mount_vxfs(1M)

Clear all data extents before allocating them to a file (requires synchronous zeroing, on disk, of certain newly allocated extents). This prevents uninitialized data from being written to a file at the time of a system crash.

Alter the caching behavior of the file system for O_SYNC and O_DSYNC I/O operations.

The direct value handles any reads or writes with the O_SYNC or O_DSYNC flag as if the VX_DIRECT caching advisory is set.

The dsync value handles any writes with the O_SYNC flag as if the VX_DSYNC caching advisory is set. It does not modify behavior for writes with O_DSYNC set.

The unbuffered value handles any reads or writes with the O_SYNC or O_DSYNC flag as if the VX_UNBUFFERED caching advisory is set.

The closesync value delays O_SYNC or O_DSYNC writes so that they do not take effect immediately.

The closesync, dsync, direct, and unbuffered values all run the equivalent of an fsync(2) to be run when any file accessed with the O_SYNC or O_DSYNC flag is closed.

The delay value delays O_SYNC or O_DSYNC writes so that they do not take effect immediately. With this option, VxFS changes O_SYNC or O_DSYNC writes into delayed writes. No special action is performed when closing a file. This option effectively cancels data integrity guarantees normally provided by opening a file with O_SYNC or O_DSYNC.

NOTE: The convosync option is available only with the HP OnLineJFS product.

Generally, VxFS does O_SYNC or O_DSYNC writes by logging the data and the time change to the inode (datainlog). If the nodatainlog option is used, the logging of synchronous writes is disabled; O_SYNC writes the data into the file and updates the inode synchronously before returning to the user.

NOTE: The datainlog option is available only with the HP OnLineJFS product.

These options do not turn largefiles capability on and off (use mkfs_vxfs or fsadm_vxfs to set and clear the largefiles flag), but they do verify whether a file system is largefiles capable. If nolargefiles is specified and the mount succeeds, then the file system does not contain any files whose size is two 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 two gigabytes or larger, and large files can be created. For a mount to succeed, the option must match the largefiles flag as specified by mkfs_vxfs or fsadm_vxfs.

NOTE: Large files are supported on HP-UX 10.20 systems and above. Be careful when enabling large file system capability. System administration utilities such as backup may experience problems if they are not large-file aware.

Control intent logging. To maintain file system integrity after a system failure, logging must 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) completes logged operations that did not complete.

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.

nolog is an alias for tmplog.

Alter the caching behavior of the file system.

The direct value handles any reads without the O_SYNC flag, or any writes without the O_SYNC flag, VX_DSYNC, VX_DIRECT, and VX_UNBUFFERED caching advisories, as if the VX_DIRECT caching advisory was set.

The dsync value handles any writes without the O_SYNC flag or one of the VX_DIRECT, VX_DSYNC, or VX_UNBUFFERED caching advisories as if the VX_DSYNC caching advisory was set.

The unbuffered value handles any reads without the O_SYNC flag, or any writes without the O_SYNC flag, VX_DSYNC, VX_DIRECT, and VX_UNBUFFERED caching advisories, as if the VX_UNBUFFERED caching advisory was set.

The closesync, dsync, unbuffered, and direct values all cause the equivalent of an fsync(2) to be run when the file is closed.

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. See vxfsio(7) for an explanation of VX_DIRECT, VX_DSYNC, and VX_UNBUFFERED.

NOTE: mincache=direct, mincache=dsync, mincache=unbuffered, and mincache=tmpcache are available only with the HP OnLineJFS product.

Enable disk quotas (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 a while.

Change the mount options for a mounted file system. In particular, remount changes the logging and caching policies. It also changes a files system from read-only to read/write.

remount cannot change a file system from read/write to read-only, nor can it set the snapof or snapsize attributes.

Read/write or read-only. The default is rw.

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.

NOTE: snapof=filesystem is available only with the HP OnLineJFS product.

Used in conjunction with snapof. size 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 defaults to the entire device if not specified.

NOTE: snapsize=size is available only with the HP OnLineJFS product.

setuid execution allowed or setuid execution not allowed. The default is suid.