It may not have been 900G of tape exactly, but it certainly took the
time to send 900G over the connection to the tape drives. Even at
double the speed, it's still 1.5x the time for the same amount of
useable data being backed up. Flashbackup is definitely designed with
near full filesystems in mind. Some days I wish our windows systems
were built with VxFS or some other technology that would allow the
admins to grow the filesystems on demand and keep them close to full
capacity.

On 7/19/05, Ed Wilts <ewilts AT ewilts DOT org> wrote:
> On Tue, Jul 19, 2005 at 01:24:29PM -0500, Charles Ballowe wrote:
> > The problem I had with flash backups was that the backup image is the
> > size of the filesystem, not just the used size of the filesystem. The
> > place where I expected the biggest gains from it was on large windows
> > file servers. Unfortunately, these were recently migrated with plans
> > for growth and at the time of my testing, 300GB of data on a 900GB
> > filesystem - backups running at double the speed was nice, but still
> > took longer - and not worth chewing the tape for. I may switch back to
> > flashbackup if those filesystems are ever aproaching 80% full.
> 
> Why would you chew through 900GB of tape?  Most tape drives will
> compress that to nothing anyway.  If you're staging to DSSU it could be
> an issue.  I don't know if 6.0 addresses this or not.
> 
>         .../Ed
> 
> --
> Ed Wilts, Mounds View, MN, USA
> mailto:ewilts AT ewilts DOT org
> _______________________________________________
> Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
>