topic Multipathing in LINUX with Emulex HBA in BL460c in Operating System - Linux

Multipathing in LINUX with Emulex HBA in BL460c

Md. Farhan A Azam — Tue, 22 Dec 2009 15:07:23 GMT

Hi Gurus,

I've one BL460 server with Linux 5.3 OS and Emulex LPe1105-HP 4Gb FC HBA for HP c-Class BladeSystem is installed in the server.

I've allocated 1TB space from EVA-4400 to the host. And i am able to see the allocated LUN via 4 path becaue of 2 controller and 2 SAN switch.

Now i want to configure Multipathing with Emulex card driver. So that i can see 1 LUN instead of these four. Kindly suggest where i'll get the driver for Linux 5.3 and what will be the installation and configuration process.

Re: Multipathing in LINUX with Emulex HBA in BL460c

Sameer_Nirmal — Tue, 22 Dec 2009 19:47:30 GMT

Here you go

http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?swItem=co-61249-3〈=en&cc=us&idx=0&mode=4&

Re: Multipathing in LINUX with Emulex HBA in BL460c

Md. Farhan A Azam — Wed, 23 Dec 2009 05:13:32 GMT

Hi Sammer,

Thanks for your response,

But i can see in relaese note that this driver is not supported with RHEL 5.3.

I am trying to find the driver, any help on this will be appreciated.

thnx...farhan

Re: Multipathing in LINUX with Emulex HBA in BL460c

Nick W — Wed, 23 Dec 2009 13:29:52 GMT

I think that you may need to use the In-box drivers (supplied by RedHat) and switch over to using the RedHat OS-level multipathing capability (I think this is 'device mapper')
Sorry, I can't provide any specific links, but it should get you started...

Regards,
Nick

Re: Multipathing in LINUX with Emulex HBA in BL460c

Tim Nelson — Wed, 23 Dec 2009 14:57:21 GMT

Typically you only need to modify the /etc/multipath.conf file, comment out the devnode "*" in the blacklist section.

You can also add nice/alias names to the multipaths section.

run multipath -ll

You now access all devices using either /dev/mapper/nice-name or /dev/dm-#

The multipath.conf has a number of examples as does the man page.

Re: Multipathing in LINUX with Emulex HBA in BL460c

Md. Farhan A Azam — Thu, 24 Dec 2009 20:01:37 GMT

Hi Tim,

i've installed HP DeviceMapper.

[root@ms1 doc]# multipath -ll
mpath0 (3600508b4000a5d6200007000001b0000) dm-0 HP,HSV300
[size=1.0T][features=1 queue_if_no_path][hwhandler=0][rw]
\_ round-robin 0 [prio=100][active]
\_ 0:0:0:1 sda 8:0 [active][ready]
\_ 1:0:1:1 sdd 8:48 [active][ready]
\_ round-robin 0 [prio=20][enabled]
\_ 0:0:1:1 sdb 8:16 [active][ready]
\_ 1:0:0:1 sdc 8:32 [active][ready]
[root@ms1 doc]#
Disk /dev/sda: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 133674 1073736373+ 5 Extended

Disk /dev/sdb: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 1 133674 1073736373+ 5 Extended

Disk /dev/sdc: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 1 133674 1073736373+ 5 Extended

Disk /dev/sdd: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdd1 1 133674 1073736373+ 5 Extended

Disk /dev/dm-0: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/dm-0p1 1 133674 1073736373+ 5 Extended
[root@ms1 doc]#

I can see /dev/dm-0p1 but why other paths are still visible.

Re: Multipathing in LINUX with Emulex HBA in BL460c

dirk dierickx — Mon, 28 Dec 2009 09:19:22 GMT

you can blacklist the paths you do not want to see in the device mapper multipath config file.

Re: Multipathing in LINUX with Emulex HBA in BL460c

Tim Nelson — Mon, 28 Dec 2009 17:16:24 GMT

You will always see the others.

If you mulitpath to control the ios down multiple paths then use the /dev/dm-# device names to access the device(s)..

/dev/sda, /dev/sdb, /dev/sdc and /dev/sdc are all the same device down four different paths, fdisk just is not smart enough to know about it, but then again why should it.

If you filter out /dev/sda,b,c,d as previously mentioned using the blacklist option then multipath will not work as these are the exact devices that you wish to multipath.

To multipath or not to multipath. Which do you wish to do?

Re: Multipathing in LINUX with Emulex HBA in BL460c

Md. Farhan A Azam — Mon, 01 Feb 2010 05:10:24 GMT

Tahnks to all of you....