Disaster Recovery and Rsync (was [lug] Commercial rsync service?)
jbs at quiotix.com
Sat Feb 4 13:24:02 MST 2006
On Feb 3, 2006, at 23:34 , Nate Duehr wrote:
>> One way do deal with this is to use LVM snapshots. Snapshot,
>> mount snapshot read only, rsync from snapshot, unmount and then
>> delete the snapshot.
> This is very common in the commercial world. There's another step
> Put DB in quiet mode. (No disk reads or writes, but DB is still up.)
> Put DB back in normal mode.
This isn't strictly necessary, but I guess it avoids a recovery step
and the possibility of data loss due to bugs in the database and/or
storage subsystem. Ordinarily just creating a point-in-time snapshot
should be sufficient, with database rollback/recovery doing
everything else required. The snapshot looks like the system
suffered from a crash at that instant, which a decent database should
be a able to deal with.
Be careful with non-transactional databases though (such as MySQL
with non-transactional table types).
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