Installation guide

104 Chapter 6:Network File Sharing Services
NFS services will not start unless the following NFS daemons are running: nfsd, rpc.mountd,
and rpc.statd.
• Filesystem mounts and their associated exports for clustered NFS services should not be included
in /etc/fstab or /etc/exports. Rather, for clustered NFS services, the parameters de-
scribing mounts and exports are entered via the cluadmin configuration utility.
6.1.2 Gathering NFS Service Configuration Parameters
In preparation of configuring NFS services, it is important to plan how the filesystems will be exported
and failed over. The following information is required in order to configure NFS services:
• Service Name — A name used to uniquely identify this service within the cluster.
• Preferred Member — Defines which system will be the NFS server for this service if more than
one cluster member is operational.
• Relocation Policy — whether to relocate the service to the preferred member if the preferred mem-
ber wasn’t running at the time the service was initially started. This parameter is useful as a means
of load balancing the cluster members as NFS servers by assigning half the load to each.
• IP Address — NFS clients access filesystems from an NFS server which is designated by its IP
Address (or associated hostname). In order to abstract NFS clients from knowing which specific
cluster member is the acting NFS server, the client systems should not use the cluster member’s
hostname as the IP address by which a service is mounted. Rather, clustered NFS services are
assigned floating IP addresses which are distinct from the cluster server’s IP addresses. This float-
ing IP address is then configured on whichever cluster member is actively serving the NFS export.
Following this approach, the NFS clients are only aware of the floating IP address and are un-
aware of the fact that clustered NFS server has been deployed. When entering an NFS service’s
IP address, an administrator will also be prompted to enter an associated netmask and broadcast
address. If
None (which is the default) is selected, then the assigned netmask and broadcast will
be the same as what the network interface is currently configured to.
• Mount Information — for non-clustered filesystems, the mount information is typically placed in
/etc/fstab. By contrast, clustered filesystems must not be placed in /etc/fstab. This is
necessary to ensure that only one cluster member at a time has the filesystem mounted. Failure to
do so will result in filesystem corruption and likely system crashes.
– Device special file — The mount information designates the disk’s device special file and the
directory on which the filesystem will be mounted. In the process of configuring an NFS
service, this information will be prompted for.
– Mount point directory — An NFS service can include more than one filesystem mount. In this
manner, the filesystems will be grouped together as a single failover unit.