lvm stuff

note to self

Encountered "Found duplicate PV" warning again, i keep forgetting the solution for some reason. Good KB article is here. Idea is to filter out everything that has multiple device files leaving only one, and making sure the one that is left is the best one to be used. For example, in a multipath environment filter out everything except the multipath'd device node created by the device-mapper or whichever multipath tool that is used. ( Eg. /dev/emcpowera etc. ) Once the changes are in place pvscan and vgscan can be issued and check the warning appears no longer. Example filter rule from the current SLES san-boot setup this was tested is below. It filters out everything except /dev/dm-* devices which are the multipath devices created by device mapper.

filter = [ "a|/dev/dm-.*|", "r|.*|" ]

Once this is tested, mkinitrd should be done to put the changes in to the initrd image to be activated at the boot.