Re: [libvirt-users] Fwd: kvm
On Mon, Apr 22, 2013 at 10:59:25AM +0100, Gary Lloyd wrote:
I was wondering if anyone could help me with an issue with KVM and
ISCSI.
If we restart a controller on our EqualLogic SAN or there are any
network interruptions on the storage network, KVM guests throw a
wobbler and their files systems go into read only(centos 5.9 guest
with virtio driver).
I have read a few forums that indicate you can set disk timeout values
on the guests themselves but this is not possible using the virtio
driver, which is what we are currently using.
Is there any way we can instruct KVM to pause the vm's if there is a
storage failure and resume them when the storage comes back online ?
We are currently running Centos 6.4. There seems to be a werror='stop'
and rerror='stop' options to achieve this but if I try to put these in
options in the libvirt xml file for a vm, libvirt appears to be
removing them.
Please email libvirt-users(a)redhat.com for questions about libvirt in the
future.
This is a question about libvirt domain XML. The documentation is here:
http://libvirt.org/formatdomain.html#elementsDisks
The attribute is called "error_policy". The documentation says:
The optional error_policy attribute controls how the hypervisor will
behave on a disk read or write error, possible values are "stop",
"report", "ignore", and "enospace".Since 0.8.0,
"report" since 0.9.7 The
default setting of error_policy is "report". There is also an optional
rerror_policy that controls behavior for read errors only. Since 0.9.7.
If no rerror_policy is given, error_policy is used for both read and
write errors. If rerror_policy is given, it overrides the error_policy
for read errors. Also note that "enospace" is not a valid policy for
read errors, so if error_policy is set to "enospace" and no
rerror_policy is given, the read error policy will be left at its
default, which is "report".
Stefan