On 07/25/2014 03:33 PM, Benjamin Smith wrote:
> takes between 1 and 2 days, system load depending. We had to give up
> on rsync for backups in this context a while ago - we just couldn't
> get a "daily" backup more often then about 2x per week. Now we're
> using ZFS + send/receive to get daily backup times down into the "sub
> 60 minutes" range, and I'm just going to bite the bullet and
> synchronize everything at the application level over the next week.
> Was just looking for a shortcut...
Here is an evil thought. Is this possible for you do?
1) Setup a method to obtain a RW lock for updates on the original filesystem
2) Use rsync to create a gross copy of the original (yes, it will be
slightly out of phase,
but stick with me for a bit) on the new filesystem on top of LVM2
on top of a RAID1
volume to make the next step much more efficient.
3) Perform the following loop:
a) Set the updates lock on original filesystem
b) rsync a *subset* sub-directory of the original filesystem such
that you can complete it in, at worst, only a second or two
c) Rename the original directory to some safe alternative (safety
first)...
d) Put a symlink in place of the original directory pointing to the
newly synced file system sub-directory
e) Release the mutex lock
f) Repeat a-e until done
4) Switch over operations to the new filesystem
Another approach would be to leverage something like UnionFS (see
http://en.wikipedia.org/wiki/UnionFS ) to allow you to both use the
filesystem *and* automatically propagate all updates to the new volume
during the migration.
- Jerry Franz