Installation guide

Section 6.2:Setting Up a High Availability Samba Service 115
6.2.3 Gathering Samba Service Configuration Parameters
When preparing to configure Samba services, determine configuration information such as which
filesystems will be presented as shares to Windows based clients. The following information is re-
quired 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 Samba server for this service when more
than one cluster member is operational.
• Relocation Policy — whether to relocate the service to the preferred member if the preferred mem-
ber was not running at the time the service was initially started. This parameter is useful as a means
of load balancing the cluster members as Samba servers by assigning half the load to each.
• Status Check Interval — specifies how often (in seconds) the cluster subsystem should verify that
the pair of Samba daemons smbd/nmbd which are associated with this service are running. In the
event that either of these daemons have unexpectedly exited, they will be automatically restarted to
resume services. If a value of 0 is specified, then no monitoring will be performed. For example,
designating an interval of 90 seconds will result in monitoring at that interval.
• IP Address — Windows clients access file shares from a server as designated by its IP Address
(or associated hostname). In order to abstract Windows clients from knowing which specific clus-
ter member is the acting Samba server, the client systems should not use the cluster member’s
hostname as the IP address by which a service is accessed. Rather, clustered Samba services
are assigned floating IP addresses which are distinct from the cluster server’s IP addresses. This
floating IP address is then configured on which ever cluster member is actively serving the share.
Following this approach, the Windows clients are only aware of the floating IP address and are
unaware of the fact that clustered Samba services have been deployed. When you enter a Samba
service’s IP address, you will also be prompted to enter an associated netmask and broadcast ad-
dress. If you select the default of None, 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. In 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 a Samba
service you will be prompted for this information.
– Mount point directory — A Samba service can include more than one filesystem mount. In
this manner, the filesystems will be grouped together as a single failover unit.
– Mount options — The mount information also designates the mount options.