' !
Actually thats the real reason i thought of it (Score:3, Insightful)
So one way would be to both preserve a general specification of how to read the data, and then the data itself. So not only would you need a method of encoding the song onto paper, but you'd need to include the details of an algorithm - simple enough that people whose language may be very different from ours - can recreate it using their machines of the time. And then they can feed the data into it, and replay the music/video/whatever as we intended it to be seen.
Re:Why Tape Is Good (Score:4, Informative)
Bullshit. Tapes are intended as a short-term backup medium. Google for NASA magnetic tapes, and you will find a lot of interesting stories. Like e.g. this one [space.com]:
Re:Why Tape Is Good (Score:4, Insightful)
Re:Why Tape Is Good (Score:4, Informative)
While the failure of a tape drive won't separate you from your data (unless the drive damages the tape at the same time it fails . .
"During the National Archives' routine monitoring of the tapes'
condition, the analog reel-to-reel copies have shown no signs of
deterioration whereas there is an estimated 5-10% catastrophic failure
rate among the DATs in the collection. There appears to be no pattern
to the failures. It has occurred on new tapes that were recorded six
months ago, and it has occurred on tapes that were recorded six years
ago. It has occurred on all brands of DAT purchased throughout the
previous seven years. Accordingly, the archivists routinely reduplicate
these DATS on multiple copies. As insurance, archivists also transfer
DAT copies back onto analog reel-to-reel preservation copies. Unlike
the other preservation analog copies, these copies have not been
filtered and closely "mirror" the original tapes. Therefore, in the
future when technology has progressed, the archivists can retrieve
conversations that are extremely close to the original audio recordings
and enhance these with the latest technology."
Leading audio preservationists have issued their own warning [minidisc.org]. This company deals with audio preservation, and has some interesting things to say [rogernichols.com] about tape formats - analog and digital.
Of course, DDS tapes have supposedly been manufactured to a higher standard than their Audio DAT cousins, sport finer particles and stronger binders, and the format includes additional error correction and redundancy. Still, these issues with a modern tape format like Audio DAT are not an encouraging sign for those seeking to perform archival storage using DDS and it contemporaries. HP for example only claims a 10 year archival life [hp.com] for DDS. Contrast that with the 75-100 year lifespans [geocities.com] Kodak and TDK are claiming for CD-R.
These longevity issues won't just be confined to older tape backup formats though, if history is any indication. It's the nature of the medium. I think Sony is currently claiming a 30-year lifespan for AIT, and HP something similar for their new format, but of course we only have a couple of years' experience with them so far, and given the incredible data density of those formats, if something should go wrong with either of them the results could be catastrophic. Unexpected deterioration has certainly happened with tape before - witness this article [wendycarlos.com] composer and synthesizer pioneer Wendy Carlos put on her website, as well as her own experience [wendycarlos.com] with her older tape masters.
Hard drives certainly aren't a great archival medium either, but I wouldn't be so quick to assert that tape is superior. At least drives have the advantage of being sealed from the outside atmosphere, and contain within them all the logic and hardware required to extract that information in the future. The only big issues I can see are, will there still be equipment to interface with them in 10 to 20 years (probably, since IDE is so widespread) and will the drives still spin up in 10 to 20 years (who knows). It's that second issue that's the real buzzkill for HD's as a longterm storage medium. Manufacturers won't even issue a decent warranty on drives anymore. What does that say about their planned longevity?
Me, I think your best bet is DVD. But if you really want to be able to read that data in the future, I'd suggest copying it to at least two different formats, perhaps AIT *and* DVD. Don't forget to check on it every few years, too. If there's any sign of deterioration, you'll hopefully be able to make another clone before the failure becomes catastrophic (perhaps to a superior format that hasn't even been invented yet). If you want something you can just throw in a hole and forget about, sorry - that media doesn't exist.
