HP Serviceguard A.11.20 Release Notes, September 2012

• Redundant storage paths functioning properly
• Kernel parameters and driver configurations consistent across nodes
• Mount point overlaps (such that one file system is obscured when another is mounted)
• Unreachable DNS server
• Consistency of settings in .rhosts and /var/admin/inetd.sec
• Consistency across cluster of major and minor numbers device-file numbers
• Nested mount points
• Staleness of mirror copies
Cluster Verification and ccmon
The Cluster Consistency Monitor (ccmon) provides even more comprehensive verification capabilities
than those described in this section. ccmon is a separate product, available for purchase; ask your
HP Sales Representative for details.
NFS-mounted File Systems
As of Serviceguard A.11.20, you can use NFS-mounted (imported) file systems as shared storage
in packages.
The same package can mount more than one NFS-imported file system, and can use both cluster-local
shared storage and NFS imports.
The following rules and restrictions apply.
• NFS mounts are supported for modular, failover packages.
See chapter 6 of Managing Serviceguard for a discussion of types of packages.
• You can create a Multi-Node Package that uses an NFS file share, and this is useful only if
you want to create a HP Integrity Virtual Machine (HPVM) in a Serviceguard Package, where
the virtual machine itself uses a remote NFS share as backing store.
For details on how to configure NFS as a backing store for HPVM, see the HP-UX vPars and
Integrity VM V6.1 Administrator Guide at http://www.hp.com/go/virtualization-manuals
—> HP Integrity Virtual Machines and Online VM Migration.
• So that Serviceguard can ensure that all I/O from a node on which a package has failed is
flushed before the package restarts on an adoptive node, all the network switches and routers
between the NFS server and client must support a worst-case timeout, after which packets and
frames are dropped. This timeout is known as the Maximum Bridge Transit Delay (MBTD).
IMPORTANT: Find out the MBTD value for each affected router and switch from the vendors'
documentation; determine all of the possible paths; find the worst case sum of the MBTD values
on these paths; and use the resulting value to set the Serviceguard
CONFIGURED_IO_TIMEOUT_EXTENSION parameter. For instructions, see the discussion of
this parameter under “Cluster Configuration Parameters” in chapter 4 of Managing
Serviceguard.
Switches and routers that do not support MBTD value must not be used in a Serviceguard NFS
configuration. This might lead to delayed packets that in turn could lead to data corruption.
• Networking among the Serviceguard nodes must be configured in such a way that a single
failure in the network does not cause a package failure.
What’s in this Release 23