To the left of the drive icon are two lines of status. The top line is the drive status (for example, empty, loading, or idle). The bottom line is the tape barcode label.
If the tape label is unlabeled, or the label is unreadable, this line will be blank.
Note: Older firmware would distinguish between unlabeled and unreadable by showing '??????' for an unreadable label. This however, caused problems with ISV software (since having more than one of these could be treated as 'duplicate' labels). Newer firmware now reports unreadable labels as unlabeled (blank).
Note: Some DLT tape labels do not meet the ANSI code 39 spec for bar thickness and spacing. The recently released 2.33 autoloader firmware included improvements for reading out-of-spec tape labels.
Regarding your question on drive compression, this is a parameter normally controlled by the host driver and/or ISV application.
You can check the drive's current compression setting by viewing a support ticket with HP Library & Tape Tools (available as downloadable software from the HP website). Under the drive device, in the 'Drive Configuration Settings' section, look at the 'Data Compression' setting.
If I'm not mistaken, the data compression setting is only valid when a tape is actually loaded in the drive.
There is also a data compression 'test' available in the test menu section of HP L&TT.
