Error "0505-102 alt_disk_install: mkvg has returned an error"

Environment

Problem

Solution

1. The fileset that installs alt_disk_install is bos.alt_disk_install.rte.
2. There are two options in using the alt_disk_install command:
   • Install a mksysb on an alternate disk.
     With this option, a mksysb tape or image is loaded onto an alternate disk and serves as a rootvg.
   • Clone the rootvg to an alternate disk.
     With this option, the current rootvg is copied to another disk.
3. The main purpose of making duplicate rootvgs is for short-term backup/recovery procedures. It can be useful, during a system upgrade, to have a backup from which to quickly recover if necessary. For example, if the rootvg is on hdisk0 and the altinst_rootvg is on hdisk1, in an upgrade failure, the user can run the bootlist command to change the bootdisk to hdisk1 and reboot off of that disk.
4. IBM does not support making a clone of the rootvg with the alt_disk_install command to take that hdisk to another system. A mksysb must still be made to tape or, alternatively, the Network Install Manager (NIM) can be used.
5. Once the alternate rootvg has been made on the other disk with the alt_disk_install command, do NOT export the volume group manually under any circumstances. This will corrupt the rootvg, removing all the stanzas from /etc/filesystems. In the event this does occur, there is a solution. Ensure that the altinst_rootvg (the name given to the cloned rootvg) disk does not display a volume group with the lspv command. Run the following:

   # imfs rootvg
   

   This will re-populate the /etc/filesystems file. If the system is rebooted before this command can be run, the RAM /etc/filesystems file will have to be copied to the hard disk rootvg /etc/filesystems file. A new boot image should be made and the bootlist set back to the proper disk.
6. There can only be one altinst_rootvg imported on the system at a time. An altinst_rootvg cannot be created on two separate disks. If this is attempted, the following error displays:

   0505-102 alt_disk_install: mkvg has returned an error
   0516-360 getvgname: The device name is already used; choose
            a differennt name
   0516-862 mkvg: Unable to create volume group
   

   If this error is received, the alt_disk_install cannot be run until the current alt_disk_install is removed (explained in the following step).
7. Exporting the alt_disk_install altinst_rootvg volume group
   The alt_disk_install creates the volume group altinst_rootvg. This is properly removed with the following command:

   # alt_disk_install -X
   

   This will fix the Object Data Manager (ODM) tricks that were performed and remove the volume group.