Mission Critical Data.. (Score:4, Informative)
Re:Mission Critical Data.. (Score:3, Informative)
Re:Sod CD-R! Go With DVD recording (Score:4, Informative)
Cathy is avalible for download here [simtel.net]. According to these [simtel.net] sites [bookcase.com] it will handle many disk formats ("CD-ROMs, LS120, Iomega Zip and Jaz disks, or even diskettes"). The link to the home page [nbci.com] is broken.
Steve Gibson (Score:5, Informative)
Hard drives are not non-volatile storage.
Re:Steve Gibson (Score:4, Insightful)
I'm currently using Dell NAS machines as archival backups.
Bonuses (as I see them):
Online 100mbit access to old data.
Cheap!
Fits in a physically small space.
Negatives:
Higher failure rate than tape. Pop fizzle, your data is gone.
Difficult to take off site.
Long-term replacement isn't really an option. (for RAID replacement)
The way we negate the negatives (double negative, is that a possitive?):
-Failure rate / Data loss is countered by RAID
-Taking it offsite
-Long term replacement of RAID drives
Re:Steve Gibson (Score:4, Interesting)
Re:Non-volatile: no such thing (Score:5, Funny)
Moses: I bring to you these fifteen [crash], ten, ten ommandments.
I've had three hard discs die... (Score:2)
-Mark
Use another backup medium. (Score:2, Insightful)
Make sense?
Good.
GraniteDigital is what I use (Score:3, Informative)
I have 6 120GB Maxtor's and rotate them nightly, storing them in a fireproof safe, rated for paper storage. Granted, if a fire occurs, I'm not sure if the data storage would survive, but I think that would be the least of my worries, at that point. The Firewire works great and is very fast.
Re:GraniteDigital is what I use (Score:5, Interesting)
Paper-rated "fire safes" work by putting a media that undergoes a phase change at high temperatures, releasing steam in the process. (Think of the latent heat involved in freezing and melting ice, same theory is used to keep the interior of the safe at a reasonable temperature.)
The only problem is that paper tolerates steam fairly well. Ditto the smoke that can make its way into the safe. The paper may be damaged, but it is still readable. Computer media will be destroyed. Fortunately freezer-weight plastic is more than adequate to block the steam, leaving only small openings in the seal. Even this is modest, and the second bag is mostly to allow you to avoid smearing soot onto the media as you remove it from the bag.
Re:GraniteDigital is what I use (Score:4, Informative)
media starts to melt at 125 degrees F (52 Celsius)
A fireproof safe thats rated for paper storage only isn't going to cut it.
Good idea...except... (Score:3, Insightful)
I'm not a betting man, but I bet if that were a stack of DLT tape, you might still be able to read them after that hypothetical incident.
Re:Good idea...except... (Score:3, Funny)
Disk "stiction" (Score:2, Interesting)
I'm certain manufacturers have gotten even better with lubrication issues over the last 7 years and I don't think I'd waste too many cycles worrying about it. With the price of large capacity DLT/AIT tape these days, it sounds like backing up to cheap IDE disk is a viable option.
Cheers,
Just Another Anonymous Coward
warranty period (Score:5, Insightful)
Re:warranty period (Score:4, Interesting)
Tapes are designed for backups. If you seriously need to backup 200GB, then you are looking at DLT or better, and it ain't cheap.
Who the fuck has 220GB of personal data? Seriously, for the cost of backing up that much porn, you can just go down to the store and buy the legit DVDs. While you're at it, you can stop off at the record store and buy some albums so you can re-rip your MP3s.
Just because you have 220GBs of hard drives in your machines doesn't mean you need to back up every byte.
Pop quiz - if I wanted to back up this machine, do I
My documents (resume, web pages, GNU Cash files, email etc.) live on a server, where they are in fact backed up nightly to a second hard drive.
Every couple of months I burn a CD of the latest backup tarfiles. Cheap CDRs are a half-assed long-term archival solution, but the price is right.
Some things (Mozilla installer, service packs) are so ephemeral that they aren't worth backing up, i.e. when you need them there will probably be a new version available anyway.
