pg.ddx.io  pgsql-admin@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Jim Mercer <jim@reptiles.org>
To: pgsql-admin@postgresql.org
Subject: risks of backup using filesystem snapshot/dump ?
Date: Sat, 6 Apr 2013 12:40:27 -0400
Message-ID: <20130406164027.GU24874@reptiles.org> (raw)
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-admin>

hi,

i'm running pgsql 9.1.3 (soon to be upgraded to 9.2.x) on FreeBSD 8-STABLE.

i've got a db of some 550GB that i want to backup on a daily basis, as we
have had some nasty hardware/power/other issues of late.

with dump on FreeBSD, you can specify -L, which does a filesystem level
snapshot before the dump starts, and then clears it afterwards.

i did a backup using dump on the filesystems, except for $PGDATA, followed
by a pg_dumpall.
this took 4 hours, and ate some 30GB (after compression)

i'm currently doing a dump of the filesystems, including $PGDATA.
this is looking like it will take 6-7 hours, and looks like it will take
some 40-50GB (after compression)

if i were to attempt a restore by replaying the 'pg_dumpall', i suspect that
i would be looking at many hours, and possibly hiccups requiring re-runs, etc.

i'm alot more comfortable with the idea of just restoring the filesystem
dump.

so, the question becomes, if i restore a filesystem snapshot backup, the
DB will be in a 'crashed' state.

what, if any, risks are there with regards to corruption, or the inability to
actually use the restored DB?

-- 
Jim Mercer     Reptilian Research      jim@reptiles.org    +1 416 410-5633
"He who dies with the most toys is nonetheless dead"


-- 
Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-admin



view thread (2+ messages)  latest in thread

Message-ID: <20130406164027.GU24874@reptiles.org>
Permalink:  ../20130406164027.GU24874@reptiles.org/
Also on:    postgresql.org/message-id/20130406164027.GU24874@reptiles.org

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-admin@postgresql.org
  Cc: jim@reptiles.org
  Subject: Re: risks of backup using filesystem snapshot/dump ?
  In-Reply-To: <20130406164027.GU24874@reptiles.org>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox