From: Paolo Bonzini <pbonzini@redhat.com>
To: Roman Mamedov <rm@romanrm.net>
Cc: linux-btrfs@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: Kernel 4.4.0 KVM guest on Btrfs locks up on snapshotting
Date: Wed, 20 Jan 2016 21:38:39 +0100 [thread overview]
Message-ID: <569FF04F.7080507@redhat.com> (raw)
In-Reply-To: <20160120234638.39695c15@natsu>
On 20/01/2016 19:46, Roman Mamedov wrote:
> On Wed, 20 Jan 2016 18:28:33 +0100 Paolo Bonzini
> <pbonzini@redhat.com> wrote:
>
>>>> Also, can you find the value of the "FUA" file in sysfs
>>>> (e.g. with "cat /sys/block/sda/device/scsi_disk/*/FUA")?
>>>
>>> It is 0 both in IDE and SCSI modes.
>>
>> And in the host?
>
> On the host the backing block device for the host filesystem is an
> MD RAID6, it does not have the FUA setting. For the actual sdX
> disks, it's all 0 as well.
>
> As I said this might be not KVM-specific, but rather a Btrfs-only
> related issue. That KVM with IDE doesn't show the problem, might be
> a coincidence since as you mentioned it doesn't load the disks as
> heavily.
>
> If you're interested in my reproducer outside of KVM, I started a
> new thread:
> http://permalink.gmane.org/gmane.comp.file-systems.btrfs/52369
Oh that's great. Indeed the "info status" output would have pointed
at an ENOSPC. It's definitely not KVM specific.
Paolo
next prev parent reply other threads:[~2016-01-20 20:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 22:02 Kernel 4.4.0 KVM guest on Btrfs locks up on snapshotting Roman Mamedov
2016-01-19 22:18 ` Paolo Bonzini
2016-01-19 23:03 ` Roman Mamedov
2016-01-20 8:28 ` Paolo Bonzini
2016-01-20 13:58 ` Roman Mamedov
2016-01-20 17:28 ` Paolo Bonzini
2016-01-20 18:46 ` Roman Mamedov
2016-01-20 20:38 ` Paolo Bonzini [this message]
2016-01-20 0:19 ` Liu Bo
2016-01-20 5:08 ` Roman Mamedov
2016-01-20 11:34 ` Paolo Bonzini
2016-01-20 15:08 ` Roman Mamedov
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