Surestore 215 (LTO 1) drive - low capacity

[Christopher Sheffield]

Thanks in advance... Here's our issue!

Our SureStore LTO-1 drive is currently only storing around 70-80GB onto our 100GB tapes (old & new.) In the past we have managed to get around 130GB onto these tapes with compression but this figure has dropped suddenly. The nature of the data has not changed considerably.

BackupExec 9.1 reports a "compression ratio" of ~0.8:1, which demonstrates that the tapes are failing to provide even their native capacity.

HP's LTT software reports the hardware compression as working, but the drive tests complain that there's a "large variation between channels" and sometimes fail.

We have used a cleaning cartridge to no discernable effect.

I have a number of questions:

1. If the LTT software is showing errors, does this confirm that our issue is not with BackupExec? - One of my colleagues contends that the drive seems to be okay because the compression reports as "working correctly" from LTT. Veritas reports the compression ratio as the ultimate total of data stored in relation to the tape's native capacity and I suspect that it's showing a loss of data due to a physical drive failure.

2. The channels error which appears in the logs seems to be undocumented. I couldn't find a mention of it in the LTT user guide or on the web. What does this mean, and it is a severe error?

3. Could this reduction in capacity indicate anything other than a physical issue with the drive?

4. Are there calibrations or other physical maintenance procedures we can perform to improve performance?

5. LTT reports that the drive should not be used anymore as a result of the drive test. How literally should that really be taken?

[Denis Mante]

Christopher,

It seems that you're not alone.
My LTO2 does exactly the same thing after a few months of very good service hours.

I've experienced a cooling problem in my server that raised the internal temperature to 55 °C (I'm french, sorry -;) - it might be the source of my problem. If so, these units are very fragile.

As I can find some second hand units on ebay at <$300 prices, I'm thinking about changing it if I don't find any cheap fix for this.

Did you solve your problem ?

[Christopher Sheffield]

Hi Denis,

We had a support ticket open with HP who eventually came back to us with a quote for repairs to the drive (as we were out of warranty). I took this to mean that they'd either concluded it was a physical failure, or that they at least couldn't solve the problem without looking at the drive.

The rate was in the neighbourhood of the cost of a new storage solution anyway, so we shelved the drive (and all the new media we'd purchased for it...) and installed a RAID-5 NAS at the other end of the building to back up to.

I'd open a support ticket with HP if you're still in warranty, otherwise look for a replacement.