Choosing Mount Options for UFS Cluster File Systems
This section describes requirements and restrictions for mount options of UFS cluster file systems.
Note:
You can alternatively configure this and other types of file systems as highly available local file systems. For more information, see Enabling Highly Available Local File Systems in Planning and Administering Data Services for Oracle Solaris Cluster 4.4.Follow the guidelines in the following list of mount options to determine which mount options to use when you create your UFS cluster file systems.
-
global
-
Required. This option makes the file system globally visible to all nodes in the cluster.
-
logging
-
Required. This option enables logging.
-
forcedirectio
-
Conditional. This option is required only for cluster file systems that will host Oracle RAC RDBMS data files, log files, and control files.
-
onerror=panic
-
Required. You do not have to explicitly specify the
onerror=panic
mount option in the/etc/vfstab
file. This mount option is already the default value if no otheronerror
mount option is specified.Note:
Only theonerror=panic
mount option is supported by Oracle Solaris Cluster software. Do not use theonerror=umount
oronerror=lock
mount options. These mount options are not supported on cluster file systems for the following reasons:-
Use of the
onerror=umount
oronerror=lock
mount option might cause the cluster file system to lock or become inaccessible. This condition might occur if the cluster file system experiences file corruption. -
The
onerror=umount
oronerror=lock
mount option might cause the cluster file system to become unmountable. This condition might thereby cause applications that use the cluster file system to hang or prevent the applications from being killed.
-
-
syncdir
-
Optional. If you specify
syncdir
, you are guaranteed POSIX-compliant file system behavior for thewrite()
system call. If awrite()
succeeds, then this mount option ensures that sufficient space is on the disk.If you do not specify
syncdir
, the same behavior occurs that is seen with UFS file systems. When you do not specifysyncdir
, performance of writes that allocate disk blocks, such as when appending data to a file, can significantly improve. However, in some cases, withoutsyncdir
you would not discover an out-of-space condition (ENOSPC
) until you close a file.You see
ENOSPC
on close only during a very short time after a failover. Withsyncdir
, as with POSIX behavior, the out-of-space condition would be discovered before the close.
See the mount_ufs
(8) man page for more information about UFS mount options.