tape drive compression

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srumap
Posts: 2
Joined: March 13th, 2009, 7:45 pm

tape drive compression

Post by srumap » March 20th, 2009, 10:29 pm

Hello , we use SEP Sesam 3.41 in our traninng center on Novell OES 2SP1 (SuSE ENT. LNX 10) servers with Quantum DLT VS80/160 GB tape drives. My question is . Does SESAM support tape compression? I think he don't , because compression tickbar is enabled on HARDDRIVE backup only , not for tape backup. due this feature we cannot use full capacity of the tape drive.... If exist some compression feature , please let me know how to set this paarmeter .
Thak you in advance.
Pavel

mwhite
Posts: 1
Joined: March 23rd, 2009, 5:49 pm

Re: tape drive compression

Post by mwhite » March 23rd, 2009, 6:00 pm

Yes, Sesam does support compression.

With windows clients you enable compression on the properties of the task.

For linux clients you set it here: /var/opt/sesam/var/ini/sms.ini set it to: Compresslevel=1


More details can be found on the wiki here: http://wiki.sepsoftware.com/wiki/index. ... n_settings

Hubert Schweinesbein
Posts: 2
Joined: March 8th, 2009, 9:50 am

Re: tape drive compression

Post by Hubert Schweinesbein » April 1st, 2009, 1:47 pm

Hi,

just to give some more information.
SEP sesam use always the compression of the tape drive - so the Hardware compression.
There is no own compress algorithm - if you write to a tape.

The tape tape drive compression in SEP sesam does only appear if you do a backup to disk (using a virtualt tape library (VTL)).
In this case SEP sesam will do a software compression.

Hubert

srumap
Posts: 2
Joined: March 13th, 2009, 7:45 pm

Re: tape drive compression

Post by srumap » May 14th, 2009, 9:53 pm

Hi guys thanx for tips - i have not been there a long time ( I did not hope anybody read my post....) . I tested compression settings on LINUX drivers for my QUANTUM DLT VS160 drive and without succes . I know the Sesam does§nt have a its own compression algorithm for tapes - I was searched for some communication settings with tape drive compression subsystem . Thanks for tips again i will try it.
Pavel

ossi1001
Posts: 77
Joined: May 15th, 2009, 10:41 am

Re: tape drive compression

Post by ossi1001 » March 15th, 2010, 3:26 pm

Hy,

you can identify the actual hardware compression level by executing the command:
/opt/sesam/bin/sesam/slu scan

Choose the devicename and execute:
/opt/sesam/bin/sesam/slu /dev/nst0 -s

Usually the first tape drive starts with /dev/nst0, maybe you have to adjust this command. If the devicename doesn't work, use the SCSI-ID instead, which is also visible with slu scan.

The compression is shown with the second command and it's set with
/opt/sesam/bin/sesam/slu /dev/nst0 -c 1


BR, ossi1001

wkoldewijn
Posts: 3
Joined: May 7th, 2010, 12:13 pm
Spam Stop: No
SEP sesam: Software

Re: tape drive compression

Post by wkoldewijn » May 7th, 2010, 12:52 pm

Can I also compress data to a harddisk?

I enabled compression under /var/opt/sesam/var/ini/sms.ini restarted the sesam server but the compression option did not become accessible under option 2 it is still faded

Can someone help me...

greets :)

ossi1001
Posts: 77
Joined: May 15th, 2009, 10:41 am

Re: tape drive compression

Post by ossi1001 » June 23rd, 2010, 1:50 pm

Hy,

there are different kinds of compression. You enabled the compression on the sesam server and so the client sends the data uncompressed to the server and the server compresses it. It's all the same, which backup job you are running, the server allways has to do the compression on your case.
The compression, which is faded in GUI, has nothing to do with the option in sms.ini and this option is possible with Windows machines only. This means, the client compresses the data on its own machine before sending it to the sesam server.

Greetings, ossi1001

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