StoreEver Tape Storage
cancel
Showing results for 
Search instead for 
Did you mean: 

Compression issue

 
Highlighted
Occasional Visitor

Compression issue

Hi,
I have a issue with the compression of a HP Ultrium 232 LTO1: I use the /hc:on option in ntbackup but if I backup data over 105 Gbytes the ntbackup requires me another tape, so the compression doesn't work.

Firmware and drivers of device are the last, windows is up to date (Windows 2003 Small Business Server).

 

I I test the compression tape with HP L&TT the result is ok. Furthermore HP L&TT utility reports me that the compression is enabled (i see it also in windows device manager). The files that I want backup are mostly word files so they should be compressed easily.

 

Can you help me?

 

Thanks a lot.
Regards.

3 REPLIES 3
Highlighted
Occasional Contributor

Re: Compression issue

This may help

 

When you use NTBackup.exe to back up your data to a tape drive, hardware compression is turned off even when you turn on the hardware compression mode. This problem occurs even if the tape drive supports the hardware compression mode

 

http://support.microsoft.com/kb/827475

 

 

Highlighted
Occasional Advisor

Re: Compression issue

Actually, the Microsoft KB article says that NTBackup does allow hardware compression during write operations, but that after completion of the backup (in NTBackup), hardware compression is disabled.  Only third-part backup software attempting to use compression after it has been disabled by NTBackup is affected.

 

Moreover, I can confirm that enabling hardware compression in NTBackup does work.  When enabling compression, the write speed is doubled, but the restore speed is halved.

 

For more information, please look at my recent thread:

Slow restore speed from Ultrium 920 External SAS

Highlighted
Occasional Visitor

Re: Compression issue

Hi,

I have just read this microsoft KB but I have already this patch because it is included in the service pack 2.

 

How can I resolve?