On 01/19/2011 10:30 PM, Malahal Naineni wrote: > The value of 1000 is good for bio based multipath. Seen 50% increase in > I/O ops by setting it to 1 in request based multipath configuration. > This patch would give poor performance for people still using the bio > based multipath! > > Is it possible to detect request based multipath and change only for > those configurations? > > diff -r e504a50b0db5 -r 91d6dae7d882 libmultipath/defaults.h > --- a/libmultipath/defaults.h Wed Jan 19 13:16:40 2011 -0800 > +++ b/libmultipath/defaults.h Wed Jan 19 13:29:52 2011 -0800 > @@ -5,7 +5,7 @@ > #define DEFAULT_ALIAS_PREFIX "mpath" > #define DEFAULT_FEATURES "0" > #define DEFAULT_HWHANDLER "0" > -#define DEFAULT_MINIO 1000 > +#define DEFAULT_MINIO 1 > #define DEFAULT_PGPOLICY FAILOVER > #define DEFAULT_FAILBACK -FAILBACK_MANUAL > #define DEFAULT_RR_WEIGHT RR_WEIGHT_NONE > Heh, that was the main reason for using request-based multipathing :-) So yes, changing the behaviour is a good idea. But we should equally be able to detect if request-based multipathing is present; maybe we can key off the version number of dm-multipath? Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
