Does the multipath tools provide policies for during failover as well? > -----Original Message----- > From: dm-devel-bounces@xxxxxxxxxx > [mailto:dm-devel-bounces@xxxxxxxxxx]On > Behalf Of christophe.varoqui@xxxxxxx > Sent: Wednesday, March 17, 2004 9:22 AM > To: device-mapper development; Lars Marowsky-Bree > Cc: device-mapper development > Subject: Re: [dm-devel] [ANNOUNCE] multipath-tools-0.1.4 > > > Selon Lars Marowsky-Bree <lmb@xxxxxxx>: > > > > Hi, I'm kind of unsure. What does multipath-tools now mean > for LVM2 and > > EVMS2's multipath support, given a distributors perspective? ;-) > > > > Do the multipath tools handle all multipath scenarios we > may encounter > > (or at least are supposed to), and will LVM2 and EVMS2 > stack cleanly on > > top of it? > > > the multipath-tools design is policy agnostic : > > the multipath configuration tool has 2 sets of policies : > > * paths grouping policies (drive the number and content of > priority groups) : > > * one priority group (full IO spreading) > * one priority group per path (failover, only one path > active at a time) > * one priority group by serial number (spread IO to all > paths through a > controler in a pair) > * one group for active paths, one group for failed paths > (for controlers that > disable their fallback paths) > > * UUID fetching policies (methods to get the UUID that will > be used to coalesce > paths into multipaths) > > * SCSI INQ EVPD page 0x83 : LU WWID > > the multipathd daemon has only one set of policies : methods > to determine if a > path is up or down. > > * do a SCSI TUR > * do a test IO > > policies can be added to fit every needs. > policies are selected based on the SCSI strings tuple (vendor/product) > > hope it helps, > cvaroqui > > > -- > > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel >
