I agree with Wido. Moreover, the file lock will cause performane degrade of VM deployment.
-Wei 2013/7/16 Wido den Hollander <[email protected]> > On 07/16/2013 12:27 AM, Marcus Sorensen wrote: > >> I'm ok with a symptom fix on our end, if the root cause is in >> Libvirt we can't do much about that. This is the sort of patch that >> tends to get pulled into the regular update cycle of the >> distributions, so unless there's more to it and it's not a good fix I >> imagine we will see it come through without having to wait for the >> next point releases. We still have to support existing users who might >> not be running the latest, though, so the symptom fix is probably ok >> as a temporary measure. >> > > I'm ok with not calling storagePoolRefresh every time we want a capacity > update, since that's also kind of I/O intensive for larger storage arrays. > > However, we should make sure we have a GOOD comment in the code about this > "fix", since that's the reason I initially removed the old code which > invoked "df". > > I'll see if I can get this libvirt patch into Ubuntu when it hits libvirt > upstream, since this bug is really annoying. > > Wido > > > >> On Mon, Jul 15, 2013 at 3:42 PM, Edison Su <[email protected]> wrote: >> >>> There is a serious issue on KVM(https://issues.apache.org/** >>> jira/browse/CLOUDSTACK-2729<https://issues.apache.org/jira/browse/CLOUDSTACK-2729>): >>> a libvirt storage pool can disappear on KVM host, it's easy to be >>> reproduced in our internal QA environment. >>> Wei found the root cause, is on the libvirt: >>> " >>> This is a libvirt issue. I created a ticket for it. >>> https://bugzilla.redhat.com/**show_bug.cgi?id=977706<https://bugzilla.redhat.com/show_bug.cgi?id=977706> >>> The patch is very simple. >>> https://www.redhat.com/**archives/libvir-list/2013-**July/msg00635.html<https://www.redhat.com/archives/libvir-list/2013-July/msg00635.html> >>> " >>> But it's also introduced by CloudStack, as cloudstack will call libvirt >>> storage pool refresh method each time when access the storage pool. The >>> code is added by commit: 2ffc9907f7b0d371737e39b7649f7a**f23026f5cf, >>> about less than one year ago. >>> >>> As Wei suggested, we can call storage pool refresh only if needed, it >>> will mitigate the issue(It's behavior I did on cloudstack pre-4.0), but >>> it's only treat the symptom, not the cause. >>> Or add a cluster wide lock, only one guy can access storage pool at one >>> time, we can add a file lock on NFS primary storage. >>> Any idea/feedback on how to fix this KVM issue? >>> >>> >>> >>> >
