AIX

my AIX server used to have scsi disk hdisk4. Now i removed that disk. But still it is still listed in lspv. So how can i remove the stale entry of it ?

before removing the disk, i did a varyofvg on the only VG i had on it, and then did a exportvg..and then unmapped the disk from the HP array side

Did you remove the disk physically from the server without administrative action an the AIX side? Whenever you are going to remove a disk permanently from an AIX server you need to remove certain pieces of information from the system. You start with the LVM level: stop access to the filesystems, unmount the filesystems, varyoff the VG. Export the VG if you are sure that it will never return (on this particular disk). (Check exportvg and reducevg commands to find out which one applies to you) Then go on by removing the information at the device level: remove the disk's entries from the ODM with rmdev -dl. Only then remove the disk itself. Stick to this sequence as the LVM level commands depend on the ODM entries.
As to the lspv: lspv shows the disks that where available during boot time. Hence it would be better to use lsdev -Ccdisk (or from AIX 5.2 on lsdev -cdisk) to find out which disks are available in the system and whether they are active or defined.

ok that gave some idea..how can i make sure this point "stop access to the filesystems". From user end, i am sure that i am not accessing it, how to check it from the OS side ??

If you can umount it, you ain't using it. If you can't umount, one or more processes are accessing the FS. In this case use fuser and/or lsof (available from the IBM AIX Linux Toolbox page) to find out which process is the culprit.

#set -vx
echo "What do you wish to delete?"
read ITEM
#>/tmp/odmdel.ksh
CLASS="CuAt CuDep CuDv CuDvDr CuVPD"
for i in $CLASS
do
odmget $i | grep $ITEM >/dev/null
if [ $? -eq 0 ];then
ATTR=`odmget $i | grep $ITEM | sort -n | uniq`
echo odmdelete -o $i -q `echo \"$ATTR\"| awk '{print $0}'` >> /tmp/odmdel.ksh
fi
done
chmod 700 /tmp/odmdel.ksh

Nice post. Thanks a lot.