Veritas File System 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

VxFS Performance: Creating, Mounting, and Tuning File Systems
Choosing mount Command Options
Chapter 236
Combining mount Command Options
Although mount options can be combined arbitrarily, some combinations do not make sense. The following
examples provide some common and reasonable mount option combinations.
Example 1 - Desktop File System
# mount -F vxfs -o log,mincache=closesync /dev/dsk/c1t3d0 /mnt
This guarantees that when a file is closed, its data is synchronized to disk and cannot be lost. Thus, once an
application is exited and its files are closed, no data will be lost even if the system is immediately turned off.
Example 2 - Temporary File System or Restoring from Backup
# mount -F vxfs -o tmplog,convosync=delay,mincache=tmpcache \
/dev/dsk/c1t3d0 /mnt
This combination might be used for a temporary file system where performance is more important than
absolute data integrity. Any O_SYNC writes are performed as delayed writes and delayed extending writes
are not handled specially (which could result in a file that contains garbage if the system crashes at the
wrong time). Any file written 30 seconds or so before a crash may contain garbage or be missing if this
mount combination is in effect. However, such a file system will do significantly less disk writes than a log
file system, and should have significantly better performance, depending on the application.
Example 3 - Data Synchronous Writes
# mount -F vxfs -o log,convosync=dsync /dev/dsk/c1t3d0 /mnt
This combination would be used to improve the performance of applications that perform O_SYNC writes,
but only require data synchronous write semantics. Their performance can be significantly improved if the
file system is mounted using convosync=dsync without any loss of data integrity.