On Fri, Nov 08, 2013 at 07:00:32AM -0500, Brian J. Murrell wrote:
> On RHEL 6.4 I have a number of kvms using qemu raw disks. They are all
> on a filesystem which has reached 500G (of 1TB) of usage. None of the
> qemu images are full as reported by qemu-img info. Yet my VMs are all
> pausing with:
>
> block I/O error in device 'drive-virtio-disk0': No space left on device (28)
>
> in their logs
> i.e.: # qemu-img info /var/lib/libvirt/images/mgmt1-disk0
> image: /var/lib/libvirt/images/mgmt1-disk0
> file format: raw
> virtual size: 120G (128849018880 bytes)
> disk size: 52G
>
> and:
>
> # df -h /var/lib/libvirt/images/
> Filesystem Size Used Avail Use% Mounted on
> /dev/mapper/vg_00-virt--images 1.0T 500G 473G 52% /var/lib/libvirt/images
Added linux-ext4 mailing list and more info from an IRC debugging
session with Brian:
The image file is on an ext4 file system. The QEMU userspace process is
performing a pwritev() system call that fails with ENOSPC.
The particular pwritev() that failed had ~600 iovecs covering about 2.4
MB of data. The file is opened O_DIRECT.
The VMs are all hitting ENOSPC when they write to the file system but
df(1) shows there should still be 48% (~473 GB) available.
Any ideas why writes produce ENOSPC on an ext4 file system with
sufficient space free?
Stefan
Hi,
I think that you should consider filing a ticket with your Red Hat
support for this issue to make sure it gets fixed quickly.
Thanks!
-Lukas
On Mon, 11 Nov 2013, Stefan Hajnoczi wrote:
> Date: Mon, 11 Nov 2013 10:43:29 +0100
> From: Stefan Hajnoczi <[email protected]>
> To: [email protected]
> Cc: [email protected], Brian J. Murrell <[email protected]>
> Subject: Re: VMs are pausing with ENOSPC
>
> On Fri, Nov 08, 2013 at 07:00:32AM -0500, Brian J. Murrell wrote:
> > On RHEL 6.4 I have a number of kvms using qemu raw disks. They are all
> > on a filesystem which has reached 500G (of 1TB) of usage. None of the
> > qemu images are full as reported by qemu-img info. Yet my VMs are all
> > pausing with:
> >
> > block I/O error in device 'drive-virtio-disk0': No space left on device (28)
> >
> > in their logs
> > i.e.: # qemu-img info /var/lib/libvirt/images/mgmt1-disk0
> > image: /var/lib/libvirt/images/mgmt1-disk0
> > file format: raw
> > virtual size: 120G (128849018880 bytes)
> > disk size: 52G
> >
> > and:
> >
> > # df -h /var/lib/libvirt/images/
> > Filesystem Size Used Avail Use% Mounted on
> > /dev/mapper/vg_00-virt--images 1.0T 500G 473G 52% /var/lib/libvirt/images
>
> Added linux-ext4 mailing list and more info from an IRC debugging
> session with Brian:
>
> The image file is on an ext4 file system. The QEMU userspace process is
> performing a pwritev() system call that fails with ENOSPC.
>
> The particular pwritev() that failed had ~600 iovecs covering about 2.4
> MB of data. The file is opened O_DIRECT.
>
> The VMs are all hitting ENOSPC when they write to the file system but
> df(1) shows there should still be 48% (~473 GB) available.
>
> Any ideas why writes produce ENOSPC on an ext4 file system with
> sufficient space free?
>
> Stefan
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>
On Mon 11-11-13 10:43:29, Stefan Hajnoczi wrote:
> On Fri, Nov 08, 2013 at 07:00:32AM -0500, Brian J. Murrell wrote:
> > On RHEL 6.4 I have a number of kvms using qemu raw disks. They are all
> > on a filesystem which has reached 500G (of 1TB) of usage. None of the
> > qemu images are full as reported by qemu-img info. Yet my VMs are all
> > pausing with:
> >
> > block I/O error in device 'drive-virtio-disk0': No space left on device (28)
> >
> > in their logs
> > i.e.: # qemu-img info /var/lib/libvirt/images/mgmt1-disk0
> > image: /var/lib/libvirt/images/mgmt1-disk0
> > file format: raw
> > virtual size: 120G (128849018880 bytes)
> > disk size: 52G
> >
> > and:
> >
> > # df -h /var/lib/libvirt/images/
> > Filesystem Size Used Avail Use% Mounted on
> > /dev/mapper/vg_00-virt--images 1.0T 500G 473G 52% /var/lib/libvirt/images
>
> Added linux-ext4 mailing list and more info from an IRC debugging
> session with Brian:
>
> The image file is on an ext4 file system. The QEMU userspace process is
> performing a pwritev() system call that fails with ENOSPC.
>
> The particular pwritev() that failed had ~600 iovecs covering about 2.4
> MB of data. The file is opened O_DIRECT.
>
> The VMs are all hitting ENOSPC when they write to the file system but
> df(1) shows there should still be 48% (~473 GB) available.
>
> Any ideas why writes produce ENOSPC on an ext4 file system with
> sufficient space free?
OK, likely a bug in RHEL 6.4 kernel. But since that is 2.6.32 with lots
of patches, I suggest you contact RHEL support to debug that further.
Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR