voliod - Starts, stops, and reports on Logical Storage Manager kernel I/O
/sbin/voliod [-f] set count
-f Force the kill of the last I/O daemon. Without this option, the I/O
daemons can only be reduced to one.
Sets the number of daemons to count.
The voliod utility starts, stops, or reports on Logical Storage Manager
kernel I/O daemons.
+ When invoked with no arguments, voliod prints the current number of
volume I/O daemons on the standard output.
+ When invoked with the set keyword, creates the number of daemons
specified by count. If more volume I/O daemons exist than are speci-
fied by count, then the excess daemons will be terminated. If more
than the maximum number (64) are specified, the specified number will
be silently limited to that maximum.
The number of daemons necessary for general I/O handling depends on system
load and usage. One daemon for each CPU on the system (or a minimum of two)
is generally adequate, unless volume recovery seems unusually slow.
Each I/O daemon starts in the background, creates an asynchronously running
kernel thread, and becomes a volume I/O daemon. The voliod utility does not
wait for these threads to complete.
Logical Storage Manager (LSM) automatically sets the number of I/O daemons
when the system starts, so it is usually not necessary to set or change the
number of I/O daemons with this command.
LSM I/O daemons cannot be stopped directly through the use of signals.
The number of Logical Storage Manager I/O daemons currently running can be
determined only by running voliod; I/O daemons do not appear in the list of
processes produced by the ps(1) command.
The voliod utility displays a diagnostic on the standard error and exits if
an error is encountered. If an I/O error occurs within a spawned I/O daemon
thread, then the I/O is not reflected in the exit status for voliod. Other-
wise, voliod returns a nonzero exit status on errors, as follows:
1 Usage errors. voliod displays a usage message.
2 The requested number of daemons cannot be started, and voliod
reports the number that were successfully started.
3 All other errors.
The device used to start and report on volume I/O daemon kernel
Commands: vold(8), voldctl(8)
Functions: fork(2), pthread(3)