Failed to activate ISO/EXPORT Storage Domains

Issue

• Failed to activate ISO/EXPORT Storage Domains.

• No host could become the Storage Pool Manager (SPM). Each one in turn would show Contending in the Admin Portal.

• Some of the other data domains were affected and marked as being in an Unknown state in the Admin Portal.

• Some VMs transitioned to a Paused state.

• From /var/log/ovirt-engine/engine.log on RHEV-M;

2014-07-07 03:19:10,850 ERROR [org.ovirt.engine.core.bll.storage.NFSStorageHelper] (org.ovirt.thread.pool-4-thread-5) [7a9e317] The connection with details xx.xx.xx.xx:/media/ISODomain failed because of error code 477 and error message is: problem while trying to mount target
2014-07-07 03:19:10,853 ERROR [org.ovirt.engine.core.bll.storage.ConnectStorageToVdsCommand] (org.ovirt.thread.pool-4-thread-5) [7a9e317] Transaction rolled-back for command: org.ovirt.engine.core.bll.storage.ConnectStorageToVdsCommand.

• The vdsm logs on the host(s) contained;

Thread-170579::INFO::2014-07-28 19:49:19,176::logUtils::44::dispatcher::(wrapper) Run and protect: connectStorageServer(domType=1, spUUID='00000000-0000-0000-0000-000000000000', conList=[{'connection': 'xx.xx.xx.xx:/media/ISODomain', 'iqn': '', 'portal': '', 'user': '', 'password': '******', 'id': '72fdba4f-1b55-4bb7-8e90-6384134eb766', 'port': ''}], options=None)
Thread-170579::DEBUG::2014-07-28 19:49:19,217::mount::202::Storage.Misc.excCmd::(_runcmd) '/usr/bin/sudo -n /bin/mount -t nfs -o soft,nosharecache,timeo=600,retrans=6,nfsvers=3 xx.xx.xx.xx:/media/ISODomain /rhev/data-center/mnt/xx.xx.xx.xx:_media_ISODomain' (cwd None)
Thread-170579::ERROR::2014-07-28 19:51:24,389::storageServer::209::StorageServer.MountConnection::(connect) Mount failed: (32, ';mount.nfs: Connection timed out\n')
  File "/usr/share/vdsm/storage/mount.py", line 198, in mount
  File "/usr/share/vdsm/storage/mount.py", line 214, in _runcmd
MountError: (32, ';mount.nfs: Connection timed out\n')
Thread-170579::ERROR::2014-07-28 19:51:24,396::hsm::2390::Storage.HSM::(connectStorageServer) Could not connect to storageServer
  File "/usr/share/vdsm/storage/hsm.py", line 2387, in connectStorageServer
MountError: (32, ';mount.nfs: Connection timed out\n')