Re: Debian 6 PPC 64bit on IBM Power7 - how to multipathing ?

[Frank Fegert <fra.nospam.nk@gmx.de>]

Hello,

On Wed, Aug 17, 2011 at 03:18:51PM +0200, Schneck Dennis CIS SDE wrote:
> is there a way to get multipath working with Debian 6 ?
> 
> If I define on both VIOS a VSCSI Device for the harddisk
> 
> I see 2 hardisks /dev/sda and /dev/sdb
> 
> What did I wrong ?

you probably need to put an configuration entry into /etc/multipath.conf
Personally i did the entries based on UUID for each disk like this:

  root@host:~> apt-get install scsitools multipath-tools
  root@host:~> /sbin/scsiinfo -l
  /dev/sda /dev/sdb
  root@host:~> /sbin/scsiinfo -s /dev/sda
  Serial Number '332136005076801918127980000000000023C04214503IBMfcp'
  root@host:~> /sbin/scsiinfo -s /dev/sdb
  Serial Number '332136005076801918127980000000000023C04214503IBMfcp'
  root@host:~> vi /etc/multipath.conf
    multipaths {
        multipath {
            wwid                    36005076801918127980000000000023C
        }
    }
  root@host:~> /sbin/multipath -F
  root@host:~> /sbin/multipath -ll
  mpath0 (36005076801918127980000000000023c) dm-0 AIX     ,VDASD
  [size=36G][features=1 queue_if_no_path][hwhandler=0]
  \_ round-robin 0 [prio=1][enabled]
   \_ 0:0:1:0 sda 8:0   [active][ready]
  \_ round-robin 0 [prio=1][active]
   \_ 1:0:1:0 sdb 8:16  [active][ready]

The only catch could be that your device names ("sda" and "sdb") match
the regex in the blacklist section of /etc/multipath.conf.

HTH & best regards,

    Frank Fegert