[Gluster-users] GlusterFS as virtual machine storage
pavel.szalbot at gmail.com
Thu Aug 24 05:44:22 UTC 2017
On Thu, Aug 24, 2017 at 2:13 AM, WK <wkmail at bneit.com> wrote:
> The default timeout for most OS versions is 30 seconds and the Gluster
> timeout is 42, so yes you can trigger an RO event.
I get read-only mount within approximately 2 seconds after failed IO.
> Though it is easy enough to raise as Pavel mentioned
> # echo 90 > /sys/block/sda/device/timeout
AFAIK this is applicable only for directly attached block devices
> Likewise virtio "disks" don't even have a timeout value that I am aware of
> and I don't recall them being extremely sensitive to disk issues on either
> Gluster, NFS or DAS.
We use only virtio and these problems are persistent - temporarily
suspending a node (e.g. HW or Gluster upgrade, reboot) is very scary,
because we often end up with read-only filesystems on all VMs.
However we use ext4, so I cannot comment on XFS.
This discussion will probably end before I migrate VMs from Gluster to
local storage on our Openstack nodes, but I might run some tests
afterwards and keep you posted.
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