Re: The OS Command for pg_hotbackup -- Use lvmsnapshot instead of tar cvzf

Arnold, Sandra wrote:
> I am currently using the pg_hotbackup Perl script to backup my
> production PostgreSQL database. However, the next production database
> is going to be close to a terrabyte in size. We feel that a tar cvzf
> command is not the correct OS backup solution to use. Instead we
> would like to use lvmsnapshot. Is anyone using the pg_hotbackup
> script but instead of the tar cvzf OS command are they using lvmsnapshot?
I believe that if you take an LVM snapshot and the change size exceeds
the snapshot size (a configurable value) then the snapshot gets
released, so you might want to be careful with this solution (I don't
know how much data you accumulate, or how fast you accumulate it, or if
that rate changes, etc.). You'll also need to ensure that you snapshot
any and all tablespaces (if you use pg_start_backup() first the
snapshots need not be simultaneous, but they still must be done).

You might consider using rsync instead, it should be a lot faster than
tar, and doesn't have the same downside as using snapshots. You'll also
find that it is fairly widely used in the PostgreSQL community.

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Chander Ganesan
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