Uninstalling powerpath when your rootvg resides on a SAN LUN, is not so easy, because you can’t install concurrently the MPIO disk driver fileset, with the one you’re using with powerpath ! And you won’t be able to uninstall the latter (in order to install MPIO support for your disks), unless you wanna play with the ODM.
But first things first :
Unconfigure powerpath
# powermt unmanage dev=all
PS : on some older versions (like 5.3 SP1), the argument « all » is not valid, you will need to specify each volume
specifically.
If you encounter this message (because you have open VG’s on the disks), don’t worry, the unmanage option will be active for the next reboot:
# powermt unmanage dev=hdiskpower11 Cannot remove device that is in use: hdiskpower11 Device(s) will be unmanaged on Reboot.
If not done yet, unmanage your rootvg hdisk and reboot to get rid of all powerpath managed stuff:
# pprootdev off # shutdown -Fr
Uninstall powerpath
Now we can uninstall powerpath:
# installp -u EMCpower [..] Installation Summary -------------------- Name Level Part Event Result ------------------------------------------------------------------------------- EMCpower.encryption 5.5.0.5 USR DEINSTALL SUCCESS EMCpower.migration_enabler 5.5.0.5 USR DEINSTALL SUCCESS EMCpower.mpx 5.5.0.5 USR DEINSTALL SUCCESS EMCpower.base 5.5.0.5 USR DEINSTALL SUCCESS #
Install MPIO… Failure
As I said, you can’t have EMC.Symmetrix.fcp.rte and EMC.Symmetrix.fcp.MPIO.rte together on the same system, as you can see below when I try to install it:
FAILURES -------- Filesets listed in this section failed pre-deinstall verification and will not be removed. Dependency Failures (Deinstall Operation) --------------------- SELECTED FILESETS: The following is a list of filesets that you asked to remove. They cannot be removed until all of their dependent filesets are also removed. See subsequent lists for details of dependents. EMC.Symmetrix.aix.rte 6.0.0.0 # EMC Symmetrix AIX Support So... INSTALLED DEPENDENTS: The following filesets are dependents of one or more of the selected filesets listed above. These must be removed before or with the filesets that you selected. To remove these dependents with the selected filesets, specify the option to automatically remove dependent software (-g flag). EMC.Symmetrix.fcp.rte 6.0.0.0 # EMC Symmetrix FCP Support So... << End of Failure Section >>
–> When you uninstall powerpath, the device driver is still in use for your disks. But you can’t install the latter when the former is still present . How to manage that ?
Clean up a bit
I like to have a clean and simple configuration before starting this kind of operation : I delete all hdisks (before this step you need to umount FS and varyoff vgs , of course) :
# lsdev -cdisk |awk '{print "rmdev -dl "$1}' |ksh Method error (/etc/methods/ucfgdevice): 0514-062 Cannot perform the requested function because the specified device is busy. hdisk1 deleted hdisk2 deleted # lspv hdisk0 00f688f5a829fc18 rootvg active
The problem is that the rootvg is in use, and you cannot delete it , hence you cannot uninstall the symmetrix.fcp.rte package.
So we have to find another way, which is modifying the rootvg’s hdisk’s ODM entry:
ODM modification
# lsdev -c disk hdisk0 Available 10-T1-01 EMC Symmetrix FCP VRAID # odmget -q "name=hdisk0" CuDv CuDv: name = "hdisk0" status = 1 chgstatus = 2 ddins = "scsidisk" location = "10-T1-01" parent = "fscsi0" connwhere = "11" PdDvLn = "disk/fcp/SYMM_VRAID"
First we need to backup the definition in a text file, then backup the CuDv base :
# odmget -q "name=hdisk0" CuDv > /tmp/hdisk0.odm # cp /etc/objrepos/CuDv /etc/objrepos/CuDv.bak
Let’s edit the text file in order to change the disk’s definition to the standard no-driver « MPIO Other FC SCSI Disk Drive » definition (if you don’t have perl installed, just edit manually the file, changing the line PdDvLn = [your disk driver] by PdDvLn = « disk/fcp/mpioosdisk ») :
# perl -pi -le 's/disk\/fcp\/SYMM_VRAID/disk\/fcp\/mpioosdisk/g' /tmp/hdisk0.odm
Now we erase the disk’s definition in its ODM entry which is still in my case « EMC Symmetrix FCP VRAID » :
# odmdelete -q "name=hdisk0 and PdDvLn=disk/fcp/SYMM_VRAID" -o CuDv 0518-307 odmdelete: 1 objects deleted.
We load the modified ODM entry into the ODM :
# odmadd /tmp/hdisk0.odm
Verification :
# lsdev -cdisk hdisk0 Available 10-T1-01 MPIO Other FC SCSI Disk Drive
Ok so the disk is no longer recognized as a symmetrix disk, we should be able to uninstall the driver !
Uninstall FCP driver
In my case I had an extra problem concerning this step :
# installp -u EMC.Symmetrix.fcp.rte +-----------------------------------------------------------------------------+ Pre-deinstall Verification... +-----------------------------------------------------------------------------+ [...] 1 Total to be deinstalled installp: bosboot verification starting... installp: An error occurred during bosboot verification processing.
Actually my /dev/ipldevice was missing, I had to recreate it :
# ls -ltr /dev/ipl* crw-rw---- 2 root system 10, 1 May 15 14:29 /dev/ipl_blv # ln -f /dev/rhdisk0 /dev/ipldevice
then I re-ran the uninstallation :
# installp -u EMC.Symmetrix.fcp.rte +-----------------------------------------------------------------------------+ Pre-deinstall Verification... +-----------------------------------------------------------------------------+ Verifying selections...done Verifying requisites...done Results... [..] installp: bosboot process completed. +-----------------------------------------------------------------------------+ Summaries: +-----------------------------------------------------------------------------+ Installation Summary -------------------- Name Level Part Event Result ------------------------------------------------------------------------------- EMC.Symmetrix.fcp.rte 6.0.0.0 ROOT DEINSTALL SUCCESS EMC.Symmetrix.fcp.rte 6.0.0.0 USR DEINSTALL SUCCESS
MPIO installation (again)
OK so now we should be able to install the MPIO supported driver :
Installation Summary -------------------- Name Level Part Event Result ------------------------------------------------------------------------------- EMC.Symmetrix.fcp.MPIO.rte 6.0.0.0 USR APPLY SUCCESS EMC.Symmetrix.fcp.MPIO.rte 6.0.0.0 ROOT APPLY SUCCESS
Be sure to run bosboot command and verify your bootlist, before rebooting just in case…
Now we can reboot the server and check with lspath and lspv that our disks are now managed by MPIO!
Links
Special Thanks to http://unixadmin.free.fr/?p=179
http://www-01.ibm.com/support/docview.wss?uid=swg21307030
http://unixadmin.free.fr/?p=185
EMC² Powerpath official Documentation