Occasionally Dell Compellent can freeze, all the lights stop blinking and the storage stop responding to the management IP and the controllers, The Cluster shared volumes (CSV) or the share data-store become unavailable in the virtualization , LUN’s become UN-reachable and only complete power down can revive the storage.
This could happens because BMC (baseboard management controller) IP not configured right. The watchdog timer is the mechanism that keeps track of the health of the BMC, the timer needs to be reset in order for the array to continue functioning properly. If the timer is not reset, the controller will reboot as a first attempt to recover from the issue. Sometimes the controllers do not reboot properly and hang.
The BMC IP address settings on the SC4020/2020 should be set as non-routable. If the IP addresses are routable, there is a possibility of the BMC getting into an unresponsive state. This could result in alerts for enclosure, sensors, and power supplies, up to and including an unplanned reset of the controller.
the default IP is usually 192.168.X.X netmask 255.255.255.0 set on it even though it is not a routable IP, if there is something on that subnet generating network traffic that can cause the BMC to hang which in turn brings down the controllers with it.
Workaround:
If the controller’s BMC is unresponsive, the controller will need to be reseated in the chassis to
drain power from the BMC. After the controller is finished initializing, change the IP address of
the BMC to be non-routable. The address can be found in the controller properties within the
Storage Center System Manager or Enterprise Manager. It is recommended that the BMC IP
addresses be configured to a different subnet than the management interfaces.
An example is below:
Top Controller: BMC IP address: 169.254.0.1 Subnet Mask: 255.255.255.0 BMC Gateway: 0.0.0.0 Bottom Controller: BMC IP address: 169.254.0.2 Subnet Mask: 255.255.255.0 BMC Gateway: 0.0.0.0
Note that the above recommended settings may not be ideal for your network. A full review of
the environments IP/Subnet scheme should be reviewed prior to making these changes.
CSTA – BMC IP address settings on SC4020