Alternate links

[Keith Floyd]

Hi

I am connected to EMC disks via direct fibre cable.
I will be configuring data vol etc on them
I will in near future be re-connecting via fibre hub and dual paths
I would like to then force access of half disks down one path half down the other.
What will be the best way to convert the device files

Thanks
Keith

[John Palmer]

LVM uses the order of declaration of disks to a volume group to determine which is the 'primary' and which is the 'alternate' link.

One you have vgextended your alternate links to your volume group(s), you can then vgreduce your old primary link (the new alternate path becomes the primary) then vgextend the old primary and it becomes the alternate.

You can also use the 'pvchange -s' command to temporarily switch a disk to use it's alternate link.