Large IDE Drives as Long-Term Archival Media?

PlatterMan asks: "The question of how to cope with backing up disk drives which are rapidly increasing in size, onto tape and other backup devices which aren't scaling in size as quickly isn't new to Slashdot. Neither is the use of single, raided, and removal disks as backup devices, this has been covered numerous times on Slashdot in e.g. here and here. One thing I haven't really seen discussed however is the feasibility of disk drives as medium to long-term archival media, say 5 to 10 years. Like many people I'm in the position of now having multiple machines with a combined data pool of about 220 Gig, and backing up these onto DDS or DLT tapes is slow and manual to do, and expensive in tape costs. So I'm looking to add a removal drive bay to my primary backup machine and pick up a bunch of large IDE drives, so that I can do regular disk to disk backups over 100 Meg Ethernet (and for my machines which are in cages, over the Net) pulling out and alternating the backup drives on a 3-way backup cycle."

"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.

Thanks!"

Comments

Steve Gibson

[Jucius Maximus]

Please don't flame me for quoting Steve Gibson, but I think he's right on this account: "There are only two kinds of hard drives -- Those that have failed and those that will fail."

Hard drives are not non-volatile storage.

Why Tape Is Good

[Jucius Maximus]

Tape may be inconvenient but it is still a true backup medium. With hard drives, the reading and writing hardware are enclosed with the platters. So when the read head of the HDD fails, your data may be 100% intact on the platters but you can't get at it without professional help. How many other parts in the HDD could fail without harming the platters? A lot!

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.

Long Term Storage

[caseydk]

The Library of Congress is attempting to answer this question as they have huge amounts of media that is on highly degrading (nitrate-based films) materials.

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:Ask who's actually doing it.

[DJPenguin]

Well, don't know about LucasFilm, but Pixar use massive tape libraries (we are talking robots with 100+ drives and tens of thousands of slots.)

Incremental backups every HOUR, tape drives spinning all the time. They are a customer of the company I work for. (Veritas)

Re:Tapes *is* the right medium for long term backu

[glesga_kiss]

I've had numerous IDE hard disk failures, yet not a single data tape failure so far.

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:warranty period

[fishbowl]

"Who the fuck has 220GB of personal data? "

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.)