On the DHCP server, the file /var/lib/dhcpd/dhcpd.leases stores
the DHCP client lease database. Do not change this file. DHCP lease information
for each recently assigned IP address is automatically stored in the lease
database. The information includes the length of the lease, to whom the IP
address has been assigned, the start and end dates for the lease, and the MAC
address of the network interface card that was used to retrieve the lease.
All times in the lease database are in Coordinated Universal Time
(UTC), not local time.
The lease database is recreated from time to time so that it is
not too large. First, all known leases are saved in a temporary lease database.
The dhcpd.leases file is renamed dhcpd.leases~ and the temporary
lease database is written to dhcpd.leases.
The DHCP daemon could be killed or the system could crash after
the lease database has been renamed to the backup file but before the new file
has been written. If this happens, the dhcpd.leases file does not
exist, but it is required to start the service. Do not create a new lease file.
If you do, all old leases are lost which causes many problems. The correct
solution is to rename the dhcpd.leases~ backup file to dhcpd.leases and
then start the daemon.
