Cc: Martin Wilck <mwi...@suse.com> Cc: Benjamin Marzinski <bmarz...@redhat.com> Cc: Christophe Varoqui <christophe.varo...@opensvc.com> Cc: DM-DEVEL ML <dm-devel@lists.linux.dev> Signed-off-by: Xose Vazquez Perez <xose.vazq...@gmail.com> --- multipath/multipath.conf.5.in | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/multipath/multipath.conf.5.in b/multipath/multipath.conf.5.in index d0f6c6ac..9884df93 100644 --- a/multipath/multipath.conf.5.in +++ b/multipath/multipath.conf.5.in @@ -197,22 +197,25 @@ kernel multipath target: .RS .TP 12 .I "round-robin 0" -Loop through every path in the path group, sending the same amount of I/O to -each. Some aspects of behavior can be controlled with the attributes: -\fIrr_min_io\fR, \fIrr_min_io_rq\fR and \fIrr_weight\fR. +Choose the path for the next bunch of I/O based on a rotational distribution, +sending \fBthe same number of I/Os\fR to each path. Some aspects of behavior can be +controlled with the attributes: \fIrr_min_io\fR, \fIrr_min_io_rq\fR and \fIrr_weight\fR. .TP .I "queue-length 0" -(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on the amount -of outstanding I/O to the path. +(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on \fBthe lowest +number of outstanding in-flight I/Os\fR to the path. .TP .I "service-time 0" -(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on the amount -of outstanding I/O to the path and its relative throughput. +(Since 2.6.31 kernel) Choose the path for the next bunch of I/O based on \fBthe +lowest total size (in bytes) of outstanding in-flight I/Os\fR to the path. If +\fIrelative_throughput\fR argument is defined for each path, it's also used to +calculate the best service time. .TP .I "historical-service-time 0" -(Since 5.8 kernel) Choose the path for the next bunch of I/O based on the -estimation of future service time based on the history of previous I/O submitted -to each path. +(Since 5.8 kernel) Choose the path for the next bunch of I/O with \fBa dinamyc +algorithm based on the historical service time and the number outstanding +in-flight I/Os\fR to the path. It can be tuning with \fIbase_weight\fR and +\fIthreshold_multiplier\fR arguments. .TP The default is: \fBservice-time 0\fR .RE -- 2.49.0
