HP StorageWorks Ultrium 3000 SAS review

But Why?

Can anyone explain why tape backup survives? A quick on-line check indicates that these cartridges are more than twice the cost of an equivallent capacity hard disk - and that's before you buy the drive itself which is the cost of a high-end workstation!

The cartridge is about two thirds the size of the HD (a gap which could be closed by using 2TB HDs), has a roughly equivallent sequential transfer rate (and presumably much worse random access rate).

Are tapes alledged to be more reliable/longer lasting? I cannot speak to longevity from personal experience, but I have never found tape reliability to be good!

I use a pair of bare HD drives with a hot-swap drive bay. One is kept in off-site storage, the other near my PC (but removed and powered down when not actually backing up).

OK, I'm small scale, but I do not see how the economics can work out at any scale when the cartridges cost more byte-for-byte than disk drives.

By JohnAHind on 17 May 2010

Backup Discipline

There are plenty of situations where tape backup still works. They easily allow offsite storage, backup set rotation, write protection. Then there is really well developed backup software.
A set of write-protected tape cartridges in a fireproof safe are still a worthwhile price as an alternate to business collapse.

By milliganp on 17 May 2010

@milliganp

I grant you write protection - but I'm sure a simple technical solution could be found for that one. I do off-site storage and backup set rotation with HDs at the moment - why would it be easier with tape cartridges when they are as bulky and as heavy? I'd think a HD would stand a better chance of surviving a fire with any given level of protection.

Sure tape backup is better than business collapse, but my question is why is it better than much less costly HD backup?

By JohnAHind on 18 May 2010

@JohnAHind

OK I give you random access being slow but sequential data transfers on LTO3 and above is way quicker than any SATA hard disk drives on proper server grade machines (NOT DELL). And when you do a backup (which would be majority of the time), you want fast sequential read/writes rather than random.

Oh and I work for a DR firm who does full system recoveries from any type of media our customer base has and so far, disk based backups have been a bit hit and miss with too many issues compared to tape.

I would recommend using disk for a staging area but for off site, always tape. Archiving, again tape. When you have 20+ servers to backup, again tape. And if someone nicks a tape, they would first need a tape drive to read the data, the correct backup software and then the decryption keys (if encrypted). If a disk gets nicked, erase the data and flog on EBay. I know if I was a thief and walked into a server room, I won't be going for tapes, it would be disk drives.

The only people who I've seen using disk are those who don't spend enough money on DR and see it as not important to the business.

Very annoying!!!

By ssjandu on 18 May 2010

@JohnAHind

I'm not picking a fight. Do you have a real job, backing up real data? If so, the future of your employer -and all your fellow employees probably depends on data continuity.
Against this value any tape backup solution is small beer.
You need to convince your employer how important data is, get them to buy a £50k tape library -and give you a rise to reflect your importance to the business!
That which has no price has no value.

By milliganp on 18 May 2010

bristol_tape

Tape is much more physically robust. Dropping a tape especially in its storage case and you will recover you data. Will a hard disk drive stand up to a drop! Also hard disks are reluctant to spin up after a long period without power. Tape is still better for long term secure archive.

By Bristol_tape on 19 May 2010

@milligamp

I'm not picking a fight either - just trying to understand the value proposition of tape! You keep stubornly comparing the value of tape against NO backup, I want to compare it against HDs used in hot-swap mode.

I may be out of date as I only do personal backups these days, but when I did work in IT ops I learned (the hard way) NEVER to trust a tape backup unless I had personally made it AND verified it (halving the effective transfer rate of course) AND kept it in my personal custody.

I'm definitely getting the impression that tape survives mainly because it is "reassuringly expensive"!

By JohnAHind on 20 May 2010

@bristol_tape

I am thinking of applying RAID type lateral economic thinking to the backup/archive problem. So we note that HDs are much cheeper byte-for-byte than tape cartridges and then think about how to apply that to build a robust infrastructure.

Maybe the drives would be stored in specially designed fire-proof safes which would periodically spin them up long enough to keep their bearings lubricated and interrogate their SMART data, but not long enough to present a heat problem.

Certainly there needs to be well-designed transportation containers affording excellent shock protection.

For large robotic libraries, the robot would just need to bring the connector to the HD leaving it in the rack - much simpler than robotic tape handling!

By JohnAHind on 20 May 2010

Tape just works

I don't believe anyone yet makes a library for removable disk drives so replacing the the 6 daily on site, 6 off site and 20 on and 20 off site weekly backups with equivalent hard drives would be impractical to say the least, also with 8 LTO 3 drives going we can back up all our data in about 36 hours, this is not down to lack of speed but merely the number and size of files that are required which slows the process considerable. An on site virtual tape library may be worth a look but are not cheap, the next step up is data replication to a remote site but you still need tape backup for versioning and accidental deletions, and this is not a cheap option with some high bandwidth requirement 100Mbps min preferable 1Gbps then you start looking at redundant paths.......

Backup and DR is right mere. Keep it simple and do what works for you, but be prepared to change as your setup changes.

By Lorribot on 20 May 2010