For the VG you are trying to varyon - are they all local disks? If so, whomever has physical access to the box should check for failed disks.
If the disks are SAN, have your SAN person check to see if there are any failed disks on that end and/or make sure the disk hasnt been re-allocated elsewhere (seen this happen a few times).
Add a little color to your PUTTY terminal: faq52-6627