Regrading Backup and Mirroring

[Sathyaswarupa]

Is it possible to continue the back up process from exactly where the previous process stopped in a magnetic tape? If so how to do it?
Now I'm wasting a lot of free space in the tapes as I don't know how to utilize the free space after taking a backup.

How will one know if a running system is using a mirror disk or not? Any commands for that?

[Sivakumar TS]

Dear Sathyaswarupa,

1. run #mount -v and get the lvol name of the particular filesystem

2. run #lvdisplay -v

please check for the no of PVs used, it will be more than 1 for a mirrored lvol

and in the LE ( logical extent )details, you can find 2 sets of PE(physcial extents)s mapped to a each LEs, both would show "current"

For a non-mirrored lvol, there will be only one PE mapped to each LE.

HtH,

Siva.

[Victor BERRIDGE]

Hi,
It depends more on what utility you use to do your backup, e.g you cannot with fbackup but can append with tar...
It depends on your backup software on how it manages its tape pool...
Altough you may find a workaround I woulnd advise you to do so, with time data grows and will fill up your tapes... and organizing a working tape schedule understandable by all is already difficult enough.. How will you manage your data in that case? create a file with a tape catalog and all its different appends?...


All the best
Victor