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

94 Chapter5
Performance and Tuning
Choosing an Intent Log Size
Choosing an Intent Log Size
The intent log size is chosen when a file system is created and cannot be
subsequently changed. The mkfs utility uses a default intent log size of
1024 blocks. The default size is sufficient for most workloads. If the
system is used as an NFS server or for intensive synchronous write
workloads, performance may be improved using a larger log size.
With larger intent log sizes, recovery time is proportionately longer and
the file system may consume more system resources (such as memory)
during normal operation.
There are several system performance benchmark suites for which VxFS
performs better with larger log sizes. As with block sizes, the best way to
pick the log size is to try representative system loads against various
sizes and pick the fastest.