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