BSD dump/restore for SGI (does it handle active filesystems?)

[Ken Lalonde]

Dump doesn't skip files that change during the dump, but it is careful
about ensuring that what it writes is consistent.  If a file changes
size after the header record for it has been written, dump pads with
zero blocks or ignores the new data, so that the amount dumped agrees
with the header.  Inodes that change from directories to
non-directories (or vice versa) are skipped.

If you dump an active filesystem, there is a small risk that files
changing under dump will show up scrambled or not at all.  That's why I
always unmount the disk when using dump to move a filesystem to another
disk or to archive it.  For our routine backups, the risk is acceptable.
Taking the machines down for dumps sure isn't.  We've been doing this
for years without problems.

Ken Lalonde