Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Planning a Workgroup
Planning to Manage File Systems
Chapter 296
Additionally, the system administrator can control the way writes are
handled, with and without O_SYNC.
• the mincache mount option determines how ordinary writes are
treated.
• the convosync option determines how synchronous writes are
treated
Given all the many JFS options, what are some useful combinations of
logging and caching?
mount -o log,mincache=dsync
• provides full integrity for metadata and user data
• logs all transactions immediately
• treats all writes as synchronous
mount -o log
• provides full integrity for metadata
• logs all transactions immediately
• normal UNIX semantics apply to writes
— Flushed periodically by syncer (1M) daemon.
— Can be flushed explicitly by sync (1M)
mount -o delaylog
• provides full integrity for critical metadata
• logs critical metadata changes immediately
• delays logging of non-critical metadata changes
— Most common operation: updating file access or modification
time
• normal UNIX semantics apply to writes
mount -o nolog,convosync=delay
• provides maximum performance, but minimum protection
• does not log any transactions