Diskdump report error messages when restart the diskdump service

After changing the diskdump configuration and restarting the service, the following errors appear in /var/log/messages.

diskdump: diskdumpctl: failed to add /dev/hdb!
diskdump: activating failed
kernel: disk_dump: shut down

This happens because the Linux version in use does not support a full hard disk as a dump partition. To fix it, create a partition on the hard disk and use that partition for dumping memory information.