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Hard Drives Instead of Tapes?
An anonymous reader writes "Tom's Hardware News weekly news letter has a very interesting article about Dr. Koch of Computertechnik AG who won the contract to build a RAID backup system for the University of Tübingen. Dr. Koch took several standard entry-level servers, such as the dual-Athlon MP, and add modern components and three large-caliber IDE-RAID controllers per computer, and a total of 576 x 160GB Drives."
What about being able to transport and store the information offsite?
I mean, sure tape isn't great, but it's a lot more transportable than harddrives.
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Programming is like sex... Make one mistake and support it the rest of your life.
There has to be a better way than relying on anything stored in magnetic format, optical I think woudl be preferable, and resistant to EMP.
But as large as harddrives are getting, the demand for backup will still be larger. I don't see this as taking over tape any time soon. People have been talking about how big harddrives are getting and about the demise of tape for a long time.
Just remember, if you can build something like this for backup, you can also build something like this for regular storage... and then what will you do if you need to back it up? Especially if you need to have a 6 month rotating backup...
I'm afraid it will be back to tape then...
One thing about tape systems that I didn't see mentioned was the portability of the media. Data recovery is still impossible if your backup burns up along with your server. I don't see anyone rolling one of these out to the offsite storage.
Maybe you could do it with a big pipe between your backup location and your servers. But I bet that would cost a bundle in bandwidth.
Also did anyone notice that typo on UPS (maybe they were on drugs USP)! It took me a good minute to catch it.
"I'm just here to regulate funkyness." - James Gandolfini, as Winston in The Mexican
sPh
I looked at doing something similar (but on a smaller scale) for my home.. but the amount of power that a hard drive based storage system takes is amazing. In additional IDE hard drives arn't know for their reliability.. :P (I've had numerous IDE raids fail spectacularly to the point I won't do that again...)
I ended up going on ebay and getting a StorageTek 9714 "Media Library" with 2 DLT 4000 drives in it. It takes a maximum of 2A of power.. (I've measured it much lower then that when the tape drives arn't in use..) This sucker will store up to 2.4 TB ( 1.2 TB uncompressed) in the 60 available tape slots..
The electricity saves more then makes up for the cost of the tapes.. (Also I expect the tapes to last approx 5-10 years.. I wouldn't expect that with the hard drives.)
--Mark
Right on. :) Most ./ers dont know anything about enterprise systems. Thats why you see them rail against commercial unices, because they only know Windows/Mac/Linux/*BSD. This carries over into tape backup strategy. They dont know anything about high-end tape technology, so you will see them suggest things like using large IDE harddrives because it sounds so simple on the surface. To do backups to disk right (and then to tape, because you really should) you need a real SAN though.
There is no way I would want to support that monster. I didn't see any mention of what happens when a drive fails. It's cake with most any SCSI Raid controllers. Look for the orange light, change the disk. Even promise makes IDE enclosures that do the same. With this system, do you have to take down the node when a drive fails? Sure it's a ton of space, but I'd give up some of the space for some easier administration. It only costs $70 per promise enclosure. That'll add about $12,000. So what. when you've spent $450,000 what's the big deal.
Oh PLEASE! I worked for, what was at the time, the 17th largest CC processor in the nation. Not so big, but lots of merchants. They bought a front-end (where your credit card terminals dial into), and built a backend settlement (so they didn't need FDR - who recently ROYALLY hosed everyone with a software update, including CHASE themselves. No, this software update was completely seperate from the SQL Slammer worm that took them down when it appeared.).
Complaince, usually done by the OTS (Office of Thrift Supervision), is NOT ISO 9000 type stuff. Financial companies are CHEAP. Never forget that. Whatever is the cheapest solution, is the one that is used.
As for tape backups - as an example: It took quite a bit of convincing to upgrade from the 4 drives that took two days to backup the whole network to a single Sont DLT drive. (Because $70/tape is a LOT of money)
There were no 'compliance' worries at all.
"I can't give you a brain, so I'll give you a diploma" - The Great Oz (blatently stolen sig)
No, you have $150 tapes that hold 1 TB of IT data. They can be written to at 60MB/s. Tape is compact, requrires no power, it is light, transportable and sturdy. The only major drawback as a backup method is the cost of the drives. (Which gets paid off quickly.)
To backup a storage pool with under a couple of TB of storage, tape is indeed stupid. If what you need is truly massive amounts of storage that does not need to be accessed instantaneously, tape cannot be beat.
Those aren't just backups, but also archives for auditing purposes. The analyist scandals of the last couple of years really helped drive home the need for these archives.
They of course are also important for business continuity, as Sept. 11, 2001 showed us when several large finacial firms had their data centers destroyed.