What about my MP3s and pr0n? When I've got enough new stuff I burn a CD full. Every year or so it's worth re-burning the MP3s so that I've got the same genre on a given CD. When you've got Sarah McLaughlin, Mozart, Dead Kennedies, Suicidal Tendencies, Reverand Horton Heat and Johnny Cash on the same CD, there isn't a person in the world who won't make fun of you.
I did not recommend that no backup be performed. I said that I do not trust IDE drives for long-term archival use.
If you are determined to archive to IDE, fill your boots - it ain't my data.
Re:warranty period (Score:5, Informative)
I'm getting there, in audio data.
My own music, that I write and record, so, going down to the store to replace it isn't exactly an option.
It's also on DAT, and on CD audio, so you could say
I have a backup, but that's not really true -- the DAT is the source material, and a CD would represents one view of some of the data.
Am I going to buy a $65,000 SAN tape library machine, just because I'm getting into volume? (No.) Would I like an inexpensive solution that is less cumbersome than CDR? (Yes.)
Re:warranty period (Score:5, Interesting)
Who the fuck has 220GB of personal data?
And what's so weird about it?
A scan of a single frame of a 35mm film, on a high-end consumer film scanner will create a file... let's see:
The scanner is 4000dpi, so the resulting image is about 4000x6000 pixels. We are working in 16-bit-per-color-channel mode, so that's 6 bytes per single pixel. A bit of multiplication get you 144Mb. As a practical matter, the film frame is slightly smaller so your output TIFF file is about 120Mb in size. That is for a single 35mm film frame.
So raw scans of slightly under 2000 film frames will already hit the 220Gb figure.
Still think it's a ridiculous number?
Bad Idea.. (Score:3, Insightful)
Alternatives... (Score:4, Insightful)
Not a horrible Idea, just not a great one. (Score:4, Informative)
rock and chisel (Score:5, Funny)
Re:rock and chisel (Score:5, Interesting)
I know this parent was modded up as +Funny, but it's actually +Informative. "Rock and chisel" are the best thing we have, and there's a real trend toward using it more. Take a look at Norsam's HD-Rosetta [norsam.com]. It's an etched nickel plate designed to last for thousands of years. Vive la Rock & Chisel!
Re:rock and chisel (Score:4, Funny)
He's right, you know. Look at the info we're gathering from fossilized remains of dinosaurs! Once they found the petrified remains of a velociraptor next to a picket sign protesting the use of fossil fuels.
How often do you plan on replacing the drives? (Score:2)
Tape really isn't that expensive. (Score:3, Informative)
- A.P.
organize your data (Score:3, Insightful)
A lot of folks will say.... (Score:4, Insightful)
I counter with this: tapes rot too. In fact, any tape older than one year that I've had to go back to has been worthless (read: it had deteriorated data).
Tape is a really bad medium to trust, but we keep buying it because we can't think of a better solution. Personally, I think the way to go is just to give up and admit that disk is not cheap. You need to back up your data to a live mirror system with identical storage (hourly rsync does a nice job) and then you need to arrage a service that can back up your data to remote live mirror systems. Note that in both cases I said "live mirror". You don't want a backup sitting on a cold box because you never know the quality of it until you need it.
The remote backup part is expensive, but it's the only reliable way. You seed it by tape (full backup to tape, and mail them to the vendor) and then use dedicated lines to keep a regular incremental update going.
If one of those two backup systems fail you know about it right away and you fix it. No more tapes rotting on a shelf only to be discovered when your data goes south.
Re:A lot of folks will say.... (Score:4, Insightful)
DDS tape has a guaranteed data retention period of 2 years, but then you may face head alignment problems if you replace the drive. DLT and LTO have data retention periods of 5 years approx. Head alignment problems don't form a problem because of the nature of the mechanism.
