---
title: "Promoting a Secondary Server to Primary"
slug: "promoting-a-secondary-server-to-primary"
description: "If a primary server is offline for too long, it may be desirable to change a secondary server to a primary. Here's how."
updated: 2021-05-04T21:04:48Z
published: 2021-05-04T21:04:48Z
canonical: "kb.isc.org/promoting-a-secondary-server-to-primary"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.isc.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Promoting a Secondary Server to Primary

#### How do I promote a secondary server to primary if the current primary is offline too long?

1. Make sure the expiry timer is sufficiently high, somewhere between multiple days and a month.
2. For the zone definitions in `/etc/named.conf`  (or equivalent):  

(a) Change the `type` statements from `secondary` to `primary` and remove the `masters` statement.  

(b) Add `allow-update` and `allow-transfer` statements as appropriate.  

(c) Possibly add `also-notify` statements as appropriate.
3. Add key definitions if needed.
4. If `masterfile-format text;` wasn't used in `named.conf.local`, convert the zone files to text using `named-compilezone` including the `-j` parameter.
5. If the server's name is different than the former primary, then the `SOA` record for each (to-be) primary zone must be updated.  Since `rndc` freeze/thaw doesn't work on secondary zones, the server probably needs to be shut down.
6. Change the `MNAME` in the `SOA` record to the new server name.

Alternatively, you could try this method:

1. Create an intermediary file that is a list of the zones needed to be able to quickly switch between primary and secondary.
2. Use that file as data for a script (really different m4 macros) to create the proper configurations (at the same time) for both primary and secondary operating modes.  

Each configuration is (effectively) stored in its own file: `/etc/named/zones.master.conf` and `/etc/named/zones.slave.conf`.
3. Dynamically update a sym-link to point to the operating mode of the server.

Primary:

```
/etc/named/zones.conf -> /etc/named/zones.master.conf
```

Secondary:

```
/etc/named/zones.conf -> /etc/named/zones.slave.conf
```

The main `named.conf` file will then simply include the `/etc/named/zones.conf` file.

(This article is based on an August, 2018 post on bind-users@lists.isc.org, by Leroy Tennison, with some edits by ISC. )