From: Paolo Bonzini <pbonzini@redhat.com>
To: Dusty Mabe <dustymabe@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] fstrim and cache=none
Date: Mon, 03 Jun 2013 08:39:16 +0200 [thread overview]
Message-ID: <51AC3A14.5020602@redhat.com> (raw)
In-Reply-To: <CAFfJ-R6H95+O5N4phuO611R20hEO6CoT27VAWwoU=6oq5jiRwA@mail.gmail.com>
Il 02/06/2013 22:21, Dusty Mabe ha scritto:
> Hi,
>
> Is it valid to have cache=none and discard=unmap together? I notice
> that when I have cache=none the fstrim operations inside of my guests
> gives me an error
What error? Can you add an extra disk and try
dd if=/dev/urandom of=/dev/sdc bs=1M count=32
sg_unmap -l0 -n64 /dev/sdc
from within the guest?
> and i get this from the sys filesystem:
>
> [root@guest ~]# cat /sys/block/sdb/queue/discard*
> 4096
> 0
> 0
This is expected. It won't change between discard=unmap and
discard=ignore, too. (Tip: Use "grep . /sys/block/sdb/queue/discard*"
so that it shows the filename).
>
>
> This wasn't very obvious to me to begin with and just wanted to see if
> this is a bug or as designed.
It should be. It may be a Linux bug, too.
Paolo
next prev parent reply other threads:[~2013-06-03 6:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-02 20:21 [Qemu-devel] fstrim and cache=none Dusty Mabe
2013-06-03 6:39 ` Paolo Bonzini [this message]
2013-06-03 21:39 ` Dusty Mabe
2013-06-04 1:02 ` Dusty Mabe
2013-06-04 6:53 ` Paolo Bonzini
2013-06-04 12:01 ` Dusty Mabe
2013-06-11 23:18 ` Dusty Mabe
2013-06-12 12:49 ` Paolo Bonzini
2013-06-27 2:56 ` Dusty Mabe
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