This is however not the point. The point it that a harddrive is not an ARCHIVAL medium. Neither is tape. Harddrives are the work horses for on-line data and tape is meant as a BACKUP. Backup meaning a copy for safe-keeping under a very limited time (ie next week, when tuesdays tape is run again, or... well, you get the point... ).
CD's (CD-R(W)) offer a theoretical data retention span of 20-100 years depending on who you ask. So that is safer, but still not perfect.
A Service Level Agreement with a maintenance company would do the trick too, but is expensive.
But why archive? Doesn't an automated backup to a tape robot with a weekly rolling schedule combined with a RAID 1/5 solution for your single disk failures satisfy your needs? What is so damn important that you need Off-Site ARCHIVAL rather than off-site backups?
With the falling prices of both tape and disk cost per megabyte, it's affordable to keep all relevant data on the drives of the server and then do backup to tape if needed.
Just my 2$c.
Re:A lot of folks will say.... (Score:4, Informative)
First, only some personal data is critical, not the GBs of operating systems and programs I can redownload/recompile if necessary. Things like documents, saved games (you'd think it's unimportent until you play the first 2/3s of Fallout 2 five times and can't stomach getting far enough to see how it all turns out, because you'd have to play that 2/3s again...), email maybe, whatever, but some limited amount. 10MB can go a long way... that's a lot of programming, for instance. (Been working on a project for about half a year now and I'm just ready to break 300KB of code...)
Then, set up a live backup amounst all the disks you have on various machines. I use unison [upenn.edu] so that I can change files in the repository on any machine and have the changes propogate correctly, instead of the unidirectional updates rsync does.
Use symlinks to put everything you need into one directory, and tell Unison to follow the symlinks, not archive them directly. Then just run that every so often on the machines, and you're set.
Once more of my family gets set up with always-on connections, I intend to set up a family-level repository of backed up files with Unison, so that "off-site backups" are a weekly script run without intervention by the family, making off-site backups across the state (or country, or world) easy. This will protect the scanned pictures and other things in the family heritage easily and effectively.
Which reminds me, the first always-on connection just came online and I really ought to talk to that member about a reciprocating backup setup...
Re:A lot of folks will say.... (Score:4, Interesting)
Note that in both cases I The remote backup part is expensive, but it's the only reliable way. You seed it by tape (full backup to tape, and mail them to the vendor) and then use dedicated lines to keep a regular incremental update going.said "live mirror".
I agree wholeheartedly. Though, I would note, that IDE is the perfect solution for your redundancy. All you need is space. It doesn't have to be the fastest, or the highest quality mirror. Buying 20 IDE drives and having half of them fail is still cheaper than high capacity SCSI. Do a RAID 50 (IIRC, two RAID 5's - mirrored) offsite, and use rsync to mirror your data over your Inet line. Or string your mirror. Have your 'backup' offsite RAID rsync off the primary offsite RAID. I'd bet the only people who would have problems with that are the ones doing heavy graphics.
Check out Rackspace for your offsite needs, I didn't think they were that expensive, at least compared to an actual archival facility. Pick your favorite encryption method to secure it. Hell of a lot cheaper than a point to point.
Those people yelling 'insecure' apparently don't have an issue with their data being driven all around town. You want banking info? Just steal the grey box out the the '80 Ford Escort. OTOH, A 'man-in-the-middle' attack requires just that. So, if possible, host at your own ISP.
Tapes *is* the right medium for long term backup (Score:5, Insightful)
If you have the budget, get an autoloader so you can perform a full backup in one session, or two tape drives for that matter.
Personally, i am backing up 600+GB onto tape and it works well. I've had numerous IDE hard disk failures, yet not a single data tape failure so far.
Re:Tapes *is* the right medium for long term backu (Score:5, Informative)
You speak of not having tape failures, but you omit one important fact; how many times have you successfully retrieved data from tape?
IDE disks will fail from continual use, and that failure will generally be obvious, but what way do you have of knowing that you genuinely don't have any tape failures, if all you are doing is rewriting over the same tapes?
