Re: Question about btrfs snapshot delay and rm -rf delay

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Donnerstag, 6. Dezember 2012 schrieb Marc MERLIN:
> On Wed, Dec 05, 2012 at 11:56:27PM -0500, Sylvain Alain wrote:
> > Hi everyone, I'm running btrfs since octobre 2012 and I would like to
> > understand 2 behavior that I noticed.
> > 
> > 1. When I delete a big directory, sometimes it can hang my box for 1
> > minutes or so, it seems that's the btrfs lock my SSD.
> 
> Doesn't directly answer your question, but if you don't have discard as a
> mount option, you should try that.
> 
> Which SSD do you have? Do normal big file writes succeed or hang too?
> 
> My guess right now is that you don't have discard, and your drive is doing
> very slow garbage collection. I had a Crucial C300 that did just that before
> it ate itself and my data a month later.
> Also check that your drive does not have a firmware update to remove those
> hangs.

Maybe also the drive does slow trims, but I doubt an Intel SSD 520 would
fall into that category.

In case you want to try out Sylvain, mount *without* discard option, and
run fstrim manually or by cron job from time to time.

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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