Compression not working

[Abdul_Ahzan]

Hi Everyone,

My Specifications

HP Single Tape Drive: 125m DDS-3
Model: HP C1537A
Capacity Support: 12GB Uncompressed / 24GB Compressed
All current drivers and firmware applied.
Using Veritas BExec drivers
Windows server 2003
Backup Exec 10.0

I have enabled compression both in the options menu and the GUI drop down menu of the devices tab.

When i select the Media i see the compression ratio as 0.000:1.

When i do a test run backup i get the following error:

Media Capacity Check
Device : HP 1
Online append capacity : 11,263
MBOnline overwrite capacity: 11,273
MBTotal append capacity : 11,263
MBTotal overwrite capacity : 11,273
MBCapacity check status : Failed
Final error: 0xe0008703 - Job failed running its test run. See logfile for details.

When run a backup no compression takes place and tape ejects after 12GB has been written.

Can anyone help with a solution.

[Thomas_Cupps]

Join the club, I ended up breaking my back up down into two seperate jobs. You can do a search for compression & see that your not alone. You may however wanna try some of the stuff suggested in those threads.

[Amruta_Bhide]

Hello Abdul,

Are you talking about Hardware or Software Compression?

Hardware compression is done by the device itself. When you use hardware compression option on Backup Exec (BE), BE commands the hardware to go ahead with the compression. However the hardware compression depends on the device. The device should support Hardware Compression. We advice you to contact your Vendor for more information of the same.

Software compression is done by BE. It is said to achivachievepression of 2:1 but that ratio is hardly ever achieved. Compression can be highly variable depending on your input data, as the software compression depends on the type of file or data you are trying to back up. For example: Already compressed files cannot be compressed any further. And the compression for normal '.ttext files will be more than the compression of '.gif' or database files.


You can refer to the following article to understand this concept better.



http://seer.support.veritas.com/docs/199542.htm

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You can also go through the following article which will help to check that the data is being properly written to the media.




http://seer.support.veritas.com/docs/246958.htm


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Thanks.

[Abdul_Ahzan]

HI,

I have been in touch with the hardware manufacturer and they have run a daignostic and compression test on the drive. The results were, compression is supported and successful.

However, when hardware compression is enabled in Veritas we still are getting no compression at all.

Our backup files include Exchange 2003 Mailboxes and the information store, word documents plus mixture other docs.

What can we do next?

Thanks....Message was edited by:
Abdul Ahzan

[Abdul_Ahzan]

HI,

Are there any other solutions to resolve this issue?


Thanks:)

[tejashree_Bhate]

Hello,

As mentioned in our previous mail compression can only be done if the device supports it. Backup Exec does not do hardware compression.Backup Exec only dispalys it in the job log.

You may try NT backup and verify results.


Note:- if we do not receive your reply within two business days, this post would be assumed answered and archived.