HP JFS 3.3 and HP OnLineJFS 3.3 VERITAS File System 3.3 System Administrator's Guide

32 Chapter1
The VxFS File System
Extended mount Options
Extended mount Options
The VxFS file system supports extended mount options to specify:
• enhanced data integrity modes
• enhanced performance modes
• temporary file system modes
• improved synchronous writes
See Chapter 5 , “Performance and Tuning” and mount_vxfs(1M) for
details on the VxFS mount options.
Enhanced Data Integrity Modes
NOTE Performance trade-offs are associated with these mount options.
The HFS file system is “buffered” in the sense that resources are
allocated to files and data is written asynchronously to files. In general,
the buffering schemes provide better performance without compromising
data integrity.
If a system failure occurs during space allocation for a file, uninitialized
data or data from another file may appear in the extended file after
reboot. Data written shortly before the system failure may also be lost.
Using blkclear for Data Integrity
In environments where performance is more important than absolute
data integrity, the preceding situation is not of great concern. However,
VxFS supports environments that emphasize data integrity by providing
the mount -o blkclear option that ensures uninitialized data does not
appear in a file.
Using closesync for Data Integrity
VxFS provides the mount -o mincache=closesync option, which is
useful in desktop environments with users who are likely to shut off the
power on machines without halting them first. In closesync mode, only