Migrating from Multipath to Powerpath on RedHat
Introduction
Powerpath is the multipathing solution for EMC arrays. The multipath package is so buggy on RedHat that you shouldn’t install it in production environments. This migration has been released on RedHat 4.6.EL.
Reminder: Multipathing brings redundancy functionalities with 2 links on a disk array without having I/O errors.
Uninstalling multipath
Multipath package name (if installed) can be found this way:
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Next, you just need to use the package name and add it to the rpm command:
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Now reboot!
Installation
Now we’ll install the package. Take it from the CD or anywhere else and install it:
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Now you’ll need to launch the license key command:
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Now update the initial ramdisk:
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Then reboot again!
Powerpath verification
You may need to start Powerpath service:
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And also may reboot the server again. Now enter powermt command to verify if your LUN can be shown:
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You can also check that you have emc devices:
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Configuring LVM
Now all is ok, but you need to recover your previous partitions from LVM. So edit the LVM config file and add these arguments:
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Now you can reboot or rebuild the LVM cache:
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Now you should see all your disks :-). Look also at the /dev/mapper
and you’ll see them too.
Last updated 03 Jun 2008, 12:10 CEST.