Re:Tapes *is* the right medium for long term backu (Score:5, Insightful)
"I have $500 to spend on a backup solution for my 220GB data pool, and I was thinking of buying 4 120GB IDE drives along with an IDE RAID1 card and useing the array for backups, anyone have other ideas?"
"No way, you are insane. IDE is horribly unreliable and you will surely lose your data. You need a $6000 tape drive, if you can't afford it you are better off with no backups at all"
We use it already (Score:4, Interesting)
With hard disks at less than $1/GB, it's so much easier to just buy drives. For our archives, we just buy those $15 drive caddies that allow you to swap drives in a drive bay. For nightly backups, we have a second RAID that mirrors our primary. I do worry about the nightly backup not being offsite, but at least it's in another part of the facility.
Fire, Flood, Theft, Hacking, Magnet, AC Failure (Score:3, Insightful)
I suggest you do what we do.
We have custom backup routines that mirror our onsite backups (in fire proof cement mounted safe) with our offsite backup server. It's not a direct switch on the offsite servers but it is very unlikely we would lose our data. HIPAA regulations don't allow us to store data in an accessible format offsite so we have it compressed and encrypted. We also store our programs in a bank vault to unenrypt our backups should a tornado hit or something that completely destroys our offices, note we're in oklahoma.
So to wipe us out completely we'd have to lose our office, our ISP's office (several miles away), our bank vault and me (as far as i'm concerned, since if I'm dead I don't give a shit about backups).
Big XII Champs! It's pretty sad when that is considered a failure from Sooners fans.
Re:Fire, Flood, Theft, Hacking, Magnet, AC Failure (Score:4, Funny)
That's the trouble with youngsters these days, no sense of commitment. I used to come back from the dead every night to keep an eye on the backups. And I had to walk 2 miles barefoot in the snow, uphill, both ways... etc etc
Ask who's actually doing it. (Score:3, Insightful)
Personally, for long term storage, I'd go with redundant backups of differing media. Maybe hard drives (stored properly in anti-static bags with silica gel), as well DLT stored in a similar fashion. Increase your odds of support by future architecture.
For daily backups, hard drives are surely the way to go. Faster, cheaper, easy to replace, longer lasting media in my opinion. Anyone who says otherwise is trying to cover their job as a tape changer.
Re:Ask who's actually doing it. (Score:5, Informative)
Incremental backups every HOUR, tape drives spinning all the time. They are a customer of the company I work for. (Veritas)
Slashdot - the "Jackass" of tech support (Score:5, Funny)
Can I use my laser printer to print on Gummy Bears?
Can I dry my cat in the microwave?
Can I put rice in my car radiator?
Can I unplug all the fans in my computer so it will run quieter?
Can I run 120 VAC on the spare CAT5 pairs?
Re:Slashdot - the "Jackass" of tech support (Score:3, Funny)
Eggs and baskets (Score:3, Insightful)
Crappy backups better than nothing (Score:5, Interesting)
On the other hand, I could spend (as I have) US$40 on a basic (a.k.a. el-cheapo) FireWire-IDE case, US$30 for 3 removeable IDE enclosures, and (eventually) about US$70 each for 3 60GB IDE drives. Total cost: US$280.
What do I sacrifice? Not much ... one of the drives might fail. At that point I'd just replace it with another US$70 capacity drive (which would probably be larger.) If I needed to restore something from backup, I'm already looking at up-to 24-hour old data, and if that drive happened to die, possibly 48-hour ... it's unlikely that all the drives would fail at once.
The advantages? I can use the US$780 I save for something else and I don't have to worry about shelling out another US$1000 every four years just to scale to "current" requirements. I don't know what the upper limit of an IDE drive is these days (i.e. what can the ATAPI bus handle) but even 200GB is pretty big for me right now.
Anyway, just a few thoughts. The basic thing is lower cost for nearly the same risk ... tapes fail too, you know. Remember, too, that this story would be very different if I had to handle 50 machines instead of 2.
