File-System Logging

Logging is required for cluster file systems. Sun Cluster software supports the following logging file systems:

• Solaris UFS logging—See the mount_ufs(1M) man page for more information.

• Solstice DiskSuite trans-metadevice logging or Solaris Volume Manager transactional-volume logging—See “Creating DiskSuite Objects” in Solstice DiskSuite 4.2.1 User's Guide or “Transactional Volumes (Overview)” in Solaris Volume Manager Administration Guide for more information.

• VERITAS File System (VxFS) logging—See the mount_vxfs man page provided with VxFS software for more information.

The following table lists the logging file systems supported by each volume manager.

Table 1–4 Supported File System Logging Matrix

Volume Manager	Supported File System Logging
Solstice DiskSuite/Solaris Volume Manager	Solaris UFS logging,Solstice DiskSuite trans-metadevice logging or Solaris Volume Manager transactional-volume logging, VxFS logging
VERITAS Volume Manager	Solaris UFS logging, VxFS logging

Consider the following points when you choose between Solaris UFS logging and trans-metadevice logging.

• Transactional volumes are scheduled to be removed from the Solaris operating environment in an upcoming Solaris release. Solaris UFS logging, available since the Solaris 8 release, provides the same capabilities but superior performance, as well as lower system administration requirements and overhead.

• Solaris UFS log size – Solaris UFS logging always allocates the log using free space on the UFS file system, and depending on the size of the file system.

  • On file systems less than 1 Gbyte, the log occupies 1 Mbyte.

  • On file systems 1 Gbyte or greater, the log occupies 1 Mbyte per Gbyte on the file system, up to a maximum of 64 Mbytes.

• Log metadevice – A Solstice DiskSuite trans metadevice or Solaris Volume Manager transactional volume manages UFS logging. The logging device component of a trans metadevice or transactional volume is a metadevice or volume that you can mirror and stripe. You can create a maximum 1-Gbyte log size, although 64 Mbytes is sufficient for most file systems. The minimum log size is 1 Mbyte.