why not keep going?

dean gaudet dean-list-rdiff-backup@arctic.org
Fri, 17 May 2002 10:24:12 -0700 (PDT)

On Fri, 17 May 2002 Robert.Weber@Colorado.EDU wrote:

> a) copy files to /tmp before doing the sig

the problem with copying is that the file can be modified even while being
copied.  the window is smaller, but it's not 0.

for large scale backups you should consider a snapshot-capable volume
manager.  i'm assuming you're on solaris, and unfortunately i think your
only choice there may be the commercial vxvm (veritas).  linux has LVM and
EVMS which can also do this.  some disk arrays are also capable of
creating snapshots.

snapshots are read-only versions of a volume at a particular instant in
time.  they require only enough disk space to keep track of the changes
since the snapshot began -- the volume manager uses copy-on-write
semantics to keep a copy of each block that's written in the master.