On Tue, Mar 2, 2010 at 12:20 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
> On Tue, Mar 2, 2010 at 8:43 AM, Arnold, Sandra <ArnoldS(at)osti(dot)gov> 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?
>>
>> 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. I don't know
> if this has since been fixed. 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.
From what I've read further on, it seems it's ok as long as it's on a
storage system like a battery backed RAID controller. Still, someone
on the list did some testing and LVM resulted in a reduced throughput
when on large fast RAID arrays, so do some testing before you set off
into production with LVM.