Re: Massive BTRFS performance degradation

Martin Steigerwald
2014-03-09T11:54:16Z

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Am Sonntag, 9. März 2014, 11:33:50 schrieb Hugo Mills:
> On Sun, Mar 09, 2014 at 11:23:29AM +0100, Swâmi Petaramesh wrote:
> > Le dimanche 9 mars 2014 11:01:17 vous avez écrit :
> > > This ThinkPad T520 has been with BTRFS since installation of the Debian
> > > sid system on it with Kernel 2.6.39 or even 2.6.38 (where Sandybridge
> > > graphics didn´t work so well as today yet).
> > >
> > > So that much to any FUD about BTRFS and SSDs.
> >
> >
> >
> > Wow !
> >
> >
> >
> > Thanks for this very interesting info. Would you tell me if you use any of
> > the SSD optimisation mount options: discard, ssd or ssd_spread ?
>
> I would recommend none of the three.
>
> ssd should be activated automatically on any non-rotational device.
> ssd_spread is generally slower on modern SSDs than the ssd option.
> discard is, except on the very latest hardware, a synchronous command
> (it's a limitation of the SATA standard), and therefore results in
> very very poor performance.

Thats exactly how I use it. I just fstrim the partitions from time to time.

Thanks,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7

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