configure dm-multipath to IBM DS4800 storage

[Nuwan Alwis]

Hi guys,
Im have to attach IBM DS4800 through Mulex FC cards to our BL460 server. I have no experiance on this. I went through multipath.conf and it says some things about IBM storage which i dont understand.
Any one done this before please help

Thanks a lot in advance.

[skt_skt]

install the relevant device-mapper-multipath rpm
configure the filter(/etc/lvm/lvm.conf)

test the fail over

[skt_skt]

see attached file

[westb]

We have a DS4800 and are using RHEL5.2 on HP blade servers. They have Qlogic FC cards.

This is what we have in /etc/multipath.conf and it works for us.

Hope this helps.

device {
vendor "IBM"
product "1815.*"
hardware_handler "1 rdac"
failback` immediate
path_checker rdac
path_grouping_policy group_by_prio
prio_callout "/sbin/mpath_prio_tpc /dev/%n"
}

[Nuwan Alwis]

Thanks a lot guys. my problem is what we have is RHEL 4.6. I read some documents about dm-multipath and on that i saw that kernel should be compile with a special driver. any idea about this?
and my other question is when we configure dm-multipath does it reduce the number of devices shown in fdisk -l output.
pls explain.
im totally new to this area.

[skt_skt]

"my other question is when we configure dm-multipath does it reduce the number of devices shown in fdisk -l output."

no;I would report something similar rather


Disk /dev/dm-14: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-14 doesn't contain a valid partition table

Disk /dev/dm-15: 268 MB, 268435456 bytes
255 heads, 63 sectors/track, 32 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-15 doesn't contain a valid partition table

"my problem is what we have is RHEL 4.6. I read some documents about dm-multipath and on that i saw that kernel should be compile with a special driver. any idea about this?"

dm-multipath is a package givenby redhat(not a third party package). So there wont be any need to do any compile the kerenl.