HP 9000 Series Service Manual page 115

Troubleshooting
If the system is configured with the primary swap device as the dump device (default
configuration), a problem can occur if savecore is run after the system has been brought
up multi-user. Once the system starts back up, it is free to start swapping over the swap
device. This could corrupt a crash image written out to the swap device.
If the dump device is configured to use another logical volume or file system rather than
the primary swap device, the system's physical memory image remains intact; you can
savecore after the system has been brought up to multi-user mode.
At this point, you can mount a magnetic tape and use the -t option to savecore to save
the system's physical memory image to magnetic tape.
Chapter 3 3- 35