how to upgrade the failover pair?

perl-list perl-list at
Thu May 31 08:35:27 UTC 2018

This is a layman's opinion as i've not done the described procedure below, but I would think you would want to retain the dhcpd.leases file from the secondary and primary and put those back after re-install. 

In other words, do not attempt to copy leases file from primary to secondary as you listed in steps below, but rather retain the dhcpd.leases file from the original install. Copy that file back into place before you start the DHCP server on the secondary. 

I think there are some differences between the primary and secondary leases files such that you would not want one copied to the other. 

> From: "Aleksey Perov" <a.perov at>
> To: "Users of ISC DHCP" <dhcp-users at>
> Sent: Thursday, May 31, 2018 3:14:47 AM
> Subject: how to upgrade the failover pair?

> Hi.

> I have two servers running Debian 6.0.5 with ISC DHCP 4.1.1 in a
> failover pair. Now I need to upgrade them to the latest Debian 9 which
> is shipped with ISC DHCP 4.3.5. Since Debian 6 is too old, the only way
> of upgrading is a clean reinstall (which in most cases is better than
> sequential upgrade 6 to 7 to 8 to 9).

> I have read
> and some other articles, but those documents say nothing about the
> upgrade scenario.

> So the question is: What is the recommended process of _upgrading_ the
> failover pair?

> The draft plan is as follows:

> - stop the secondary;
> - turn the primary into partner-down;
> - reinstall the secondary;
> - wait until the primary reclaims all addresses in all pools;
> - stop the primary;
> - copy leases file from primary to secondary;
> - start the secondary in partner-down mode;
> - reinstall the primary;
> - turn the secondary into normal mode;
> - start the primary.

> Is anything wrong here?

> Any advices and recommendations are welcome. Thanks.

> --
> Aleksey
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the dhcp-users mailing list