Backup Tapes: Alive And Kicking

yootje writes "The Register runs an article about the future of backup tapes, which looks pretty good. Although some people say backup tapes are dead, tape systems continue to evolve. To prove that, The Register intoduces some new products that are about to come, like the SL8500."

Comments

Tapes are here to stay (for now)

[stratjakt]

Until optical media surpasses them in storage capacity, ease of use, and reliability, I don't see tape technology going anywhere. They serve a specific purpose and serve it well.

With CD/DVD Rot, tape sounds good

[grunt107]

Since prior stories have illuminated optical (laser) retention problems, tape does not seem as outdated as it once was. Tape's biggest problem now seems mainly cost. I had a 5GB Travan in a system and the per-tape cost was around $40. DVD blanks are around $1 for about the same amount of storage.

Re:Backups are here to stay...

[stratjakt]

We tried backup to disk in house to see how it would behave - backing up big SQL Server clusters.

The problem that killed it for us is when you're transfering to an 80 gig drive over firewire, you completely hog the hell out of the system, making it all but unavailable during the meantime. I don't know of any way to "throttle" the backup, there's probably some obscure tweak though.

Tape transfer rates are comparitively slow, which leave plenty of room for the computer to carry on it's tasks. Sure it might take all night to do a full back up, but the servers available during that time.

Tapes are nice..

[cK-Gunslinger]

..but what about recovery plans for catastrophic events? Those backup tapes sitting in a filing cabinet next to the server are useless when the building burns down or is flooded. I suppose you could just ship the tapes to another location, but then restoration becomes and even longer ordeal.

Re:Tapes are nice..

[emgeemg]

Which is why any good backup strategy includes moving tapes beyond a certain age off-site. Even so, I don't see your point--are harddrives suddenly impervious to flame?

Re:Tapes are nice..

[Zapman]

This is what off site storage is for. There are 2 companies currently begging for our business offering us just these services.

Remember, there are several main things that backups cover. It's important to remember which you're doing, and which are importante:

1) Disaster recovery. Full system restoration at a remote site (if the building collapses, will you be back up and functionional in $NUMBER hours?) This usually involves full system backups, using the most tapes. You can get away with weekly incrimentals, but beyond that you're doing too much tape shuffling at the restoration facility. This means a nightly backup, this means a LOT of tapes, and some largish libraries doing some serious throughput. Thankfully, your retention window is really short. 2 runs through that 'week' interval is usually all you'd need.

2) File recovery. This is long term storage, of mostly user data. "I deleted this file by accident, can I get it back?" "We dropped this table because it wasn't useful anymore, but we just discovered that this important monthly process actually does use it... can we get the data back?", etc. This doesn't take as much throughput or tapes per night as DR does (since you don't need the full OS image anymore), but the killer is the retention window. 6 months? A year? This is usually a policy decision for the people wearing suits.

3) Archival. This the data that 3 letter government agencies require you to keep for $BIGNUM years (usually 7 or so). Financial data, some customer data, etc. Thankfully, it's usually a thin subset of your normal data lode, and doesn't require much throughput to deal with. However, the storage requirements suck, and the media requirements are evil too. Just how do you restore a tape from a manufacturer who went out of business 3 years ago? CD's work well for this, as do some mainstream tape venders. Stay close to standards, since interoperability will save your bacon.

This is a huge problem. Backup to Disk is nifty, and makes lots of money for companies like EMC, but it isn't a good solution for anything other than DR. If you need long term file recovery, or worse data archiving, it's not going to work, and TAPE (or sometimes CD/DVDs) are the only game in town.

And many people forget the biggest thing of all: TEST YOUR BACKUP STRATAGY. Go offsite and try to restore some servers. How long does it take? How long can your enterprise survive? I work at a gas company, and parts of our enterprise are government mandatated to be back up and running in 12 hours. This is not easy.

Re:You're living in the past

[DarthBart]

A RAID-5 array with hot spares or a remote backup site is much more reliable and cost-effective.

