AIX

Can't you just remove the entry for the filesystem in /etc/filesystems and then dd zeroes over the first part of the rlv (raw logical volume character device)? (Just a hunch, my AIX is not so fluent).

For reasons that I can't demonstrate right now, because I don't have access to an AIX system, I'm guessing that's really not a great idea!

Could work - I did not try it ever, but to be on the sure side, I recommend what I already posted. It should be no big deal to delete the fs + LV and just recreate the LV. That is not much of a work to do and keeps everything in consistency, ODM, /etc/filesystem ... ie. keeps off further problems.

This works exactly as Zaxxon said in his first post but now I feel we need some more details. After all we are talking LVM here. The AIX administrator would rmfs the filesystem after he stored the LV mapping into a file. This is done easily with lslv -m <yourlv> or lspv -M <lvhdisk> | grep <yourlv> command. While the rmfs command removes the filesystem entries and the LV information from the VG the data will be intact on the media surface and the VG structure for disk usage remains unchanged. Thus the AIX admin then recreates the LV with the mapping information (mklv ... -m <mapfile>) and ends up with the original LV but without the filesystem. A map file's syntax consists of two fields. First field is what hdisk is being used and second field is the number of the Physical Partition PP that is used on that particular hdisk:

Code:

hdisk1:230
hdisk1:234
hdisk4:192

This works like a charm (as most things with AIX LVM) and as long as the order of the PP is not changed the data in the LV will be accessible/usable. I.e. the order of the PP in the map file must be according to the Logical Partition LP. In the example given LP No.1 is on hdisk1 PP 230, LP No. 2 is on hdisk1 PP 234 and LP No. 3 is on hdisk4 PP 192. HTH