tech.gate.io blog

lspv and other high level lvm commands are reading the pvid from the ODM database, not from the disk itself
this is a great performance improvement, but may lead to an inconsistence of pvids

when the storage admin for example, deletes a hdisk and maps a new one, before you delete it on the system, after running "cfgmgr/cfgdev" the new hdisk appears as the old one with it's old pvid

mapping such an unlucky disk to a lpar, results in different pv ids on lpar and vio server, which may be an absolute disaster

to check the real pvid, read the disk-header directly with the command

od -A n -j 128 -N 8 -x /dev/hdisk120

 
compare this value with the one from lspv
if it's different, use

chdev -l hdiskx -a pv=yes

 
this command will even work, if the disk is already mapped, since the disk already has a pvid, so chdev just reads the pvid from the disk-header, and writes it to the ODM