Sorry for being late, had a few busy days.

Yes, this is a VIOS and you should be root to do changes on a filesystem.

The problem you are facing is - as rbatte1 has already stated - that one of the (physical?) disks the rootvg consists of seems to be missing.

The LVM in short: VGs can consist of one or several "PV"s (physical volumes - disks) and each PV is cut up into "PP"s (physical partitions) of the same size (usually somewhere between 2MB and 2GB). Every logical volume (LV, basically raw disk space which can be formatted into a FS but also be used as paging space or whatever) consists of one or more such PPs mapped to "LP"s (logical partitions). Mirroring, like what you are using, is done by assigning 2 PPs to every LP.

The first thing you need to do is to get rid of the missing disk. If it is possible the best way to do so is to reconnect the removed disk, then remove it from the VG (the command is "reducevg", once it is empty - which is not the case right now). Only then remove it physically again. I suppose this is not possible and the physical disk is long gone. Therefore:

You need to first determine what has been on the 8 used PPs. If you are lucky it was only the copy of the dump-device which are shown as missing in the listing you provided. Try a rmlvcopy command to do so (see the man page for details). If this works and the missing disk is empty continue to remove the missing disk from the VG.

If this doesn't work: report back. It is possible to get the LV- and VG-information back to order, but only by (quite complicated) low-level methods. If it works with the high-level methods then these are preferable, so try these first.

I hope this helps.

bakunin