May I recommend remote backup? (Score:3, Insightful)
Even better is that any flood, tornado, or fire at your house or business will not ruin your tape, dvd, cd, or hard drive backups. You simply connect to your remote backup location and restore your old data onto your new hardware. It's that simple, and it's cheap in comparison to spending $3,000 on a tape backup device that only stores 150GB of data per cartridge.
You may want to see if this remote backup company [usdatatrust.com] has services that fit your needs (I don't work for them, so it's not a plug). Basically, they state the following as the main appeals to remote backup:
Your data is continuously backed up as it changes, 24 hours a day, so it's always up to date. And it's stored electronically at Iron Mountain® data centers, where more than half the Fortune 500 protect their data.
No-Wait Recovery - Instantly recover your data to the point of failure, eliminating downtime and data loss from relying on a previous night's backup. And a unique web interface allows you to initate restores from any Internet browser, anywhere.
No Tapes, No Hassles, Lower Costs - Tape-less backup and recovery means no hardware or software to buy and a fully automated process requiring little employee time or resources. Lower your data protection costs while freeing IT resources for other tasks.
Why are you backing up? (Score:3, Insightful)
Short term failure
A luser makes a mistake, or there's a glitch in last night's source code library, and all your current data is foobarred. In scant minutes, you can restore lost data from overnight backups, (or even hourly incrementals), and you are the hero. Realistically, you're just doing your job, and you'll never get thanked for it.
Complete Failure
In the event of a building fire/server room flood/earthquake/Act Of Dog, then you may need to retrieve all your companies data from as near back as possible. This backup should be off-site, and as frequent as feasibly possible
Long Term storage
This is for archiving of a project, etc, and should be off-site. Also for archiving source code in case your company goes belly-up, so that customers can still use and modify your software (in escrow).
Ask yourself which scenario you are dealing with, then the answer as to which media is the one to use may be clearer.
Just copy it around (Score:3, Informative)
The "right" way to make your data reliable is with mirroring of various sorts. On-site backups are kinda silly except when you're using them operationally because you dont have the disk capacity to do otherwise for infrequently used data. Backing up to removable media should be exclusively for offsite storage.
So get two drives and mirror your data, and you're covered in the case of drive failures. If your worried about a whole machine going up in smoke, maybe do a nightly or hourly rsync to another machine across the room.
If your home data is important enough to need offsiting (usually a home user's "important" data amounts to what could fit on a CDROM, not 220 gigs - the rest is probably multimedia fluff that you can stand to re-encode or download in teh case of a tornado or fire), then consider rsyncing with a freind at night over your DSL or cablemodems in a mutual arrangement. Encrypt the data before syncnig it over if it's sensitive.
If you're a business with large volumes of data that need to be offsite in case of disaster, then the best practice is still tape drives of some sort, and an offsite storage service like Iron Mountain.
Perfect Storage Medium (Score:5, Funny)
M
Oh yea? (Score:3, Funny)
Sounds like P2P would be the ticket here. Just upload all your files onto Kazza and Gnutella and then let nature take its course, scattering them all over the internet.
Anybody see a problem with this? Seems like a "legal" use for P2P has finally shown up.
Five Points About Archiving (Score:5, Insightful)
Bits rot. Under the most perfectly controlled environment the damn stuff still goes bad. Be realistic, anticipate this, do everything you can to slow it down, but plan for it and make provisions when you first put your archiving strategy in place. Tapes are likely more robust the platters as there's fewer critical parts to go wrong but nothing is perfect.
Yes they're cheap but we've far less experience with these media then we do with tape and studies are showing that they dyes may not be as stable as first thought. Heck, there's even a bug out there that eats some of these. There's also the question of long-term standards in some cases like DVDs.
Nothings worse then losing one part of an archive at one site, another part at a different site, and being unable to easily reconcile the two to get a good whole set. Make sure that however you archive things, same media or different media, that partial archives can be reconciled.
