topic Multipathing in Operating System - Linux

Multipathing

khalid rasool_2 — Mon, 10 Nov 2008 07:05:36 GMT

Hi all,
I have two ML570G4 with MSA 2000 storage.In ML570 I have two Emulex HBA. OS is RHEL 4.6 and kernel version is 2.6.9-42.ELsmp. Emulex driver which I am using is hp-lpfc-8.0.16.40-5. Problem is that I configured 4 logical drives in MSA2000 now problem is that on linux it showing 8 logical drives. question is that is secure path available for RHEL4 or is any other procedure to configure these paths or drives.

Re: Multipathing

Jeeshan — Mon, 10 Nov 2008 08:30:27 GMT

all logical drives is sourced from one logical drive.
you need to partitioned this drive.

Re: Multipathing

Steven E. Protter — Mon, 10 Nov 2008 12:04:11 GMT

Shalom,

multipath is built into the OS. If there are two paths it will be recongized.

RHEL 4.6 and kernel version is 2.6.9-42.ELsmp.

The kernel version you state does not match RHEL 4.6. This inconsistency can cause loss of functionality.

SEP

Re: Multipathing

khalid rasool_2 — Mon, 10 Nov 2008 15:57:23 GMT

Sorry, you are right we are using RHEL AS 4.4, Is multi path built in this version or I have to update this version.I also downloded Linux update 5 and Device mapper enablement kit for HP.Can you tell me the installation procedure of DM 4.0.0.
Thanks for correction......
Regards

Re: Multipathing

Jimmy Vance — Tue, 11 Nov 2008 12:50:23 GMT

Secure Path for Linux has not been actively developed for quite some time as it has been abandoned in favor of using Device Mapper MPIO. Device Mapper multipathing has improved greatly since RHEL4.4. You should get the latest update which I think is RHEL4.7.

To enable multipathing
# chkconfig multipathd on
# serivice multipathd start

The command
# multipath -l
will show you the paths recognised.

You may need to create the /etc/multipath.conf file as I'm not sure the code in RHEL4.7 understands the MSA2000. The documentation in the HP DM kit v4 shows the values for the file.

Re: Multipathing

khalid rasool_2 — Tue, 11 Nov 2008 18:11:00 GMT

Thanks for reply, I have configured multi pathing thru DM enablement kit v4.0.0 for HP.Now system is showing two devices which is as follows

/dev/mapper/mpath0
/dev/mapper/mpath1

However thanks for your help