Hi all I'm trying to understand how dm works on a RHEL 4u4, ( and RHCS and GFS too). I have two QLC HBAs connected to a Sun Storage 3510 via a couple of SANBOX2 switches. Initially I uncommented all the entries in the configuration file to make some test and I manage to discover the three luns which where recognized correctly whit their path: [root@store1 ~]# multipath -ll 3600c0ff00000000009897a30ae0b0401 [size=369 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:1 sde 8:64 [active][ready] \_ 2:0:1:1 sdh 8:112 [active][ready] 3600c0ff00000000009897a30ae0b0400 [size=40 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:0 sdd 8:48 [active][ready] \_ 2:0:1:0 sdg 8:96 [active][ready] 3600c0ff00000000009897a5a29e3f800 [size=1091 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:0:0 sdc 8:32 [active][ready] \_ 2:0:0:0 sdf 8:80 [active][ready] Now, the problem is: 1) the default configuration should provide a failover policy, but it seems that it is actually using an active-active one 2) Any change I make to /etc/multipath.conf , the output of multipath -ll remains the same. Also tried to flush and reload, restart the daemon etc.. Always the same. 3) If even I REMOVE the configuration file and reboot the server, it keeps discovering the same paths! : [root@store1 ~]# ls /etc/multipath.conf ls: /etc/multipath.conf: No such file or directory [root@store1 ~]# multipath -ll 3600c0ff00000000009897a30ae0b0401 [size=369 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:1 sde 8:64 [active][ready] \_ 2:0:1:1 sdh 8:112 [active][ready] 3600c0ff00000000009897a30ae0b0400 [size=40 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:0 sdd 8:48 [active][ready] \_ 2:0:1:0 sdg 8:96 [active][ready] 3600c0ff00000000009897a5a29e3f800 [size=1091 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:0:0 sdc 8:32 [active][ready] \_ 2:0:0:0 sdf 8:80 [active][ready] [root@store1 ~]# multipath -v2 -F [root@store1 ~]# [root@store1 ~]# multipath -ll [root@store1 ~]# [root@store1 ~]# /etc/init.d/multipathd restart Stopping multipathd daemon: [ OK ] Starting multipathd daemon: [ OK ] [root@store1 ~]# [root@store1 ~]# multipath -v2 -ll [root@store1 ~]# multipath -v2 -d create: SSEAGATE_ST973401LSUN72G0210CB0H____________3LB0CB0H [size=68 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=1] \_ 0:0:0:0 sda 8:0 [ready] create: SSEAGATE_ST973401LSUN72G0210BTPF____________3LB0BTPF [size=68 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=1] \_ 0:0:1:0 sdb 8:16 [ready] create: 3600c0ff00000000009897a5a29e3f800 [size=1091 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:0:0 sdc 8:32 [ready] \_ 2:0:0:0 sdf 8:80 [ready] create: 3600c0ff00000000009897a30ae0b0400 [size=40 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:1:0 sdd 8:48 [ready] \_ 2:0:1:0 sdg 8:96 [ready] create: 3600c0ff00000000009897a30ae0b0401 [size=369 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:1:1 sde 8:64 [ready] \_ 2:0:1:1 sdh 8:112 [ready] [root@store1 ~]# multipath -v2 -ll [root@store1 ~]# multipath -v2 create: 3600c0ff00000000009897a5a29e3f800 [size=1091 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:0:0 sdc 8:32 [ready] \_ 2:0:0:0 sdf 8:80 [ready] create: 3600c0ff00000000009897a30ae0b0400 [size=40 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:1:0 sdd 8:48 [ready] \_ 2:0:1:0 sdg 8:96 [ready] create: 3600c0ff00000000009897a30ae0b0401 [size=369 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2] \_ 1:0:1:1 sde 8:64 [ready] \_ 2:0:1:1 sdh 8:112 [ready] [root@store1 ~]# multipath -v2 -ll 3600c0ff00000000009897a30ae0b0401 [size=369 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:1 sde 8:64 [active][ready] \_ 2:0:1:1 sdh 8:112 [active][ready] 3600c0ff00000000009897a30ae0b0400 [size=40 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:1:0 sdd 8:48 [active][ready] \_ 2:0:1:0 sdg 8:96 [active][ready] 3600c0ff00000000009897a5a29e3f800 [size=1091 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=2][active] \_ 1:0:0:0 sdc 8:32 [active][ready] \_ 2:0:0:0 sdf 8:80 [active][ready] [root@store1 ~]# How is it possible?? Thanks in advance -- Claudio Tassini