Choosing Mount Options for UFS Cluster File
Systems
This section describes requirements and restrictions for mount options of the following types
of UFS cluster file systems:
Follow the guidelines in the following
list of mount options in the following list of mount
options to determine what 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 other onerror mount option is specified.
Note -
Only the
onerror=panic mount option is supported by Oracle Solaris Cluster software.
Do not use the
onerror=umount or
onerror=lock mount options.
These mount options are not supported on cluster file systems for the following reasons:
-
Use of the onerror=umount or onerror=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 or onerror=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.
A node might require rebooting to recover from these states.
- syncdir
-
Optional. If you specify syncdir, you are guaranteed POSIX-compliant file
system behavior for the write() system call. If a write()
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 specify syncdir, performance of writes that
allocate disk blocks, such as when appending data to a file, can significantly improve. However, in
some cases, without syncdir 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.
With syncdir, as with POSIX behavior, the out-of-space condition would be
discovered before the close.
See the
mount_ufs
(1M)
man page for more information about UFS mount options.
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 other
onerror mount option is specified.
Note -
Only the onerror=panic mount option is supported by Oracle Solaris Cluster software.
Do not use the onerror=umount or onerror=lock mount options.
These mount options are not supported on cluster file systems for the following reasons:
-
Use of the onerror=umount or onerror=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 or onerror=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.
A node might require rebooting to recover from these states.
|
syncdir
|
Optional
|
If you specify syncdir, you are guaranteed POSIX-compliant file system
behavior for the write() system call. If a write() 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 specify syncdir, performance of writes that
allocate disk blocks, such as when appending data to a file, can significantly improve. However, in
some cases, without syncdir 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.
With syncdir, as with POSIX behavior, the out-of-space condition would be
discovered before the close.
|
|
See the
mount_ufs
(1M)
man page for more information about UFS mount options.