Hello, I found a weird behaviour regarding reported friendly names comparing multipath on Debian 5.0.3 and CentOS 5.3 accessing a SAN IBM DS8300 [0] LUNs. Output snippet of both multipath -l -v3 commands: Debian: 36005076308ffc36c0000000000001107dm-5 IBM ,2107900 [size=200G][features=1 queue_if_no_path][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 2:0:0:5 sdg 8:96 [active][undef] \_ 2:0:1:5 sdq 65:0 [active][undef] \_ 0:0:0:5 sdaa 65:160 [active][undef] \_ 0:0:1:5 sdak 66:64 [active][undef]
CentOS: 36005076308ffc36c0000000000001107 dm-0 IBM,2107900 [size=200G][features=1 queue_if_no_path][hwhandler=0][rw] \_ round-robin 0 [prio=0][active] \_ 1:0:0:5 sdaa 65:160 [active][undef] \_ 1:0:1:5 sdak 66:64 [active][undef] \_ 3:0:0:5 sdg 8:96 [active][undef] \_ 3:0:1:5 sdq 65:0 [active][undef] As you can see, the same wwid is reported as dm-5 by Debian and dm-0 by CentOS. Being listed at both machines as /dev/dm-0 (susscesfully configured lvm over them) what will happen if multipath.conf is configured following the CentOS reported dm-0 or the Debian dm-5? I "guess" that as far as vg groups and lv are created using /dev/mapper/* friendly names reported by multipath instead of direct /dev/dm-* devices, and multipath.conf configured carefully using the correct wwid, should be all right. There are some lv created at both machines already, over directly grouped /dev/dm-* devices instead of /dev/mapper/* ones. I do not have physical access to the machines, nor previous experience with these san. Any suggestions or urls to read? Thanks. Andre Felipe Machado [0] http://www-03.ibm.com/systems/storage/disk/ds8000/
