HP SureStore E SAN Manager LUN Management Administrator's Guide

Using SAN Manager LM with the FC60 Storage Array 165
Advanced SAN
Administration
• UPM file-system partitions may cause some confusion on the RDAC hosts to which they
are assigned. In addition to the UNIX disks shown in Disk Administrator by SAN
Manager LM’s disk driver, the RDAC disk driver will cause an offline device to display
in Disk Administrator. However, this is expected and harmless behavior.
• If you have an unwanted UPM partition on an FC60 LUN, unassign the LUN, erase the
UPM partition map (page 148), and then reassign the LUN to the host. This will enable
the host to support failover of that LUN.
• When an FC60 device is assigned to a host, all of the device’s paths should be assigned
to the same host, or failover cannot occur. When assigning a device to a host that is
running RDAC, you must assign all of the device’s paths at the same time. To do this,
open the SAN Manager LM administration application, right-click one of the device
icons that represents a path to the device, and choose Select Related Devices. Once
the device paths are selected, drag them to the target host. When assigning UPM devices
to a host that is running RDAC, you must not assign the inactive path before assigning
the active path. Failure to follow this rule can result in Disk Administrator writing a
signature to the device, which will destroy data on the device, and the inability to
unassign the device except when the host is shut down.
• You cannot unassign Microsoft-partitioned devices from a host that is running RDAC
while that host is online. To unassign a Microsoft-partitioned device from a host, the
host must be shut down.
Note You must run the SAN Manager LM administration application on another host
to perform the unassign operation for FC60 LUNs.
• UPM volumes can be unassigned at any time from a host running RDAC, but the offline
disks listed in Disk Administrator will not be removed from Disk Administrator until
after the host is rebooted.