Backup Exec and Tape Compression

[Mike_Jones]

We have LTO3 tape libraries (IBM 33614LX) that have 2 LTO3 drives. I do not see anywhere to enable compression on the hardware, is it enabled by default? Also, when I look at the tapes in BE, they show 383Gb free, not 400Gb, is this normal?

[RM_Support]

I work mostly with AIT4 tape drives which are nominally 200GB but when I have a look in BE11 at the slots of the Autoloader (Devices tab), they always show as 195GB. I just assume it's the same as when you put a new 200GB Hard disk into a Windows C, by the time it's formatted Windows will tell you it's somewhat less (no experience of Linux here I'm afraid), I'm sure someone will tell me it's better  ;o)

As for compression, on our D2D2T setups, if we open the dup (i.e 2 tape) job template in the policy, under 'Settings, advanced' there is a drop down list to select 'Compression type' and we choose 'Hardware if availabale, otherwise none' and the AIT4 drives compress as expected. Not familiar with LTO so it may work a completely different way.

[Ken_Putnam]

Edit the job description, one of the choices is compression type

Hardware if availble

Software

None

Also, from the devices tab, right click the tape drive\properties, and verify that "enable hardware compression" is selected