mount_vxfs(1M)

Read-write (default).

Read-only.

Set-user-ID execution allowed (default).

Set-user-ID execution not allowed.

Disk quotas enabled (valid only for rw type file systems). VxFS maintains quota information in a private area of the file system. If the file system is mounted with quotas enabled, and the file system was previously mounted with quotas disabled and was modified, then the quota information is rebuilt. This may take awhile.

Changes the mount options for a mounted file system, such as logging and caching policies or whether the file system can be written to.

Controls intent logging. File system integrity across system failure requires that logging be enabled. The default is log. In log mode, file system structural changes are logged to disk before the system call returns to the application. If the system crashes, fsck_vxfs(1M) will complete logged operations that have not completed.

In delaylog mode, some system calls return before the intent log is written. This improves the performance of the system, but some changes are not guaranteed until a short time later when the intent log is written. This mode approximates traditional UNIX system guarantees for correctness in case of system failures.

In tmplog mode, the intent log is almost always delayed. This improves performance, but recent changes may disappear if the system crashes. This mode is only recommended for temporary file systems.

In nolog mode, the intent log is disabled. The other three logging modes provide fast file system recovery; nolog does not provide fast file system recovery. With nolog mode, a full structural check must be performed after a crash; this may result in loss of substantial portions of the file system, depending upon activity at the time of the crash. Usually, a nolog file system should be rebuilt with mkfs_vxfs(1M) after a crash. The nolog mode should only be used for memory resident or very temporary file systems.

Ensure that all data extents are cleared before being allocated to a file (requires synchronous zeroing, on disk, of certain newly allocated extents). This prevents uninitialized data from appearing in a file being written at the time of a system crash.

Mount the file system as a snapshot of filesystem, where filesystem is either the directory on which a VxFS file system is mounted, or is the block special file containing a mounted VxFS file system. An explicit -F vxfs option is required to mount a snapshot file system.

Used in conjunction with snapof. blocks is the size in sectors of the snapshot file system being mounted. This option is required only when the device driver is incapable of determining the size of special, and will default to the entire device if not specified.

This option is used to alter the caching behavior of the file system.

The direct value causes any writes without the O_SYNC flag and all reads to be handled as if the VX_DIRECT caching advisory was set instead.

The dsync value causes any writes without either the O_SYNC flag or the VX_DIRECT caching advisory to be handled as if the VX_DSYNC caching advisory has been set.

The closesync, dsync and direct values all cause the equivalent of an fsync(2) to be run when the file is closed. See vxfsio(7) for an explanation of VX_DIRECT and VX_DSYNC.

The tmpcache value disables delayed extending writes, trading off integrity for performance. When this option is chosen, VxFS does not zero out new extents allocated as files are sequentially written. Uninitialized data may appear in files being written at the time of a system crash.

This option is used to alter the caching behavior of the file system for O_SYNC I/O operations.

The direct value causes any reads or writes with the O_SYNC flag to be handled as if the VX_DIRECT caching advisory was set instead.

The dsync value causes any writes with the O_SYNC flag to be handled as if the VX_DSYNC caching advisory was set instead.

The closesync value causes O_SYNC writes to be delayed rather than to take effect immediately. The closesync, dsync, and direct values all cause the equivalent of an fsync(2) to be run when any file is accessed with the O_SYNC flag is closed.

The delay value causes O_SYNC writes to be delayed rather than to take effect immediately. Choosing this option causes VxFS to change all O_SYNC writes into delayed writes. No special action is performed when closing a file. This option effectively cancels any data integrity guarantees normally provided by opening a file with O_SYNC.

Normally, the VxFS file system performs small O_SYNC write requests and NFS write requests by logging both the data and the time change to the inode (datainlog). If the nodatainlog option is used, the logging of synchronous write data is disabled; such writes will write the data into the file and update the inode synchronously before returning to the user.

If one of these options is specified, the file system mount will fail if the largefile compatibility bit for the file system does not match the option specified. If nolargefiles is specified and the mount succeeds, then the file system does not contain any files whose size is 2 gigabytes or larger, and such files cannot be created. If largefiles is specified and the mount succeeds, then the file system may contain files whose size is 2 gigabytes or larger, and large files can be created. The default is to mount the file system according to the largefile compatibility bit (see fsadm_vxfs(1M) and mkfs_vxfs(1M).)