topic Re: enable compression. ULTRIUM 920 in StoreEver Tape Storage

enable compression. ULTRIUM 920

yojarmye — Mon, 10 Jan 2011 15:56:33 GMT

I have an Ultrium 920 (400/800 GB) installed and running on a redhat linux.
I want to enable hardware compression to copy up to 800 GB of information.
Looking for information I've found that setting:
# mt-f / dev/st0 compression
worked, but it is not, when it comes to 400 GB of info does not copy over.

Any idea how?

Thanks.

Re: enable compression. ULTRIUM 920

Marino Meloni_1 — Mon, 10 Jan 2011 16:40:42 GMT

usually compression is enabled by default on LTO drives
And the backup application is the one that may turn compression on or off during the backup.
May be you can check if that exist in your backup application or the backup command you want to use

Re: enable compression. ULTRIUM 920

yojarmye — Mon, 10 Jan 2011 16:47:21 GMT

thanks for the reply.
I use to copy to tape a script:

tar - label = "BACKUP $ DATE_INICIO" - verbose - create - absolute-names - blocking-factor = 128 - file = / dev/st0 - files-from "$ LIST">> $ LOG

Then, the compression hardware should enable it from the "tar"?, as would do this?

Re: enable compression. ULTRIUM 920

Marino Meloni_1 — Mon, 10 Jan 2011 17:06:58 GMT

ah ok, I understand you are not using any high level backup application but native Linux commands.

Usually the backup aplication can set a flag to change the compression mode using a scsi-3 mode page 0x0F command.

unfortunately I'm not a Linux guru and do not know the CLI command for that.