[linux-lvm] [dm-devel] do not disable ext4 discards on first discard failure? [was: Re: dm snapshot: ignore discards issued to the snapshot-origin target]
Karel Zak
kzak at redhat.com
Thu May 5 08:33:44 UTC 2011
On Wed, May 04, 2011 at 11:16:05AM -0400, Martin K. Petersen wrote:
> >>>>> "Lukas" == Lukas Czerner <lczerner at redhat.com> writes:
>
> I got tired of poking around in sysfs to find the discard topology.
> Here's a patch against lsblk that adds a -D option to present this
> information in a human-readable form:
Applied, thanks.
> # lsblk -D
> NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
> sda 0 0B 0B 0
> └─sda1 0 0B 0B 0
> sdb 0 512B 2G 1
> └─sdb1 0 512B 2G 1
I have a question, 2.6.35 on my ThinkPad, non-SSD disk:
NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
sda 0 0B 0B 0
├─sda1 4294935040 0B 0B 0
├─sda2 4188038656 0B 0B 0
├─sda3 1346205184 0B 0B 0
├─sda4 3231165440 0B 0B 0
├─sda5 4188006400 0B 0B 0
│ └─kzak-home (dm-0) 0 0B 0B 0
└─sda6 2035725312 0B 0B 0
Does is make sense? The DISC-ALN is non-zero but DISC-GRAN is zero.
Note that cat /sys/block/sda/sda*/discard_alignment returns the same
numbers.
Karel
--
Karel Zak <kzak at redhat.com>
http://karelzak.blogspot.com
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