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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."
This is a much better solution than tape, really. It's predictable that the industry will probably move in this direction, now that the hardware is cheap enough and of high enough capacity to serve this function.
Imagine: instant recovery. Your backup could be a usable image of your live server.
So a BIG RAID is somehow safer than many small RAIDS? Backups aren't just for the heck of it...some of them are required for compliance, i.e. the financial industry.
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...
I know of a lot of people (myself included) who use multiple external hard drives in rotation for their backups. Especially now with servers' hard drive capacities growing so fast. I just specc'd out a fileserver for a department at a cash-strapped public institution, and a tape drive big enough to backup the system's disk would have been more than 50% of the cost of the computer. Not to mention the cost of tapes. Instead I set them up with two firewire hard drives. For their needs, the reliability/longevity/cost equation made hard drives the best solution.
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
The unfortunate thing is that tape technology just hasn't kept pace with disc technology. Back in my first job, we were backing up $1,000 20MB drives onto $40 200MB tapes. If that held true, today we would have $4 tapes that would hold around a terrabyte of data...
But, we now have $100 tapes that hold as much data as a $100 hard drive.
We switched over to hard drives for our backups at our (modest) server facility. Late last year we spent $2000 on a system with 600GB of RAID-5 protected storage. That holds current and historic backups, for around 6 months with our current load. We then weekly dump the current data-set off to a removable 120GB hard drive, which we take off-site.
Tapes are SO dead...
It works great.
Sean
Right now, Sony is shipping Super-AIT tapes. The cartridges are about 3/8 of an inch thick, and each holds 500GB, before compression (which is integrated in the drive hardware). The drive can read or write at 30MB/s, before compression. With typical IT compression of 2:1, you get just under 60MB/s. The cartridge goes for about $150. Just try and get a terabyte of disk for that much. No, the drives aren't cheap, but they get paid off quickly.
Yes, disk is good if you need instant access to your backup, and for small installations of under a couple of TB, using disk backups make sense, but for larger data pools, tape is far more economical.
Also, as mentioned in the article, disk is terrible if you need off-site backups. In addition, a tape library consumes far less power, takes up less space, and produces less heat than a drive array of the same capacity.
Basically, the death of tape has been predicted for years, but it hasn't happened yet.
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
Instead of building a giant kluge, why didn't they buy a few Quantum DX-30s? Each one only takes up 4U, holds 20 drives, and the internal software emulates a tape library so it easily integrates with enterprise backup software from Legato or Veritas. If your environment requires off-site storage, you could attach a tape library to clone the backups and then store the tapes off-site.
Haven't you ever put a CDR in a microwave? Pretty lights! (I take no responsibility for any damage to your microwave...)
Dupe posts are
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.
A hard drive is sensitive to vibrations and has too many moving parts. The only reliable backup media is punch cards. Just don't store them near liquids.
Karma: The shiznight, mostly because I am the Drizzle.
First, nothing begins if not opening
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."
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
Just a disclaimer to start things off - I am in the tape library business, so take what I say with a grain of salt. OTOH, I am a technical person, so it isn't going to be a polished marketing twist either.
.53 failure rate is good (I'm not sure what the published rates for new tape drive technology is) but the rate 5 years down the line is going to be much higher in my opinion.
The article mentions one major drawback, the inability to do offsite storage. You could work something out with offsite mirroring, but bandwidth costs at 70TB would get excessive. Not to mention needing the same hardware setup on the other end.
The other major advantage that tape has over disk is the archive ability. Once you write a tape, that data is static. I can have it sit in a slot in the library for a long time. Since this system is only designed for 5 years, archive is not a big deal, but a lot of industries it is huge. The ability to alter data on a disk drive seamlessly is a lot easier than to do on a tape.
The person who mentioned the shock/vibe values for a disk drive VS a tape cartridge: #1 I have dropped PLENTY of cartridges, and have only has one chip a corner. That chip did not affect my ability to use the tape further. Additionally, if the housing is destroyed, the process to spool off the tape, and splice it onto a different tape is not that difficult. I would not loose the data permanently. If there is a major mechanical failure inside a disk drive, getting the data off the platters is a lot harder.
I would be interested in seeing numbers for throughput of the system, power consumption, backup window lengths, average restore time. Some of these might stack up favorably to tape, others might not.
The comment on moving to optical as a backup medium - maybe someday, but for now the space needed/time to backup to optical does nto compare well with tape. A DVD of 4.5 GB VS a tape of 100GB (Currently available, yes I know blue lasers will improve that)
As for a robot failure, worst-case scenario, you put the tape in the drive manually. Realistically, at least at our company, we have solved this problem for our customers by providing the ability to easily replace components. This can happen either with a field engineer, or even the customer themselves. Generally all you need is a Phillips screwdriver, 20 minutes max, and the ability to follow instructions.
Again, I'm not in the sales department, so I can't quote costs, but a 435K total cost for 70TB is not that cheap. With tape systems, a lot of the cost depends on how fast the backups need to occur in. I could build out a 70 TB system with 1 drive, a SCSI connection and a huge wall of tapes relatively cheaply. As you add more drives, use fibre or gigabit Ethernet interfaces, etc costs go up, but access times go down. Cost can also be brought down by not going with the 500 lb gorilla of the field - StorageTek.
Yes disk is growing, but generally it does not replace tape, it only pushes it back a layer. This won't change for a while.
For some years there have been rumours of optical tapes with capacities in the several hundreds of GB or even several TB per cartridge, but no products that I am aware of so far.
Still I think that this misbalance between tape prices and HDD prices cannot last.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted and ignored otherwise.
I can appreciate the appeal of building a massive system from commodity hardware, but it states that the entire system was $435,000. After some rough calculations, a smilar system using apple xserve-RAIDs would run around $300,000, or $135k less before host computer costs, and would most likely be much easier to maintain. Plus, five racks of xserves would look pretty bitchin' :P