topic Re: dm-multipath in Operating System - Linux

dm-multipath

ossupport55 — Wed, 08 Jul 2009 06:17:33 GMT

Folks,

I need to get this out. Where could i find the "specific settings" for the Hitachi USP1100 and USPV which i should include in the multipath.conf.
The below link suggests only a few are there by default:
http://kbase.redhat.com/faq/docs/DOC-1251

Ps: Our arrays are HDS USPV and USP1100

cheers folks.

Re: dm-multipath

Steven E. Protter — Wed, 08 Jul 2009 07:20:07 GMT

Shalom,

Alternative document:
http://www.redhat.com/docs/manuals/csgfs/browse/4.6/DM_Multipath/index.html

You don't indicate your RHEL version, so I'm guessing.

There is no actual need to configure it. If there are two paths to the disk it will work active passive without modification.

To have two paths to the disk, you would need to connections (fiber or scsi) to the disk.

SEP

Re: dm-multipath

ossupport55 — Wed, 08 Jul 2009 08:33:49 GMT

Hiya,

Thanks Steven, Well my mistake couldn't quote the RHEL version. It's RHEL V5.2 and 5.3 would be tested as well.
What should i be giving :

device {
vendor "IBM"
product "S/390.*"
}

In the above block, any idea?
Thanks for the link.

cheers,

RHEL 5 out of the box with the inbox driver is stable enough for Dm-Multipath ?

cheers,

Re: dm-multipath

Bharath_Pingali — Thu, 09 Jul 2009 01:27:24 GMT

Hello ossuport55,

These setting should be given by the storage vendor and not use genric values.

The storage vendor would have tested the values.

Example for HP array;

For EVA3000/EVA5000/EVA4x00/EVA6x00/EVA8x00
device
{
vendor "(HP|COMPAQ)"
product "HSV1[01]1\(C\)COMPAQ|HSV[2][01]0|HSV300|HSV4[05]0"
path_grouping_policy group_by_prio
getuid_callout "/lib/udev/scsi_id -g -u /dev/%n"
path_checker tur
path_selector "round-robin 0"
prio alua
rr_weight uniform
failback immediate
hardware_handler "0"
no_path_retry 12
rr_min_io 100
}
6

Again on the driver, your storage vendor will have a supported driver for the OS.

Hope this info helps.

-Thank You
Bharath