Managing Serviceguard NFS for Linux, March 2009

statd/sm-notify on Linux does not deal with multi-homed hosts. It does not support
multiple IP addresses in sending server reboot notification.
• Multiple Package IPs are not supported with NFS
A Serviceguard package can support multiple relocatable IP addresses associated with it.
But, if lock migration feature is enabled then only one IP should be specified for NFS in the
package control script as the NFS server reboot/failover notification can be sent using only
one relocatable IP.
• NFS Defect
The NFS File Lock Migration feature is only supported in SLES 9 SP 1 (and later), and Red
Hat 4 Update 4 (and later). This is due to a defect in NFS, the file lock migration feature does
not work on base SLES9, RH4 U1, RH4 U2 and RH4 U3.
• Do not use NFS Server as an NFS Client
During package halt, SIGKILL signal is sent to the lockd kernel thread to release file locks
so that the filesystem can be unmounted successfully. If the server is also an NFS client, it
loses the NFS file locks obtained by client-side processes when SIGKILL signal is sent to the
lockd kernel thread with an intention to release server side locks. So, if the client applications
use NFS file locking, it is suggested not to use the clustered nodes configured for the NFS
package as an NFS client for any server.
• SERVICE_FAIL_FAST_ENABLED should be set to “YES”
SERVICE_FAIL_FAST_ENABLED should be set to “YES” for the NFS monitoring service in
order to have lock migration feature work consistently. (See the “Configuring Lock Migration
Feature” section in Chapter 2 for more details)
Supported Configurations
Serviceguard NFS supports the following configurations and are illustrated in the following
sections:
• Simple failover from an active NFS server node to an idle NFS server node.
• Failover from one active NFS server node to another active NFS server node, where the
adoptive node supports more than one NFS package after the failover.
• A host configured as an adoptive node for more than one NFS package. The host may also
be prevented from adopting more than one failed package at a time.
• Cascading failover, where a package may have up to several adoptive nodes.
Failover to an Idle Node
Figure 1-1 shows a simple failover from an active NFS server node to an idle NFS server node.
Supported Configurations 9