How can I set data compression in Solaris 9?
We have a SunFire V480 server running Solaris 9 (36GB HD) that has a external HP SureStore DAT tape drive attached. The tape drive is DDS4; native 20GB capacity with 40GB compressed. We have exceeded the 20GB capacity.
How can I set the data compression so I will be able to use all of the tape drive capacity?
I was told to change "/dev/rmt/1n" (1n is what we use now) to "/dev/rmt/1un" (ultra) but that did not work.
Your help will be greatly appreciated!
How can I set the data compression so I will be able to use all of the tape drive capacity?
I was told to change "/dev/rmt/1n" (1n is what we use now) to "/dev/rmt/1un" (ultra) but that did not work.
Your help will be greatly appreciated!
ASKER CERTIFIED SOLUTION
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if you tape driver support compress (hardware compress) than you can use /dev/rmt/1nc as the above comments.
if you don't have a tape device with that capability you can, use "usfdump + compress + dd" to do the backup :
eg:
ufsdump 0f - /fs | compress | dd of=/dev/rmt/1n obs=20480
And the corresponding rstores would look like:
dd if=/dev/rmt/1n | compress -d | ufsrestore -
Or
use GNU tar with -z (compess option) to do the job, you can download GUN tar from:
http://www.sunfreeware.com/
use GNU tar:
If you used Gnu tar to back up whatever in mydir the with something like:
cd /path-to/mydir
tar cvzf /dev/rmt/1n .
then you would restore the data with:
cd /path-to/mydir
tar xvzpf /dev/rmt/1n
if you don't have a tape device with that capability you can, use "usfdump + compress + dd" to do the backup :
eg:
ufsdump 0f - /fs | compress | dd of=/dev/rmt/1n obs=20480
And the corresponding rstores would look like:
dd if=/dev/rmt/1n | compress -d | ufsrestore -
Or
use GNU tar with -z (compess option) to do the job, you can download GUN tar from:
http://www.sunfreeware.com/
use GNU tar:
If you used Gnu tar to back up whatever in mydir the with something like:
cd /path-to/mydir
tar cvzf /dev/rmt/1n .
then you would restore the data with:
cd /path-to/mydir
tar xvzpf /dev/rmt/1n
The /dev/rmt/1cbn device should do the job, but if you require any compressed files to be made smaller, I'd suggest getting a copy of gzip from www.sunfreeware.com and using that to compress your files. HTH.
ASKER
soupdragon,
dev/rmt/1cbn worked! BTW, we are using ufsdump to do our backups. What does the "b" stand for and will I have to decompress files when I do a restore (ufsrestore)?
Thanks!
dev/rmt/1cbn worked! BTW, we are using ufsdump to do our backups. What does the "b" stand for and will I have to decompress files when I do a restore (ufsrestore)?
Thanks!
b stands for Berkeley-style device, leaving it off reverts to At&T-style as explained here:
When a file open for reading only is closed and the no-rewind bit is not set, the tape is rewound. If the no-rewind bit is set, the behavior depends on the style mode. For AT&T-style devices, the tape is positioned after the EOF following the data just read. For Berkeley-style devices, the tape is not repositioned in any way.
You can leave the b off and it should still work. Some backup systems, like Legato, require the b option since they use record rather than file level repositioning.
Under normal circumstances the two modes seem pretty interchangable unless the application specifies otherwise.
SD
When a file open for reading only is closed and the no-rewind bit is not set, the tape is rewound. If the no-rewind bit is set, the behavior depends on the style mode. For AT&T-style devices, the tape is positioned after the EOF following the data just read. For Berkeley-style devices, the tape is not repositioned in any way.
You can leave the b off and it should still work. Some backup systems, like Legato, require the b option since they use record rather than file level repositioning.
Under normal circumstances the two modes seem pretty interchangable unless the application specifies otherwise.
SD
n = not rewint
c = compression