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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
Y1Udba1GsO12085
71 Posts
1
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
PowerPath-for-Linux-5.7-and-Minor-Releases-Installation-and-Administration-Guide.pdf
sanpad
9 Posts
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December 9th, 2013 14:00
Thank You Javier!!
AlexHCL
2 Posts
0
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
Anonymous
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March 6th, 2014 03:00
Hi Alex,
Kindly refer to the Chapter 7 (Upgrading PowerPath) of the attached document (by Javier) above. Please let us know if that helps. Please feel free to reach us for additional clarification.
Thanks a lot for using PowerPath !
Thanks,
Amit Saha
Senior Product Manager, PowerPath
AlexHCL
2 Posts
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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
Anonymous
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March 10th, 2014 03:00
Hi Alex,
Ok. Could you let us know the OS and its version please?
Thanks,
Amit
Anonymous
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July 14th, 2016 11:00
Hi Guys ,
I tried the above steps for a Boot From SAN server to migrate it to powerpath but could not succeed as we were unable to stop the multipath for boot device .Can anyone let me know is there any additional steps required for migrating from multipath to powerpath for SAN boot devices.
pawelw1
306 Posts
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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