On Thu, 1 May 2003 at 9:07am, Gregor Ibic wrote

> Is there some other method to pack (compress) files and store them on the
> tape, to get faster recovery
> procedure? We will switch to Ultrium2 and it would be a nightmare if 400GB
> file has to be read entirely
> just to recover a small piece.

A couple of notes:

1) The 2:1 ratio (or 2.6:1 in the case of AIT) claimed by vendors for 
   hardware compression is rather optimistic, and highly dependent on
   your data type(s).  Always work from the native capacity (200GB in
   the case of Ultrium2).

2) There won't be one 200GB file on a 200GB native tape.  There are 
   several files, each one corresponding to a disk list entry, and
   sized accordingly.

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University