Hi Steven, Read/Write errors are recorded when an active path of the geom_multipath device is pulled while running the i/o on dataset created for the pool. Running I/o on dataset using dd. *Freebsd version :* 9.0 *Patch imported from stable 9 : *r229303, r234916 *zpool status:* * * pool: poola state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM poola ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 multipath/newdisk4 ONLINE 0 0 0 multipath/newdisk2 ONLINE 0 0 0 errors: No known data errors * * * * *gmultipath status:* * * Name Status Components multipath/newdisk2 OPTIMAL da7 (ACTIVE) da2 (PASSIVE) multipath/newdisk1 OPTIMAL da6 (ACTIVE) da1 (PASSIVE) multipath/newdisk4 OPTIMAL da3 (ACTIVE) da4 (PASSIVE) multipath/newdisk OPTIMAL da0 (ACTIVE) da5 (PASSIVE) multipath/newdisk3 OPTIMAL da8 (ACTIVE) da9 (PASSIVE) * * *zpool status after pulling the active path g_multipath device*: pool: mypool1 state: ONLINE status: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected. action: Determine if the device needs to be replaced, and clear the errors using 'zpool clear' or replace the device with 'zpool replace'. see: http://www.sun.com/msg/ZFS-8000-9P scan: resilvered 27.2M in 0h0m with 0 errors on Thu Jul 4 19:47:44 2013 config: NAME STATE READ WRITE CKSUM mypool1 ONLINE 0 0 0 mirror-0 ONLINE 0 12 0 multipath/newdisk4 ONLINE 0 27 0 multipath/newdisk2 ONLINE 0 12 0 spares multipath/newdisk AVAIL errors: No known data errors Are there any dependencies for the patch that is picked from stable 9 as mentioned above?? sorry for posting it in many areas of the forum its just to find the rite fit. -- Thanks & Regards, Sowmya L