sanpad

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10 years ago

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sanpad

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December 5th, 2013 11:00

Migrating to EMC powerpath from Linux DM

Is migrating the multipath to EMC powerpath from Linux Device Mapper is a disruptive or non-disruptive process??

Is there any document which gives the instructions on doing that?

Thanks

  • 3948

    1

    Posted December 5th, 2013 13:00

    Hi sanpad,

    PowerPath-for-Linux-5.7-and-Minor-Releases-Installation-and-Administration-Guide (attached) describes the process in page 42:

    1. Blacklist all devices in /etc/multipath.conf

        a. Save a copy of /etc/multipath.conf as /etc/multipath.conf.bak for backup if it already exists.

        b. Edit /etc/multipath.conf so that it contains only the following lines:

              blacklist {

                  devnode "*"

              }

    2. Ensure dm-multipath does not start automatically at boot.

        # chkconfig multipathd off

        # chkconfig --list multipathd -- - -Service should be off on all run levels

    3. Recreate initramfs so that dm-multipath is excluded from initramfs.

        # dracut /boot/initramfs-wo-DM-$(uname -r).img $(uname -r)

    4. Add a new boot entry with the initramfs file created in previous step in the /boot/grub/menu.lst file.

    5. Reboot the host with the new initramfs image and ensure dm-multipath does not have any devices configured.

        # multipath -ll --- should not return any dm devices

    As you can see, removing dm-mpio requires rebooting the host. PowerPath installation doesn't require any reboot.

    Regards

    Javier Soriano

    PowerPath Corporate Systems Engineer

    1 Attachment

  • sanpad

    9 Posts

    3948

    0

    Posted December 9th, 2013 14:00

    Thank You Javier!!

  • AlexHCL

    2 Posts

    3948

    0

    Posted March 5th, 2014 23:00

    Hi,

    Could you help for upgrading from 5.5 to latest 5.X version. We are using 5.6 b143. Do we need to upgrade the PowerPath version also? Thanks a lot.

    Regards,

    Alex

  • AlexHCL

    2 Posts

    3948

    0

    Posted March 9th, 2014 20:00

    Hi Amit Saha,

    I have checked but the document doesn't include any compatibility information. We want to make sure no upgrade and configuration is needed after the kernel is updated.

    Thanks!

    Alex

  • pawelw1

    306 Posts

    3948

    0

    Posted July 14th, 2016 23:00

    Hi,

    You might need to try the procedue described in the PowerPath Installation Guide - boot the system with single (boot) LUN masked only, make sure it's visible down one path - then reconfigure LVM/fstab to use the physical device instead of /dev/mapper, then follow rest of the instructions in order to disable DM-MPIO and install PP.

    Hope that helps!

    Pawel