<p>Is it possible to use AIX's mksysb and savevg to create a bootable tape with the rootvg and then append all the other VGs?</p>

First, use savevg to backup any extra volume groups to a file system on the rootvg:
```
```
savevg -f /tmp/vgname
```
```
Compress it if it will be too large, or use the -i option to exclude files.  The easiest way is to exclude all files on the volume group and restore those off of the regular backup device.  Once that is done, create your normal mksysb.
For DR purposes, restore the system using the mksysb, then use restvg to restore the volume groups out of your backup files.  Restore any extra files that may have been excluded, and you're running again.