RHEV storage domains inaccessible and hosts non operational due to external storage failure

Issue

• Host became Non-Operational.

• The Event Log in the RHEV Admin Portal showed;

Host host-A cannot access the Storage Domain(s) <UNKNOWN> attached to the Data Center [xxx]. Setting Host state to Non-Operational.

• After a reboot, the host stayed in a Connecting state;

Host host-A is not responding. It will stay in Connecting state for a grace period of 63 seconds and after that an attempt to fence the host will be issued.

• High latency warnings were reported;

Storage domain sd-A experienced a high latency of 31.8852 seconds from host host-A. This may cause performance and functional issues. Please consult your Storage Administrator.

• The command multipath -ll hung when executed on the host.

• The vgs command was also hung in D-state.

• LVM commands displayed no Volume Groups.

• ISCSI storage domains were configured on the external storage. The targets were visible.