If two redundant paging virtual I/O servers are configured for a shared memory LPAR, the paging device of the LPAR can still be accessed if the primary paging virtual I/O server should fail.

A manual change of the active paging virtual I/O server is also possible with the command “lpar sopgdev” (switch over paging device):

$ lpar sopgdev aix22
$

The command has an immediate effect, the hypervisor uses the previously inactive paging virtual I/O server from now on. It is not easy to see which paging virtual I/O server is currently active. The best option is probably to monitor I/O on the paging device. I/Os on the paging device are only performed on the currently active paging virtual I/O server. The paging virtual I/O server on which I/O on the paging device is seen, is the currently active paging virtual I/O server. The property of being a primary or secondary paging virtual I/O server is irrelevant and does not change with a switchover.