Change of the default value in the kernel: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d2be537c3ba35 To query the device: sg_inq -p 0xb0 /dev/sdX | grep "[ml] transfer length:" Note: some arrays does not report any value. 3PAR: 65534 blocks RDAC: not reported Hitachi VSP: query error Cc: Martin Wilck <mwilck@xxxxxxxx> Cc: Benjamin Marzinski <bmarzins@xxxxxxxxxx> Cc: Christophe Varoqui <christophe.varoqui@xxxxxxxxxxx> Cc: DM-DEVEL ML <dm-devel@xxxxxxxxxx> Signed-off-by: Xose Vazquez Perez <xose.vazquez@xxxxxxxxx> --- multipath/multipath.conf.5 | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5 index 8ef3a747..21963813 100644 --- a/multipath/multipath.conf.5 +++ b/multipath/multipath.conf.5 @@ -1240,9 +1240,11 @@ The default is: \fB0\fR .B max_sectors_kb Sets the max_sectors_kb device parameter on all path devices and the multipath device to the specified value. +If the storage device(array, hard disk, ...) does not export the value to the +system, the kernel sets it to 512(kernel < 4.3) or 1024(kernel >= 4.3). .RS .TP -The default is: \fB<device dependent>\fR +The default is: \fB<device dependent>\fR, or kernel provided if there is no value. .RE . . -- 2.30.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