Years ago there was a big scramble to recover the US Govt's 1950 Census. It had been stored on steel tape and the required Unisys readers were no longer. (Much of the data was available but the entire raw set wasn't.) Eventually a working one was built from cannibalized parts in museum and private collections but the lesson was clear: Don't depend on the readers. The same goes for the recent BBC Domesday Book debacle - nobody could read the optical disks. Any good archive scheme will call for the material to be re-read and re-transcribed regularly in order to ensure the entire recovery-chain still works: Hardware, software, OS's, etc. If recovery becomes difficult migrate the material.
All too often folks archive everything 'cause they're too lazy to determine what is actually necessary and what isn't. Combine this with the difficulty of later having someone unfamiliar try to winnow down the material and this becomes a real problem. Even worse is later trying to find the useful material among all of the dross. Establish clear policies of what can be archived and make folks justify their material. Just as importantly make sure the costs are clear up front, even to the point of charging them a rate covering several years of storage initially. Suddenly some pack-rat deciding EVERYTHING they've ever typed is potentially a goldmine isn't so funny. Lastly, run everything past Legal: Some of this they don't want hanging around any longer then necessary.
Some advice (Score:4, Insightful)
However, if this is going to have *any* chance of working, you will need to read the drives on a regular basis. I would pop each drive in a machine and (in linux) do a "dd if=/dev/hdc of=/dev/null" to read the entire drive. I would do this monthly.
Why you ask? Because modern hard drives are sophisticated and they auto-correct errors *before* they become a problem. Hard drives will do things like correct recoverable errors and rewrite weak sectors when they encounter them. Thus if you go over every sector of the drive every once in awhile, you will use the drives auto-correction features to your advantadge (and protect against the drive fading, which would be my primrary concern, not stickage (which is easy to fix)).
Some REAL long-term archival media (Score:3, Funny)
Not that new (Score:3, Funny)
Right now I am backing up 53 workstations to a hard drive file using Retrospect. I then copy the file to another server and backup that server. Somewhere, I will have a copy of those backups because it exists on two machines and a tape.
The cheapest, and most long lasting backup. (Score:5, Funny)
As disk space grows, so does your family/backup.
To see examples of how this works see: Mad Max - Thunderdome, The Bible, American Indians, The Fellowship of the Ring, Aesops Fables, and the Legend of How the Great Nog Vomited the Earth and Heavens in Ancient Times, Before the Oceans Drank Atlantis.
I have heard rumors that this is how Google archives.
My experience with long-term IDE (Score:3, Informative)
Make sure you select a very well-made drive, don't cut costs there. Example: I have a 20-year old Mountain HardCard that still works fine. However, I have had cheap 3-year old drives fail.
Bringing up point 2:
If you try it, make sure to use an "exercise" schedule for all the drives in your backup set. For example, once a week for each drive, plug it into a spare box and ensure that it spins up, spins down, and the read/write arm travels its full sweep. Maybe do some read/writes at various places on the platter surfaces, just to be sure.
It works for me, so I hope this helps.
Tower of Babel here we come (Score:3, Insightful)
Here's your backup script (Score:3, Funny)
RAID-1 plus drive rotation (Score:3, Informative)
So after a brief look at hardware RAID I realized that the software RAID support in Linux was all I really needed. Since this is my own machine, I didn't really need the hot-swap capability of a hardware RAID controller.
I bought two 100GB Western Digital drives and set them up in a RAID-1 configuration. A month later, I bought another drive, replaced one of the drives in the machine with it, and put the removed drive in the safe. A month after that, I bought another drive and repeated the process, this time moving the drive in the safe to an off-site location.
Every month or so I repeat the process, rotating the second drive of the array through my various offline storage locations. The real beauty of this (especially vs tape) is that I only need enough downtime to swap the drives and reboot the system; the mirror reconstruction runs in the background as I use the system normally.
