I was asked to explain how checker_timeout works for checkers like directio, that don't issue scsi commands with an explicit timeout
Signed-off-by: Benjamin Marzinski <[email protected]> --- multipath/multipath.conf.5 | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5 index ea66a01e..c7c4184b 100644 --- a/multipath/multipath.conf.5 +++ b/multipath/multipath.conf.5 @@ -639,8 +639,13 @@ The default is: \fBno\fR . .TP .B checker_timeout -Specify the timeout to use for path checkers and prioritizers that issue SCSI -commands with an explicit timeout, in seconds. +Specify the timeout to use for path checkers and prioritizers, in seconds. +Only prioritizers that issue scsi commands use checker_timeout. Checkers +that support an asynchronous mode (\fItur\fR and \fIdirectio\fR), will +return shortly after being called by multipathd, regardless of whether the +storage array responds. If the storage array hasn't responded, mulitpathd will +check for a response every second, until \fIchecker_timeout\fR seconds have +elapsed. .RS .TP The default is: in \fB/sys/block/sd<x>/device/timeout\fR -- 2.17.2 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
