Topic
3 replies Latest Post - ‏2012-10-22T16:41:52Z by ThomasJO
ThomasJO
ThomasJO
4 Posts
ACCEPTED ANSWER

Pinned topic Setting default parameters for storage attributes

‏2012-10-18T23:36:49Z |
Here's my situation. I have setup my Storage drives to use MPIO, no_reserve and the round_robin algorithm. And it's working very well for us. However, whenever we add drives to the LPARs we have to remember to manually set the new drives to no_reserve and round_robin. Many times this step is forgotten and then there are drives that are not set to "load balance" their I/O. I seem to recall reading somewhere that there is a way (i.e. not manually manipulating the ODM) to set the default settings so new drives would already come in with the no_reserve and round_robin already set. However, I can not find / remember how to do it.

Am I remembering this correctly? If so, how do I do it?

Any help will be appreciated. Thanks.
Updated on 2012-10-22T16:41:52Z at 2012-10-22T16:41:52Z by ThomasJO
  • j.gann
    j.gann
    191 Posts
    ACCEPTED ANSWER

    Re: Setting default parameters for storage attributes

    ‏2012-10-20T15:39:30Z  in response to ThomasJO
    replace the default value in the PdAt ODM Class entry matching the uniquetype of your disk device and the attribute name of the desired attribute (reserve_policy ... whatever)

    odmget, odmchange commands should do

    Joachim Gann
  • The_Doctor
    The_Doctor
    91 Posts
    ACCEPTED ANSWER

    Re: Setting default parameters for storage attributes

    ‏2012-10-20T18:14:39Z  in response to ThomasJO
    I think your original question has already been addressed.... here's an alternative:

    SDDPCM may not be for everyone, BUT IF SDDPCM fits in your environment.... I think you'll like the default settings of "no_reserve" & "load_balance". Works for both VIO Servers and AIX Client LPARs.

    You didn't mention the disk sub-system(s) you were using so you'll need to decide if SDDPCM is a fit for you.
  • ThomasJO
    ThomasJO
    4 Posts
    ACCEPTED ANSWER

    Re: Setting default parameters for storage attributes

    ‏2012-10-22T16:41:52Z  in response to ThomasJO
    Thanks guys.

    It dawned upon me this morning that what I was thinking of was an EMC supplied script (We have EMC VMAX storage). When I looked through the script I saw it is doing an odmget and an odmchange in the background.

    symm_fcp_mpio_change_no_reserve()
    {
    print "************************"
    print "* Status BEFORE update *"
    print "************************\n"
    odmget -q'uniquetype LIKE disk/fcp/MSYMM* and attribute=reserve_policy' PdAt | egrep "uniquetype|deflt"

    odmchange -o PdAt -q"uniquetype LIKE disk/fcp/MSYMM* and attribute=reserve_policy" << EOF

    PdAt:
    deflt = "no_reserve"
    EOF
    print " ODM updates - reserve_policy=no_reserve - installed sucessfully \n"

    print "************************"
    print "* Status AFTER update *"
    print "************************\n"
    odmget -q'uniquetype LIKE disk/fcp/MSYMM* and attribute=reserve_policy' PdAt | egrep "uniquetype|deflt"
    print "\n
    }
    Looks like this is probably the best way to handle the situation.