RFC: GEOM MULTIPATH rewrite
mav at FreeBSD.org
Fri Jan 20 11:15:47 UTC 2012
On 01/20/12 10:09, Nikolay Denev wrote:
> Another thing I've observed is that active/active probably only makes sense if you are accessing single LUN.
> In my tests where I have 24 LUNS that form 4 vdevs in a single zpool, the highest performance was achieved
> when I split the active paths among the controllers installed in the server importing the pool. (basically "gmultipath rotate $LUN" in rc.local for half of the paths)
> Using active/active in this situation resulted in fluctuating performance.
How big was fluctuation? Between speed of one and all paths?
Several active/active devices without knowledge about each other with
some probability will send part of requests via the same links, while
ZFS itself already does some balancing between vdevs.
More information about the freebsd-geom