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References: <54E5385D47A89542BC678F5426799F3904961EF60F@OSTIEX01.osti.gov>
	<dcc563d11003021120u2cc0ec95ud8802126521e442c@mail.gmail.com>
Date: Tue, 2 Mar 2010 12:54:29 -0700
Message-ID: <dcc563d11003021154h7da61c9dg2aee52cf08da8f3@mail.gmail.com>
Subject: Re: The OS Command for pg_hotbackup -- Use lvmsnapshot
	instead of tar cvzf
From: Scott Marlowe <scott.marlowe@gmail.com>
To: "Arnold, Sandra" <ArnoldS@osti.gov>
Cc: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>,
	"pgsql-admin@postgresql.org" <pgsql-admin@postgresql.org>
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On Tue, Mar 2, 2010 at 12:20 PM, Scott Marlowe <scott.marlowe@gmail.com> wr=
ote:
> On Tue, Mar 2, 2010 at 8:43 AM, Arnold, Sandra <ArnoldS@osti.gov> wrote:
>> I am currently using the pg_hotbackup Perl script to backup my productio=
n
>> PostgreSQL database.=A0 However, the next production database is going t=
o be
>> close to a terrabyte in size.=A0 We feel that a tar cvzf command is not =
the
>> correct OS backup solution to use.=A0 Instead we would like to use
>> lvmsnapshot.=A0 Is anyone using the pg_hotbackup script but instead of=
=A0the tar
>> cvzf OS command are they using lvmsnapshot?
>>
>> Or, is anyone using lvmsnapshot and doing point-in-time recoveries?
>
> I do not run my databases on LVM because, at least in the past, LVM
> did not properly honor fsync / write barrier commands. =A0I don't know
> if this has since =A0been fixed. =A0 If your transaction rate on LVM is
> unnaturally higher than it should / could be, then suspect it is not
> fsyncing, and putting your data on it is putting it at risk.