Re: TRIM support

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Montag, 4. Juli 2011 schrieb Leonidas Spyropoulos:
> On Mon, Jul 4, 2011 at 5:20 PM, Martin Steigerwald <Martin@lichtvoll.de> 
wrote:
> > Am Samstag, 2. Juli 2011 schrieben Sie:
> >> On Sat, 2011-07-02 at 19:08 +0100, Leonidas Spyropoulos wrote:
> >> > Hello,
> >> > 
> >> > I just installed an archlinux with btrfs root partition and would
> >> > like to set the correct mount properties
> >> > Following this:
> >> > https://wiki.archlinux.org/index.php/Solid_State_Drives
> >> > it says there that I should use the discard mount parameter to
> >> > enable TRIM.
> >> > 
> >> > I would like to ask by using ssd mount parameter would TRIM be
> >> > enabled? The SSD is Intel 320 Series 120Gb
> >> 
> >> No, the "ssd" mount parameter has nothing to do with TRIM.
> > 
> > [...]
> > 
> >> The discard option is not currently automatically enabled; I think
> >> there may have been some performance issues in certain cases with
> >> drives that have slow trim implementations. But feel free to give it
> >> a try.
> > 
> > As alternative use fstrim command from time to time or regularily
> > during a cron job. From what I understood it does batched discard of
> > all free blocks in a filesystem.
> > 
> > merkaba:~> time fstrim -v /
> > /: 5044342784 bytes was trimmed
> > fstrim -v /  0,00s user 0,36s system 10% cpu 3,486 total
> > 
> > merkaba:~> time fstrim -v /home
> > /home: 27062587392 bytes was trimmed
> > fstrim -v /home  0,00s user 0,92s system 20% cpu 4,512 total
> > 
> > First one is BTRFS, second one is Ext4 - and will be, until I am
> > convinced that BTRFS has a fully featured and working fsck and until
> > its experimental flag is removed.
> > 
> > fstrim is in util-linux(-ng) when its new enough.
> 
> Do I need to run fstrim command while the partition is offline or can
> it be done while mounted?

It is run on a mount point, so I think the filesystem needs to be mounted. 
They are here.

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