[dm-devel] rr_min_io vs rr_min_io_rq on 6.5

[Vaknin, Rami]

Hi,

I'm working on 6.5 running with 2.6.32-431.el6.x86_64, my multipath.conf if configured with both rr_min_io and rr_min_io_rq, running 64k 100% write load to my storage system using 8 paths over FC ("queue-length" policy).

I found [1] that rr_min_io is deprecated in favor of rr_min_io_rq, but playing with these values show that different rr_min_io_rq have no influence on performance in my env, however, different values of rr_min_io have huge influence on the average latency I get for the same iops.

Am I missing something?


[1] https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/DM_Multipath/MPIO_Overview.html

device-mapper-libs-1.02.79-8.el6.x86_64
device-mapper-event-libs-1.02.79-8.el6.x86_64
device-mapper-persistent-data-0.2.8-2.el6.x86_64
device-mapper-1.02.79-8.el6.x86_64
device-mapper-event-1.02.79-8.el6.x86_64
device-mapper-multipath-libs-0.4.9-72.el6_5.3.x86_64
device-mapper-multipath-0.4.9-72.el6_5.3.x86_64

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/dm-devel/attachments/20141021/2d8ed5cc/attachment.htm>