* [linux-lvm] on discards
@ 2017-05-15 3:16 Xen
2017-05-15 8:08 ` Zdenek Kabelac
0 siblings, 1 reply; 2+ messages in thread
From: Xen @ 2017-05-15 3:16 UTC (permalink / raw)
To: Linux lvm
On discards,
I have a thin pool that filled up when there was enough space, because
the filesystem hadn't issued discards.
I have ext4 mounted with the discard option, I hope, because it is in
the list of default mount options of tune2fs:
Default mount options: user_xattr acl discard
What can I do to ensure that it won't happen again?
Is the filesystem really mounted with discard?
It doesn't say so anywhere.
Regards.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [linux-lvm] on discards
2017-05-15 3:16 [linux-lvm] on discards Xen
@ 2017-05-15 8:08 ` Zdenek Kabelac
0 siblings, 0 replies; 2+ messages in thread
From: Zdenek Kabelac @ 2017-05-15 8:08 UTC (permalink / raw)
To: LVM general discussion and development, Xen
Dne 15.5.2017 v 05:16 Xen napsal(a):
> On discards,
>
> I have a thin pool that filled up when there was enough space, because the
> filesystem hadn't issued discards.
>
> I have ext4 mounted with the discard option, I hope, because it is in the list
> of default mount options of tune2fs:
>
> Default mount options: user_xattr acl discard
>
> What can I do to ensure that it won't happen again?
>
> Is the filesystem really mounted with discard?
>
> It doesn't say so anywhere.
>
Hi
I'd not suggest to mount fs with discard - but rather run 'fstrim' in your
cron once a while.
Standalone 'small trim' on deleted file is quite inefficient and will not
resolve aggregation of continuous blocks for proper trimming.
For thin-pool - min size of trim is i.e. whole 64K chunk, - when it sits on
SSD you need to even trim much multiple pool chunks to free something on your SSD.
When you run 'fstrim' whole region of unused blocks is trimmed - to it's
always biggest possible chunk.
Regards
Zdenek
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-05-15 3:16 [linux-lvm] on discards Xen
2017-05-15 8:08 ` Zdenek Kabelac
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