The use of RAID-1 gives me complete protection against data loss in the event one of the online drives fails (though I've had no failures yet with the WD drives). If both drives are somehow ruined (e.g., by a fire within the computer), or if I accidentally delete something important, I have my first offline backup, less than a month old. If that's also ruined (e.g., my whole house burns down and the fire-rated safe fails to protect the drives it contains) I have my off-site drive, which is less than 2 months old. Obviously I could easily extend this process with more drives and more offsite storage locations.
Because the backup drives are regularly rotated into online service, bearing stiction should be less likely to occur. And if an offline drive were to fail when I bring it back into service, so what? It was about to get overwritten anyway.
Naturally, I also continually back up especially important files (e.g., email, work projects, documents, etc) to various machines over the network, as that's the easiest and most effective way to protect small amounts of data. But when it comes to periodic full backups of big disks, nowadays I just don't see any practical alternative to disk-to-disk copying. And RAID-1 is the easiest way to do that copying.
Re:Here's a tip.. (Score:2, Funny)
Tapes are NOT a long term archival medium. (Score:5, Insightful)
Even worse, tape drive formats keep changing - and since tape drives are guaranteed to wear out, where are you going to get a working tape drive to restore data 5, 10, 15 years from now? I've gone through 3 tape drives in the last 8 years - thank god I got a CD burner early, that data I can still read (although it's about time to start recopying stuff from 1996.)
Basically, if you entrust your data to tape long term, you have to continuously copy that data to new tapes, and or new tape formats. Where tape has traditionally shined is as a short-term backup format, although with the drop in DVD-burner drives/media, and the high-cost of high-capacity tape drives/media, this may no longer be the case (assuming you get some peon to do the big backup on DVDs, and you get to do daily diffs - otherwise, having a bank of tape drives is cheaper on staff time.)
Re:Tapes are NOT a long term archival medium. (Score:3, Informative)
So use a reliable tape format and store it properly. When stored properly, DLT has a shelf life rated in decades.
So use a tape format that is backward compatible. Today's SDLT drives can still read all the old DLT formats.
Check the shelf life of CD-{R,RW} and DVD[+-]{R,RW}. Most of the CD/DVD media is only rated for a five year life at most. Mastered CDs and DVDs will be readable for decades, but burned CDs and DVDs won't be.
The bigger problem with really long term backups is with the data format used by the backup software. If you use a backup program that only runs under Windows, what are you going to do when you need to recover that data in 10 years, and you only have Linux (or the other way around, the point still stands)? This is where Open Source software is good, because (assuming you can still find the source) you can always decode the data stream.
Re:IDE ? (Score:3, Interesting)
In that case, you could always just buy a new, cheap system for the purpose of reading the IDE disks, and keep that in the vault with the drives "just in case".
I'm not saying this idea with backing up to IDE is a good idea, though. Drop a tape on the floor while you're running to the tape drives for a critical restore, no biggie. Drop a drive on the floor in the same situation, you'd better hope your resume wasn't one of the files needing a restore.
Re:Why would your disks be (Score:3, Informative)
About all tape has going for it over disk, are physical robustness issues (the lack of the "stiction" problem that he mentioned, the fact that dropping a tape onto the floor is less scary than dropping a disk, etc).
Re:Why would your disks be (Score:4, Interesting)
Lets just say you go with 40GB DLT tapes...
220/40 = 5.5 DLT tapes to back up your data.
DLT tapes cost 50 bucks a piece. 6 tapes * 50 bucks = 300 bucks just for the tapes.
Oh yeah, now you've gotta buy a DLT drive as well... and if you plan on doing any real backups your not going to sit there and load 6 tapes in succession into the drive so your going to need a library of some kind. So, tack on 5000 bucks for a library... I'll make the assumption that your using a some free archival software, otherwise you'd have to tack on some big money for that as well...
So... 5300 dollar tape solution vs. 500 harddrive solution...
You choose...
Re:Has DLT tape ever worked consistently? (Score:3, Interesting)
I would regularly, I mean several time a day, move a tape from system to system for testing purposes.