[CentOS] block level changes at the file system level?

Thu Jul 3 20:10:05 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Thu, Jul 3, 2014 at 2:48 PM, Lists <lists at benjamindsmith.com> wrote:
>
> On 07/03/2014 12:23 PM, Les Mikesell wrote:
>> But, since this is about postgresql, the right way is probably just to
>> set up replication and let it send the changes itself instead of doing
>> frequent dumps.
>
> Whatever we do, we need the ability to create a point-in-time history.
> We commonly use our archival dumps for audit, testing, and debugging
> purposes. I don't think PG + WAL provides this type of capability.

I think it does.  You should be able to have a base dump plus some
number of incremental logs that you can apply to get to a point in
time.   Might take longer than loading a single dump, though.

Depending on your data, you might be able to export it as tables in
sorted order for snapshots that would diff nicely, but it is painful
to develop things that break with changes in the data schema.


> So at
> the moment we're down to:
>
> A) run PG on a ZFS partition and snapshot ZFS.
> B) Keep making dumps (as now) and use lots of disk space.
> C) Cook something new and magical using diff, rdiff-backup, or related
> tools.

Disk space is cheap - and pg_dumps usually compress pretty well.   But
if you have time to experiment, I'd like to know how rdiff-backup or
backuppc4 performs.

-- 
   Les Mikesell
     lesmikesell at gmail.com