[Linux-cluster] Multipathing, CLVM and GFS

[Sajesh Singh]

Christine Caulfield wrote:
> Sajesh Singh wrote:
>> Centos 4.6
>> Cluster Suite
>>
>> I am currently running a 2 node GFS cluster. The storage is provided 
>> via a fiber channel connection to the SAN. Each node currently has  a 
>> single FC connection to the SAN. I would like to migrate to using 
>> dm-multipath with each node having dual fiber channel connections to 
>> the SAN. Can I assume that CLVM is aware of the /dev/dm-# devices 
>> that are used to access the multipathed devices? Are there any 
>> gotchas that are associated with installing the 
>> device-mapper-multipath software after the GFS cluster is up and 
>> running? Are there any howtos available for this type of setup?
>>
>
> clvmd works fine with dm-multipath devices. You will probably have to 
> edit /etc/lvm/lvm.conf to exclude the underlying /dev/sd devices to 
> stop it getting confused though.
>
> You won't be able to do this with GFS mounted on the local node 
> though, you'll have to umount it, setup dm-multipath, vgscan & 
> remount. You CAN leave them mounted on other nodes while you do it.
>
Christine,
             Should clvmd be restarted as well so that I can create new 
volume groups? I have device-mapper-multipath setup, but if I try to run 
pvcreate /dev/mapper/mpath1p1 the command just hangs without any errors.

Regards,

Sajesh