BZZZZZT! I'm sorry, but thank you for playing.
What happens when the CEO deletes his stack of porn off the file server? Your RAID-5 isn't going to help you one damn bit. And maybe your company doesn't have the bandwidth to move the 100+GB of data on the fileserver to an offsite backup.

Backups don't just cover hardware failures. They cover people failures.

The problem with all these tape technologies...

[Gavin Scott]

The Register intoduces some new products that are about to come,[...]

The problem with all of these endless new tape technologies is that after they come they (or their vendors) tend to become lethargic and lose interest in the whole process so that six months later they're trying to sell you yet another replacement technology.

That's fine for something like a computer that can run the same software each generation, but for tape devices the need to change media is like having to re-code your application in a new language every time you upgrade the computer. People don't want to do it.

Most customers want a backup media that will still be viable in at least seven years because of legal requirements. That can mean needing to be able to buy a drive that can read their tapes 5-12 years from now. How many of these new tape technologies will have that kind of staying power?

The standard 9-track 2400 foot open reel tape served the computer industry for about 30 years, providing a standard storage and interchange mechanism for pretty much every computer larger than a PC. The Internet has rendered the need for an interchange mechanism less critical, but the instability in the archival storage formats is now giving people serious headaches.

G.

Re:Backups are here to stay...

[miked50]

They also forget to mention that you can't just disconnect a disk array, send it off site for 30 days, and expect to easily restore it when it comes back. With tapes, even if the OS it was originally backed up on is Windows, and the new OS was Linux, it will work (seemlessly if the backup software allows). The other thing that most people ignore besides the above mentioned sneaker quality is the larger cost associated with rack space, power, and cooling when using disk. I can stack a hell of a lot more TB/sq ft. with tapes than even some of the highest density hard drives, and I won't have to pay as much for power. Also disk systems produce considerably more heat than a tape library.

None of this really matters to small installations, but to enterprise installations these things are a lot more important.

Optical media is too small.

[nlinecomputers]

I sell servers to small SOHO type businesses, doctors, lawyers, accountants, etc. There is never large amounts of data but it does exceed the CD-ROM limits and DVD are just to unreliable. It is too easy to burn a coaster and they have poor shelf life. And even at 9gb they are often too small to put all the data on one disk.

And getting the office receptionist(often the person who will do the job of managing the media) to swap disks is often asking too much. It has to fit on one tape/disk/whatever or it isn't going to get done.

Tape especially DAT drives give most bang for the buck.

Re:You're living in the past

[thedillybar]

>A RAID-5 array with hot spares or a remote backup site is much more reliable and cost-effective.

Customer: I accidentally modified this file 2 days ago, can I get a backup copy?
You: Sorry, you're screwed.
Me: Yes, I'll have that restored for you as soon as possible. How can I contact you to notify you that it is finished?

We use RAID-5 and tape backup (which is off-site). The RAID covers disk failures; the tape backup covers user screw-ups and disaster recovery. And we've used both frequently enough to make them worth the money.

Re:You're living in the past

[minektur]

Bah. We backup our RAID-5, and for good reason. [...] When we got hit by a hacker a few years ago, after we had expelled him from the system we just restored from tape. Show me your RAID-5 doing that.

You're missing the point. Instead of buying a large tape jukebox, buy a SECOND large raid-5 array that is about 5x larger than the first and then write backup images of the first one to the second. Ie weekly full dumps and nightly incrementals - then you can have backups from any time in the last several days, or from each week going back a month or so.

Depending on your mix of restores and the egos of the faculty involved ("Ignore those students and fix MY problem NOW!" - dont get me started about lack of practical computer knowlege some CS professors have) you might be able to more easily find, and more quickly restore your backups from disk images than you might from tape. And you can MUCH more easily verify-after-write your disk images than you can your tape images.

You'll find that a big raid array or two will cost in the same range as a big AIT-3 jukebox in $/TB of storage.

You LOOSE offsite backup though and the ability to buy more media so you can occasionally make long-term archives.

A medium sized RAID-5 Array with a smaller cheaper single-tape drive would address both issues and might cost less. It would also certainly have quicker restores.