On Wed, Sep 19, 2012 at 2:28 PM, Casper Bang <casper.b...@gmail.com> wrote:
>> Anand Jain <Anand.Jain <at> oracle.com> writes:
>>   archive-log-apply script - if you could, can you share the
>>   script itself ? or provide more details about the script.
>>   (It will help to understand the work-load in question).
>
> Our setup entails a whole bunch of scripts, but the apply script looks like 
> this
> (orion is the production environment, pandium is the shadow):
> http://pastebin.com/k4T7deap
>
> The script invokes rman passing rman_recover_database.rcs:

IIRC there were some patches post-3.0 which relates to sync. If oracle
db uses sync writes (or call sync somewhere, which it should), it
might help to re-run the test with more recent kernel. kernel-ml
repository might help.

> Ext4 starts out with a realtime to SCN ratio of about 3.4 and ends down 
> around a
> factor 2.2.
>
> ZFS starts out with a realtime to SCN ratio of about 7.5 and ends down around 
> a
> factor 4.4.

So zfsonlinux is actually faster than ext4 for that purpuse? coool !

>
> Btrfs starts out with a realtime to SCN ratio of about 2.2 and ends down 
> around
> a factor 0.8. This of course means we will never be able to catch up with
> production, as btrfs can't apply these as fast as they're created.
>
> It was even worse with btrfs on our 10xSSD server, where 20 min. of realtime
> work would end up taking some 5h to get applied (factor 0.06), obviously 
> useless
> to us.

Just wondering, did you use "discard" option by any chance? In my
experience it makes btrfs MUCH slower.

-- 
Fajar
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to