BE 2012 no compression
I have a problem with the compression in BE 2012 since upgrading from BE 2010.
But first some informations about the system:
Windows Server 2008 R2, BE 2012 SP1, Hotfix 189571, 180964, 194470
It's connected to an Quantum SuperLoader3 library with a HP Ultrium-4 drive (LTO-4).
Web Interface from the SuperLoader3 says compression is disabled but it doesn't offer an option to enable it.
In BE 2012 compression is enabled for the HP drive.
HP StorageWorks Library and Tape Tools test 'Data Compression test' running successfully with this result:
Read compression ratio is: 2.61:1; Write compression ratio is: 2.61:1; compressed write transfer rate = 38.71Mb/s; compressed read transfer rate = 34.29MB/s
So I think the device is working well.
Then I used tracer.exe to check what mode_select6 and mode_sense6 says.
The last mode_select6 before writing starts says 00 00 10 00 0F 0E C0 80 00 and so on. Guess it means data compression is being turned on.
But the following mode_sense6 says 0B 00 10 08 46 00 00 00 and so on. According this tech-doc http://www.symantec.com/docs/TECH50960 I have to look for previous mode_sense6 with an 0F in the 5th byte. I did so and found one befor the last mode_select6 operation. The mode_sense6 says now 13 00 10 00 0F 0E C0 80 00 and so on.
So as a summery; event 246 says mode_sense6 with 13 00 10 00 0F 0E C0 80; event 247 says mode_select6 with 00 00 10 00 0F 0E C0 80 and event 248-256 are 4x mode_sense6 with 0B 00 10 08 46 00 00 00.
For me thats confusing and I dont know what to do now.
In BE for the backup job compression "hardware (if available, otherwise none)" is set.
But now there's the second confusing part for me.
For getting the tracer.exe log I used an extra backup-job. I also run a quick delete of the used tape before starting. It contains our IT-Service folder with 41.266 files and 6.330 folders and about 22.5gb size.
Now the jobprotocoll says it backed up 41266 files in 6330 folder and processed 24.137.683.527 bytes in 15 minutes and 51 seconds with compressiontype hardware.
But after it BE says on the tape the used capacity is 43,2GB!!! And available is just 738GB from total 781GB.
It also says compressionratio is 1:1.
According to my bad math knowledge, it's more a compressionratio about 0.5:1 and not 1:1!!
So all in all, after upgrading from BE 2010 to 2012, i have to use more than twice the ammount of tapes needed in BE2010.
I hope some of you can help me to get the compression back to work as well as putting more than 781GB of files on a LTO-4 tape.