tunchange Command

The tunchange command is used to update one or more tunable stanzas in a file.

The following is the syntax for the tunchange command:

tunchange -f filename ( -t stanza ( {-o parameter[=value]} | -D ) | -m filename2 )

where stanza is schedo, vmo, ioo, raso, no, or nfso.

The following is an example of how to update the pacefork parameter in the /etc/tunables/mytunable directory:

tunchange -f mytunable -t schedo -o pacefork=10

The following is an example of how to unconditionally update the pacefork parameter in the /etc/tunables/nextboot directory. This should be done with caution because no warning will be printed if a parameter of type bosboot was changed.

tunchange -f nextboot -t schedo -o pacefork=10

The following is an example of how to clear the schedo stanza in the nextboot file.

tunchange -f nextboot -t schedo -D

The following is an example of how to merge the /home/admin/schedo_conf file with the current nextboot file. If the file to merge contains multiple entries for a parameter, only the first entry will be applied. If both files contain an entry for the same tunable, the entry from the file to merge will replace the current nextboot file's value.

tunchange -f nextboot -m /home/admin/schedo_conf

The tunchange command is called by the tuning commands to implement the -p and -r flags using -f nextboot.