There is a new multipathd command, "resize map <mapname>". This command is used to cause dm-multipath to adjust to a change in the size of the underlying block storage device. Use the the following procedure, after you resize the underlying block device: # multipathd -k multipathd> del path <path-name> ok multipathd> add path <path-name> ok <repeat for each path to the device> multipathd> resize map <map name> For example: # multipath -ll mpath-resize-test (36090a018c032e4801e8e341700008039) dm-5 EQLOGIC,100E-00 [size=2.0G][features=0][hwhandler=0][rw] \_ round-robin 0 [prio=1][active] \_ 2:0:0:0 sdd 8:48 [active][ready] \_ round-robin 0 [prio=1][enabled] \_ 3:0:0:0 sdc 8:32 [active][ready] # multipathd -k multipathd> del path sdc ok multipathd> add path sdc ok multipathd> del path sdd ok multipathd> add path sdd ok multipathd> resize map mpath-resize-test ok There is one restriction on the use of the device mapper multipath resize command. You can not resize a device-mapper device while there commands queued to that device. That is, do not use the resize command when no_path_retry is set to "queue", and there are no active paths to the device.