BackupExec showing less then 1 compression ratio

[Donnie_Francis]

Greetings,

I am having a problem where BE shows that my compression ratio is less then one usually about 0.5:1. I know this is actually happening as I run out of tape in my autoloder quickly. For a backup that should only take 2 or 3 tapes I am running through more then 8.

I have tried hardware AND software compression and I get the same result.

I am using a Dell 122T autoloader with an Ultium 1 drive.

[John_Chisari]

Suggest removing all references to the Tape library from the BE database and have it find them again, to do this..

1. In the BE Devices view - under robotic library - starting with the tape drive, right click on the it and choose Enable - this will Disable the device - then right click again and choose delete.
Do the same for the Robotic library.
If you have partitions setup - make sure you take a note of these before deleting - as you will need to clear the partitions first before deleting the library.
2. Restart the BE services.
3. The devices should come back the way the were before - if not, run the Device Configuration Wizard from Tools, Wizards.
4. Setup partitions again if need be.
5. Go into the backup jobs, make sure they still point to a valid device.

[Donnie_Francis]

Thanks for the advice but I have done that already actually more then once. It justed seemed the most natural thing to do.

[Sheetal_Risbood]

Hi,

What kind of files are being backed up here ?
Any databases or simple user data files ?

Do let us know the above.


NOTE : If we do not receive your intimation within two business days, this post would be assumed answered and archived.


Thanks.

[Donnie_Francis]

I have been working with Veritas and Dell (driver reseller) and no one has any concrete ideas as to what is wrong.

I did go though and totally uninstalled and reinstalled BackupExec and I still had the issue. Dell is replacing the drive as well.

To answer your question, I am backing up a vast assortment of things. Lots of user files, SQL db's, etc...

I will post my findings...

[priya_khire]

Hello,

How much compression does your device support? Have you tried with other devices and checked if you get the same result? For further information, refer to the following technote:

Title:How to determine the total bytes written to a piece of media within Backup Exec
http://support.veritas.com/docs/235307

Also are you referring to the compression ratio as displayed in the devices tab? How much does it display there?
Do update us on the above. In either ways do respond to this post.

NOTE : If we do not receive your intimation within two business days, this post would be marked ‘assumed answered’ and would be moved to the ‘answered threads’ pool.

Regards.

[Michael_McKenne]

I find the same result in BE 10. I get 0.9:1 compression with 357-359 MB/min backup. I believe the problem is not the compression of files method but how they calculate it.

My Exabyte VXA-2 is capable of 360 MB/min. I have over 600,000 files in 500+ directories. They are basing the compression ratio on 360 / (357-359) and rounding to a single digit.

So 0.9 : 1.

Do you have your BE configured properly? Do you have enough RAM and CPU power to handle the backup? Is your tape backup on its own SCSI bus separate from your hard drives or SCSI RAID arrays? If you are only getting 0.5 : 1, I would look at your tape device settings. If your device is 64K packet based, try 64K, 64K, 32, 0. for your device setting. I also recommend defragging and error checking on the drive to improve backup performance.

[Renuka_-]

Hello Donald,

1. Have you also tried upgrading the firmawre drivers.
2. Check if the device is connected to a RAID controller if yes move it to its own SCSI controller.
3. Try a backup with no compression and tally the volume on tape for the two.
4. try the backup with new tapes. Right click on the deivce in the deivce tab and check in the properties if harware compression is enabled.

NOTE : If we do not receive your intimation within two business days, this post would be marked assumed answered and would be moved to the ‘answered threads’ pool.

[Sheetal_Risbood]

As per our previous reply, marking the case as assumed answered and moving it to answered questions pool.

[Donnie_Francis]

After all was said and done and neither side could find anything wrong (Dell hardware and Veritas software) replacing the drive solved the problem. Dell swore up and down that the drive was working fine but as it now turns out it was not.

So the lesson here is a compression problem CAN be the hardware.

Thank youMessage was edited by:
Donald Francis