LUN persistence with QLogic driver

[yyghp]

LUN persistence with QLogic driver

I presented 2 LUNs on 2 different EVA5000 to a server, and used QLogic multipath driver to combine 4 paths to 1, then I can see 2 LUNs ( each LUN is at different location. ):

[root@srsA /]# lssd
sda 0,0,0,2 COMPAQ HSV110 (C)COMPAQ 3020 5000-1fe1-5004-569c
sdb 0,0,2,3 COMPAQ HSV110 (C)COMPAQ 3020 5000-1fe1-5004-5448

So, now, I have "/dev/sda" pointing to LUN 5000-1fe1-5004-569c; and "/dev/sdb" pointing to LUN 3020 5000-1fe1-5004-5448.

From the HP guide ( HP StorageWorks - LUN migration and persistence utilities application notes, AA-RVGXA-TE, and I attached that PDF within this ticket ) about LUN migration and persistence, I saw this:
"Linux assigns SCSI device names dynamically whenever a SCSI logical unit is detected during device discovery. These device names such as /dev/sda, /dev/sdb are mapped to SCSI logical units and can vary across reboots due to any SAN changes.
LUN persistence is the ability of the host to ensure the devices maintain the same name for the SCSI logical units across reboot without getting affected due to the SAN changes."

I worry about after next reboot of the server, the pseudo device names will point to the wrong LUNs, which will screw up the whole filesystem! It seems I have to do something about "LUN persistence", right?

According to the guide, I need to install the LUN persistence utilities "LMPutils.tar.gz", where can I get this package?

The guide says to use "hpdevlabel" to configure this, like:
hpdevlabel add -d /dev/sdb1 -s /dev/myalias
hpdevlabel add -s /dev/raw/raw1 -d /dev/sda1
But it looks like such utility works on partitions( like /dev/sda1, /dev/sda2 ), doesn't create mapping between /dev/sdX and LUN device!

Please help!
Thanks a lot!

[Steven Clementi]

Have you tried the SANSurfer Manager?

I know in Windows, and with Emulex cards, persistant bindings can be performed within the Lightpulse utility that installs with the driver. With QLogic and SANSurfer Manager, you may be able to perform the same function.

Click here http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?pnameOID=315741&locale=en_US&taskId=135&prodTypeId=12169&prodSeriesId=315739 then click your OS version. A listing of utilites comes up along with SANSurfer.

Since I do not work with Linux as much as i would like to, I can not say for sure that what you need is here... some day.


Steven

[Colin Topliss]

The utility hpdevlabel updates the symlink. The mapping to the LUN is done within the 10-HP-Local.rules file.

Use hp_gen_rules to generate the output to put in the Local.rules file (see page 10 of the PDF you attached).

As for the software, try looking under here (haven't found it yet myself, but the HP site does tend to be a little obscure when it comes to finding software).....

http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?locale=en_US&pnameOID=315741&taskId=135&prodTypeId=12169&prodSeriesId=315739&submit.y=0&submit.x=0〈=en&cc=us&y=0&x=0

Regards

Col.

[SAKET_5]

Hi yy,

can i just ask as to why you are not using the native OS level devlabel utility from Redhat?

We had the same issue and instead of using the HP package (which uses the redhat utility anyway!!) we decided to go with the Redhat devlabel package.

just my 2cents worth...

[Sanford Newman]

I have looked at the HP Utility and find that SuSE SLES9 SP2 does not appear in the list of support options from the README.

HPMigrationPersistenceUtil-UL-1.0-1.ia64.rpm - rpm for 64 bit, SLES8 using 2.4 kernel variants

hpudev-cfg-01-1.i386.rpm - rpm for 32 bit, RHEL4 and SLES9 using 2.6 kernel variants.

I need the Itanium version of this.

Thanks.