Обсуждение: Using rsync for base backups for PITR
I'm reading conflicting information on this. Is this a supported technique? start_backup rsync the initial base backup stop_backup Then, periodically, start_backup rsync again stop_backup It's my opinion that this wouuld significantly cut down the 30GB base backup I'll need to take for each PITR.
Scott Whitney wrote: > I'm reading conflicting information on this. Is this a supported technique? > > start_backup > rsync the initial base backup > stop_backup > > Then, periodically, > start_backup > rsync again > stop_backup > > It's my opinion that this wouuld significantly cut down the 30GB base backup > I'll need to take for each PITR. Uh, well, yes, that will work, but you don't have a valid archive _while_ the rsync is happening. I think that would be a problem if there was a failure during the rsync update. -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
In the same way that you don't have a valid archive while the tar is running, no? In either case, I have to archive the WAL segments used during the file system backup, right? Is rsync a supported method for a warm standby server? Specifically, I'm thinking about: http://www.taygeta.com/ha-postgresql.html -----Original Message----- From: Bruce Momjian [mailto:bruce@momjian.us] Sent: Oct 10, 2007 11:39 AM To: Scott Whitney Cc: pgsql-admin@postgresql.org Subject: Re: [ADMIN] Using rsync for base backups for PITR Scott Whitney wrote: > I'm reading conflicting information on this. Is this a supported technique? > > start_backup > rsync the initial base backup > stop_backup > > Then, periodically, > start_backup > rsync again > stop_backup > > It's my opinion that this wouuld significantly cut down the 30GB base backup > I'll need to take for each PITR. Uh, well, yes, that will work, but you don't have a valid archive _while_ the rsync is happening. I think that would be a problem if there was a failure during the rsync update. -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
Scott Whitney wrote: > In the same way that you don't have a valid archive while the tar is > running, no? In either case, I have to archive the WAL segments used during > the file system backup, right? Well, with the tar I assume you still have the old tar around. This is not true with the rsync update you suggested. > Is rsync a supported method for a warm standby server? Specifically, I'm > thinking about: > http://www.taygeta.com/ha-postgresql.html Well, the standby is fine while the rsync is not runing, but while syncing that backup has an inconsistent view of the database. PITR works only because the PITR logs fix up any consistencies. The rsync is not the same as a file system snapshot. -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
On Wed, 2007-10-10 at 11:46 -0500, Scott Whitney wrote: > Is rsync a supported method for a warm standby server? Specifically, I'm > thinking about: > http://www.taygeta.com/ha-postgresql.html That's dated 2001... -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com