Offsite backups, whether tape or disk, present some pros and cons.
Pro: offsite is safer from local disaster effects.
Con: data restoration takes longer from further away.
Pro: high bandwidth connection makes moving data quick enough.
Con: high bandwidth connections are expensive
Con: high bandwidth connections are susceptible to disaster induced interruption
Overall, though, I like the random access provided by disk drives over linear searches of tapes. In case the network connection is broken to the backup site, you can easily load a couple of terabytes on cheap IDE drives into the back of your station wagon and bring them to any site you like and the effective BW will still be pretty darn good.
If you drive your station wagon across the continental U.S loaded with 3 TB of IDE drives in 3 days then you will be running faster than T1.
safer away from local disaster access time is high when locals need restoration big net pipe to far away but disaster that kills the network pipe ? maybe hard drives can be couriered back."Provided by the management for your protection."
cdr/dvdr uses a chemical substration process to have data written to it, and is nowhere near as stable as magnetic tape.
576 Hard drives.
Assume 5 years MTBF.
That end up being 100 Hard drive failures per year, about $10,000/yr, not counting labor.
Or 2 per week. ($200/wk), if efficient to replace then add another $100/wk for ordering, shipping, storage, replacement and disposal.
That's assuming good cooling and low usage (equivilant to an intermittant home user - which is what I expect a good backup system to get used to)
So, ignoring the cost of the initial investment, they'll be paying up to $15,000 per year to maintain this backup solution.
This is more expensive than many traditional backup methods, such as tape.
However there were a few 'gimmes'. Firstly, the array only has to last 5 years. Secondly they are using 5400rpm hard drives - much cooler. Thirdly, these hard drives have a 3 year warranty, which is better than most places will give you now.
So it's likely that the maintenance cost, in this case, is going to be low compared to the initial investment.
The real problem, then, is the tendancy to keep an old system long past its prime and original intent. Someone in the future will say, "Instead of junking the system and upgrading to new technology, let's just throw larger hard drives in there each time one fails and up the capacity. Eventually it will cost $10k or more per year, and they won't know it.
-Adam
Because I would be willing to bet that Quantum will charge a hell of a lot more per TB then this system cost (69TB for less than half a million is a bargain).
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
The advantage of backup to nearline disk is the near-instant access times for restores. You don't have to wait for a tape to load, and the read speed can be 50 megabytes/sec or higher if you use striping (RAID0,0+1,1+0,3,5) with multiple disks.
On the down side, you need to keep spinning a disk in a RAID environment to make sure the data is still good. Drives with one-year warranties aren't designed to sit on a shelf for 5 years and be powered back on. When drives fail, the RAID takes over and rebuilds a spare. You then take out the bad drive and replace it. To protect data, you need to keeps the disks spinning, and that consumes power. With lots of drives, it's lots of power.
One vendor has a hybrid solution that has disks both online and offline emulating a tape library. When disks aren't in use, they spin down. You get the best of both worlds - fast access time and storage that doesn't require power all of the time. It's great for nearline restores, but isn't designed (pricewise) for long-term storage.
In an enterprise world, I see people use SCSI- or FCAL-based SAN/NAS storage with nearline recovery data on IDE farms and long-term archive storage on tape libraries. The software to manage the data can be complicated and/or expensive.
In a budget world, I see people use IDE storage for both active and nearline and archive storage. The only difference between the storage is that the disks on the nearline or archive storage are larger and are used less frequently.
If you have data that gets read frequently after it is backed up or which requires fast recovery times, use nearline disk. If you have data that needs to be archived without any immediate requirements to read it in the near future, use archive tape.
-ez
Yes, I do have some 5 years old cd-rs lying around, they work fine. I was an early adopter because at the time I was tired of my ONE year old floppy disks and Syquest cartridges dying. Stop trolling.
Well, eight years, but who's counting? I've seen tapes younger than that lose their oxide. I've seen others physically degrade and get eaten when you try to read them, sometimes taking the drive with them.
OTOH, my father has 40-year-old punch cards that read just fine. (Course, that doesn't scale to terabytes.)
The upshot is that for long-term (>10 years) backup, have a refresh plan in place, where the data is periodically verified, and if necessary, extracted and copied to fresh media. (I have some 15-year-old files I did this to, moving them from QIC tape to CD-R. Nothing was wrong with the tape, but I only have one QIC drive, which could fail at any time.)
For my ultra critical data, I keep a backup of the backup locked in a bank vault.
I don't see off-site as a problem if you can afford a second unit hooked in with a high speed network. The problem I do see is hackers, and, well, administrator screw-ups. With all copies of your data on-line, if it should get accidentally or purposefully deleted, you're totally screwed. The only other issue is you're talking really large, you have a scaling limitation in power and weight.