16.2.2. Lease Database
On the DHCP server, the file
/var/lib/dhcpd/dhcpd.leasesstores 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.leasesfile is renamed
dhcpd.leases~and the temporary lease database is written to
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.leasesfile 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.leasesand then start the daemon.