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New Tapes do not compress

I am running BE 2010 R3,(Ver 13.0 Rev 5204)

If I introduce a new tape to the media set, it will not compress at all, and is less than 1:1 in fact.

Have tried all the options mentioned about with no difference.

Has anyone seen this and have been able to correct it?

19 Replies

Hi,   I moved this to a new

Hi,

 

I moved this to a new discussion due to you using BE 2010.

So I assume you've done the following:

1. Made sure you're using the Symantec drivers for the device?

2. Turned on compression on the library/autoloader, and within the job itself?

3. Tried both hardware and software compression in the job to see if this changes anything?

4. Made sure that you're backing up data that can mostly be compressed (ie. image files are already compressed and don't compress anymore).

5. Run LiveUpdate and made sure you're running SP2 and any subsequent patches?

Thanks!

It could be that you are

It could be that you are backup up data which is already compressed, like zipped and picture files, sound and movie clips.  Compressing data which are already compressed may result in a file much bigger than the original.  Likewise, if you are trying to compress encrypted data.  Read my article below on this subject

https://www-secure.symantec.com/connect/articles/compression-short-explanation

Craig - Yes we have done all

Craig -

Yes we have done all those things. Let me clarify some more on what is happening. I have a two week daily tape rotation Using LTO-3 tapes (10 tapes) and do a monthly backup using the same jobs used for the daily backups.

We are running on newly installed M-S Server 2008,64 bit platform. Upgraded to Backup Exec 2010 from Version 11 at the same time. HP Proliant ML350 server with interal HP tape drive.

The 10 tapes compress fine, but when I introduce a new tape for the monthly job, it does not compress at all, and actually writes considerably less than 400 GB to the tape. I have tried different brands of tapes, with the same results.

The compression on the 14 tapes also produces a wide range of results, with the most recently introduced tapes (probably under V11) experiencing less compression than the older tapes.

Thanks for your help.

See details on reply to

See details on reply to Craig. Data is not the issue.

Same job, 1 day apart, on different tapes, completely different result.

New Tape writes only 263 GB on 389 GB of tape space.

Old Tape compresses 456 GB of data to 389 of tape space for a 1.2 : 1 compression.

Have you tried to erase the

Have you tried to erase the tape first before using it?

Erase tape first

It is a new tape, so not sure what you getting at.

re: New Tape writes only 263

re: New Tape writes only 263 GB on 389 GB of tape space.

Assuming this is with compression turned off, it sounds like you might have an issue with your tape drive.

See if this applies:http://www.symantec.com/docs/TECH193200

 

 

...if it is a new tape, BE

...if it is a new tape, BE doesn't erase it. So erase the tape manually and see if you get the same error again.

Another alternative is to use your drive manufacturer's diagnostic tool to erase the tape (stop the BE services), and then start BE up again. Once done, then run a backup.

If this still doesn't work, and you've tried 3 different types of tape manufacturer, check the drive out with the drive manufacturer's diagnostic utility.

A new tape is formated when

A new tape is formated when it is labeled and inventoried as part of the media set. Isn't this same thing as erasing it?

LTO tapes never get

LTO tapes never get formatted, at least by BE.  "format"ing a tape is typically used by older tape technologies.

When BE does a "quick erase", it simply re-writes the header.  This is basically the same as then a tape gets lapeled or when it get overwritten by a backup job.

Doing an erase from your vendor diagnostic tool, may be the closest to getting back to "fresh out of the wrapper".  or else do a "long erase" from BE, but that takes hours.

BE showed the available

BE showed the available capcity of 390GB, O bytes used on a new tape before and after long erase.

I did a long erase from BE on the tape, and ran the job with the same poor results.

Job only wrote 265GB to the tape using 389 GB of space before asking for a new tape.

 

IF Jobs are running fine on

IF Jobs are running fine on old tapes, why do you suspect there is something wrong with the drive? Only new tapes have a problem. I ran a cleaning tape on the drive before the latest attempt with a new tape. same poor result. 265Gb of data on 389Gb of space used.

As I wrote to RFine today, tape capacity is the same before and after long erase.

Other jobs that ran after this test with an older tape compressed the data at 1.6:1 ratio, so drive and compression does work.

 

 

...what I said was check out

...what I said was check out the tapes with your drive manufacturer's diagnostic utility. If it can't do a compression test (HP Library & Tape Tools does this for example!), then it might be an issue with the drive...or the tapes.

If the native tools can't compress 2:1, it tells you something right?

That is not how your previous

That is not how your previous post reads to me.

I think I have determained that the drive is working fine, and have tried multiple vendor tapes, with the same results.

Everything points to a problem with BE, but you keep wanting to find someone else to point the finger at.

Software has a bug, and no one will take responsibilty.

Firstly, I'm not interested

Firstly, I'm not interested in a war. Secondly, none of us will take responsibility because none of us work for Symantec. We do this in our spare time, it is best effort, and not every stranger's query gets resolved. Fact.

It's simple troubleshooting...take it or leave it. If you have support, open up a case with Symantec. Let them help you resolve it if nothing that's being suggested here fits in with what you want. Once you have a solution, post back and close it off for future reference.

Thanks!

I am having the same problem

I am having the same problem that you have.  I was wondering if you ever found a solution.  I agree that it is not hardware related and that it has something to do with the software and adding new tapes to the pool.

why do you think it is

why do you think it is software related?

After working on this all

After working on this all afternoon, I do not think it is software related anymore.  I have swapped out all the hardware and updated firmware and drivers but it was still happening so I was leaning toward software.  However if I use the drive utilities to run tests, they fail on the LTO error rate test when I use new tapes.  If i use older tapes however, the test runs successfully.  I still do not have an answer but it almost seems like something has changed in the tapes.  I do not know enough about tape makup but my combination of new HP LTO 3 tapes and Quantum half height drives is failing. 

Please let us know what your

Please let us know what your hardware or media vendor says about this.