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  • 1.  reserve lock issue in dual vio servers

    Posted Tue July 13, 2010 08:59 PM

    Originally posted by: enmanasu


    Hi,

    I had "FCP errors" on a dual vio servers running on P6-595 frame. As advised by IBM & EMC,san switch port was reset(we did one by one hba&vio) and FCP errors has been stopped. BUT,BUT we noticed that reserve_lock was changed to yes for the disks on both the vios..

    Now aix lpars in the frame are running and i would need to know any possible options to change reserve_lock to no without taking them down..?
    Do I need to remove the mappings on vio to make reserve_lock change..?

    Take lpars down and one vio down,can i change it on other vio and then startup the other vio and then lpars..in this way no need to remove the mappings on vios..

    Pls suggest best option for this..

    shan
    #AIX-Forum


  • 2.  Re: reserve lock issue in dual vio servers

    Posted Wed July 14, 2010 09:25 AM

    Originally posted by: broberts


    I love it when EMC steals and resets the locks back on the disks! Given that you're noting the reserve_lock attribute instead of the reserve_policy attribute, I'm assuming that you are running PowerPath on your VIO servers.

    The short answer is that you will need an outage. Trying to do it on one VIO server will allow the other VIO server to steal the disks, thereby making them "device busy" when you try to flip the lock.

    The long answer is that you will need to take your LPARs down, unmap the devices from their vadapters, and then run the chdev commands to reset the reserve_lock to "no". Also, make sure that you run the chdev command again with the -perm flag (or -P in oem mode) to double-verify that the ODM has it set to permanently leave it off.

    If you are in a PowerPath environment that is not emulating a MPIO-mode, I would also suggest turning the reserve locks off not only on the hdiskpower devices, but also the underlying hdisk devices to make sure that all of the paths have it turned off. We have seen occurrences where one path may have the lock and cascade it up.

    Good luck! I know it's a painful mess.
    #AIX-Forum


  • 3.  Re: reserve lock issue in dual vio servers

    Posted Wed July 14, 2010 04:33 PM

    Originally posted by: enmanasu


    hi,

    thanks for ur reply..

    to avoid remapping the disks on vio which is again a big task..can i try this

    take all lpars down
    take vio1 down.
    change reserve_lock for all disks on vio2..and then bring up vio1 and then change the reserve_lock
    start lpars..

    will the above steps help..? or is it going to effect while bringing the 2nd vio..?

    pls clarify
    #AIX-Forum


  • 4.  Re: reserve lock issue in dual vio servers

    Posted Wed July 14, 2010 08:17 PM

    Originally posted by: shargus


    You will need to unmap the disk to change the attribute. Otherwise, you will get a "device busy" error.

    You MIGHT be able to pull some tricks with PowerPath (remove one disk from hdiskpower device, change attribute, put it back in, repeat for rest of disks), but I wouldn't count on it. It depends a lot on the version of PowerPath, the patch level of your VIOS, etc.

    The best way to do it is to shut down the lpar, fix the disks, then bring it back up.
    #AIX-Forum


  • 5.  Re: reserve lock issue in dual vio servers

    Posted Sun July 18, 2010 07:10 PM

    Originally posted by: enmanasu


    hi,

    thanks for ur reply..

    lpars are down..vio1 is down...still do i get device busy error on vio2 if i change the reserve_lock? I dont know who will be using thoese disks except vio2..

    just looking for ways to avoid disk remapping..

    regards
    shan
    #AIX-Forum


  • 6.  Re: reserve lock issue in dual vio servers

    Posted Tue July 20, 2010 09:33 AM

    Originally posted by: Renaud


    Like Sargus said, you have to unmap the disk to change the policy path. With a little shell script I guess it's not easy to map again the disk.
    #AIX-Forum


  • 7.  Re: reserve lock issue in dual vio servers

    Posted Fri July 23, 2010 07:38 AM

    Originally posted by: bcathelyns


    Hello, i do not think that unmapping is necessary,
    What i would do is :

    1 : taking partition down
    2 : get list of all vtd and execute the following command like this : rmdev -dev <VTD> -ucfg
    This will unconfigure the vtd without removing it and you should be able to change the reserve_lock to no.
    3 : chdev -l hdiskpowerxxx -a reserve_lock=no
    4 : cfgmgr which will re-enable all VTD
    5 : check on second vio that all hdiskpower have reserve_lock set to no
    6 : cfgmgr on both vio to re-enable VTD
    6 : Check with lsmap that all VTD are available on both vio
    7 : restart partitions.
    #AIX-Forum


  • 8.  Re: reserve lock issue in dual vio servers

    Posted Wed August 11, 2010 11:40 AM

    Originally posted by: mikeysky


    I've always unmapped to fix issues with reserve lock. I can see where it would work without unmapping if the LPAR was down. To avoid the downtime, a new disk with reserve lock set correctly can be used to swap out the one with issues.

    1. Get new or used disk(s) on both VIO servers.
    2. Set reserve lock = "no" on both VIO servers for the new disk(s).
    3. Map to client LPAR with reserve lock issues.
    4. Extend the volume group with the bad disk to the new good disk.
    5. Use migratepv to free up the bad disk.
    6. Run reducevg and rmdev to remove the old disk
    7. Unmap the old disk.
    8. If the disk being replaced is a rootvg disk, relink /dev/ipldevice and run bosboot.

    This is labor intensive, but fixes the problem without downtime.
    #AIX-Forum


  • 9.  Re: reserve lock issue in dual vio servers

    Posted Wed August 11, 2010 07:12 PM

    Originally posted by: EricGapinski


    Just to throw one more item at this. You likely want to look for the emc_reserve script from the EMC powerlink site. This script will let you set the ODM defaults for the EMC disks to reserve_lock=no, rather then the default default of reserve_lock=yes. EMC lists this as a "requirement" for dual VIO setups with PowerPath, and should prevent the issue that you saw, as well as having the benefit of not needing to make the reserve_lock modification to an hdiskpowerXXX ever time you bring in a new LUN.
    #AIX-Forum


  • 10.  Re: reserve lock issue in dual vio servers

    Posted Tue March 01, 2011 04:31 PM

    Originally posted by: Randall.Swank


    shargus wrote:
    You will need to unmap the disk to change the attribute. Otherwise, you will get a "device busy" error.

    You MIGHT be able to pull some tricks with PowerPath (remove one disk from hdiskpower device, change attribute, put it back in, repeat for rest of disks), but I wouldn't count on it. It depends a lot on the version of PowerPath, the patch level of your VIOS, etc.

    The best way to do it is to shut down the lpar, fix the disks, then bring it back up.

    I understand this part, Many thanks to your description! It is exactly what I need, It's very valuable.
    #AIX-Forum