Using LTO2 but can not fully untilize 400GB tape

[Shiu_Fung_Cheun]

Hello, I am using Win2003 Server + Backupexec9.1 with HP Storageworks 1/8 autoloader. And using HP Ultrium 400GB tape. When I trying to backup file from severals server, I found that when it reach to 270-280GB, it require me to insert a new blank media. Where is 130GB go? THe compression rate is not acceptable, is it normal? Or I need to made some change in backupexec or tape drive? Thanks.

[Ken_Putnam]

Those "400GB" tapes are actually ratred at 200/400, right?

2:1 compression is a marketing dream rather than an engineering promise. I generally figure about 1.3:1, so if you are getting 270-280GB, you are right in the ball park

See also http://seer.support.veritas.com/docs/199542.htm

[Shyam_Sundar]

Hello,

As per the other post, double the size of the native capacity is unacheivable. Normally, backup compression of 1.5 :1 or slightly less than that is the best compression that can be achieved under normal conditions as there are various other factors that affect compression including environmental.

Also please refer to the document 199542 which is also mentioned in the other post.


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