LTO5 Drive / Media head wear alert

[Genericus]

Bought 12 LTO5 drives in August, already replaced 3 - currently investigation points to abrasive tapes causing excessive head wear.

Symptoms include excessive cleaning requests - 3 or 4 a day, write errors, frozen tapes, drives going down.

Tape drives are in for Failure Analysis, should know more in a few weeks.

Here is my problem - I need to run a command to list not only my media barcode, but the hidden manufacturer information including who made it and when, that is read when the tape loads. Any thoughts?

[J_H_Is_gone]

Look at how busy you are keeping your drives, if the data is feed to slow you might be shoe-shining which will wear out your tapes and tapes heads real fast.

[Genericus]

My understanding is LTO5 drives automatically adjust their speeds to minimize shoe shining.

However, we write to a VTL and from there to the tapes, so we get good speed to tape.

Check out this post:

http://www.backupcentral.com/phpBB2/two-way-mirrors-of-backup-central-mailing-lists-4/general-topics...

and this one:

http://knowledgebase.tolisgroup.com/?View=entry&EntryID=271

Quote from that last link -

"we've discovered that some brands of recently available LTO-5 media are too "rough" and can cause undue head wear; specifically when used for archival tasks where the tape is used once - meaning that each job gets a brand new tape instead of backup scenarios where tapes are regularly reused and overwritten. We've worked with HP, and through them, the major media vendors and a new formulation has been produced that reduces this issue to inconsequential. The new formulation is much smoother in the case of a new tape and head wear is greatly reduced providing the more expected life cycle of the drives when the drives are used in an archival environment"

However, we are finding that just because it says HP on the case, does not mean it is HP tape inside.

I need to see if I can get a dump of my media, including the underlying media information.

[mph999]

Yes you can ...

I'm not sure what VERBOSE level is required , so just stick it up to 5 on the media server ...

VERBOSE = 5 in bp.conf 

Run a backup, the tape make will appear in the bptm log, read of the chip in the tape.

I guess I'm not allowed to tell you which of the few brands of tape are 'known' to be the most abrasive ...

.. but, due to this exact problem myself (some time ago) at the company I then worked for I only allowed Imation media or Fuji media to be used.

NOt many companies actually make tape, and HP/ IBM/ STK (Oracle) are all re-branded.  Oracle branded media, as far as I know, is made by Imation.

Martin

[mph999]

Also, all LTO drive ajust their speed to try and avoid show shining - but they all have a minimum speed they must run at, and as each new tape type comes out, this gets higher.

Also, each different brand of drive has a slightly different minimum streaming speed, but as a rough guess, I'd say LTO5 needs to run somewhere around 45MB/s to stream. 

Martin

[teiva-boy]

LTO5 Tape can only slow down to as low as 40MB/s (this depends on brand too, it could be upwards to 50MB/s too)

If you are using hardware compression, this number goes up to 80-100MB/s minimum!

If you're not multiplexing, then you're probably shoe-shining things.  Can you confirm your minimum or average write speeds?

[netbackup_rooki]

i have used! have used Maxell and Imation but have seen the best results from fuji in my 7 years life with NBU.

Fuji was also contracted by Oracle to make their latest T10KC media which I believe Imation used to make.

you should be able to contact your reseller/vendor and ask them replace these maxell with Fuji without cost.

[Omar_Villa]

Try using different commands to pull the data Vmoprcmd -shmdrive Tpautoconf -t Vmglob -listall -java Check those and tell us if where helpfull

[mph999]

No need to run all these commands, although they are useful commands for drive information - the bptm log is all you need.

From the bptm log, not only can you get the media make, you can also work out the average speed.

Martin

[Genericus · Accepted solution]

So - 11 of 12 drives in produciton and 2 of 2 drives in DR have been replaced - from less than 3 months of usage.

HP has been clear in maintaining that all HP tapes are within specs, they are working with us, which I appreciate.

HP has supplied us with improved tapes and we are trying them out.

the answer to finding the media information, with BPTM at level 5 and VERBOSE, on each media server, use this command:

cat {path to logs}/bptm/log.{date} | grep populate | grep VOLUME| grep -v DISKVOLUME | grep -v NULL | /usr/bin/cut -f10,14,15 -d " "| grep ^{tapeID 1st char} | sort -u