EH841A - LT&T Drive Assessment reports Drive no longer recommended for use

[John Cunningham_4]

I have an extrenal SCSI attached EH841A LT03 drive that is now out of warranty (3.5 years old). I ran the LT&T assessment tests and it just gave warnings and then asked for the cleaning tape. After cleaning the Assessment test now reports Failure - Drive no longer recommended for use.

The reason I ran the tests was that I had been seeing greatly reduced comression - up until a couple of months ago I was seeing 700+ Gb per tape now I am lucky if I even get 400. The first test I ran before the drive assessment, was the compression test which reported success.

New HP tapes.

Data Protector 6.

W2003 x 64

Latest LT&T used

So are there any options apart from binning the drive and coughing up £1.5K for a new one?

TIA

John

[thomasr · Accepted solution]

I think that your drive has simply reached the end of its useful life.

The behaviour you are seeing seems consistent with increasing write errors, which cause the section of tape with the unsucessfully-written data to be skipped and the data rewritten.

If you had been getting 700GB and are now getting only 400, it suggests that nearly three out of four writes must be redone.   Sure -- you might end up with a tape that the backup application thinks was written successfully, even though many, many blocks had to be written more than once to get a successful write... but... if the head is in that bad a condition, what are the chances of having a successful read of that tape?

That said -- it's possible that another run or three of the cleaning tape could dislodge some 'stuck' crud that's causing the errors.    If that doesn't work and you want to go into totally unsupported territory, a carefully-applied lintless swab with denatured alcohol might be able to clean the head -- **IF** that is the problem.

In any case -- if this were my drive, I'd take one of my recently-written tapes and put it in a _different_ drive to see if I can successfully restore.    There's always a chance when a head is past its rated life, it is writing slightly out of spec and might be generating tapes that another drive might have trouble reading when you most need to.

On the bright side, if you do get a new drive, you might step up to an LTO-4 or LTO-5, both of which support hardware encryption, so that data once written to tape is safe from unauthorized reads so long as you keep the encryption key safe.   This hardware encryption is supported by most any business-class backup application.

[John Cunningham_4]

Thanks for that Thomas - you have confirmed my suspicions. We have decided to replace the drive which I have already done as we had a spare EH814A that belongs to another project but isn't needed for a while.

Cheers

John