Each entry in tunefstab is a line of fields in one of the following formats:
block device tunefs options
system_default tunefs options
The block device is the name of the device on which the VxFS file system is mounted. If there is more than one line that specifies options for a device, each line is processed and the options are set in order.
In place of block device, system_default may be used to specify tuneables for each device to be processed. If there is an entry for both a device and system_default, the system_default value will take precedence.
Lines in tunefstab that start with the '#' character are considered comments and will be ignored.
The tunefs options correspond to the tunable parameters that vxtunefs(ADM) and mount_vxfs(ADM) will set on the file system. Each option in this list is a name=value pair. The options are comma separated. There should be no space or tab between the options, or between the option and the comma separator.
The vxtunefs(ADM) manual page describes each of the supported options.
The default tunefstab file is /etc/vx/tunefstab.
/dev/dsk/c3b0t1d0s4 read_pref_io=128k,read_nstream=4or these lines:
/dev/dsk/c3b0t1d0s4 read_pref_io=128k /dev/dsk/c3b0t1d0s4 read_nstream=4
Alternatively, if the tuneables need to be applied to all devices, the following line could be used: