Migrating to PowerDNS

Before migrating to PowerDNS a few things should be considered.

PowerDNS does not operate as a secondary or primary server with all backends. The Generic SQL and BIND backends have the ability to act as master or slave. See the table of backends which other backends support these modes.

Using AXFR to a Slave-Capable Backend

The easiest way to migrate all your zones from your old infrastructure to PowerDNS is to add all your domains as a slave domain with your current master as the master, wait for the zones to be transferred and change the zones to master. Make sure secondary is set to “yes” in your pdns.conf.

To A Generic SQL Backend

Note

This assumes the schema provided with PowerDNS is in place.

In order to migrate to a Generic SQL backend, add all your domains to the ‘domains’ table with the IP of your current master. On your current master, make sure that this master allows AXFRs to this new slave.

INSERT INTO domains (name,type,master) VALUES ('example.net', 'SLAVE', '198.51.100.101');

Then start PowerDNS and wait for all the zones to be transferred. If this server is the new master, change the type of domain in the database:

UPDATE domains set type='MASTER' where type='SLAVE';

And set primary to “yes” in your pdns.conf and restart PowerDNS.

Or, if you want to use native:

UPDATE domains set type='NATIVE' where type='SLAVE';

To the BIND backend

Create a named.conf with all the domains as slave domains, e.g.:

zone "example.net" in {
  type slave;
  file "/var/lib/powerdns/zones/example.net.zone";
  masters {
    198.51.100.101;
  };
};

Make sure the directory is writable for the pdns_server process and that bind-config parameter references this file. Now start PowerDNS and wait until all zones are transferred. Now you can change the zone type to master:

zone "example.net" in {
  type master;
  file "/var/lib/powerdns/zones/example.net.zone";
};

Don’t forget to enable primary in your pdns.conf and restart, or if this setting was already set, use pdns_control rediscover to load these zones as master zones.

From zonefiles to PowerDNS

Using the BIND backend

To use the BIND backend, set launch=bind and bind-config=/path/to/named.conf in your pdns.conf. Note that PowerDNS will not honor any options from named.conf, it will only use the zone statements. See the BIND backend documentation for more information.

To a Generic SQL backend

There are several methods to migrate to a Generic SQL backend.

Using zone2sql

To migrate, the zone2sql tool is provided. This tool parses a BIND named.conf file and zone files and outputs SQL on standard output, which can then be fed to your database. It understands the BIND master file extension $GENERATE and will also honour $ORIGIN and $TTL.

For backends supporting slave operation, there is also an option to keep slave zones as slaves, and not convert them to native operation.

zone2sql can generate SQL for nearly all the Generic SQL backends. See its manpage for more information.

An example call to zone2sql could be:

zone2sql --named-conf=/path/to/named.conf --gmysql | mysql -u pdns -p pdns-db

This will generate the SQL statements for the Generic MySQL and pipe them into the pdns-db database in MySQL.

Using pdnsutil load-zone

The pdnsutil tool has a load-zone command that ingests a zone file and imports it into the first backend that is capable of hosting it.

To import, configure the backend and run pdnsutil load-zone example.com /tmp/example.com.zone to import the example.com domain from the /tmp/example.com.zone file. The zone is imported atomically (i.e. it is fully imported, or not) and any existing records for that zone are overwritten. This include the SOA record too.

Migrating Data from one Backend to Another Backend

Note

This is an experimental feature.

Syntax: pdnsutil b2b-migrate OLD NEW

This tool lets you migrate data from one backend to another, it moves all data, including zones, metadata and crypto keys (if present). Some example use cases are moving from BIND-style zonefiles to SQL based, or other way around.

Prerequisites

• Target backend must support same features as source from set of domains, zones, metadata, DNSSEC and TSIG. See Backend Capabilities
• There must be no data in the target backend, otherwise the migration will fail. This is checked.

You can perform live upgrade with this tool, provided you follow the procedure.

Moving from source to target

• Take backups of everything.
• Configure both backends to pdns.conf, if you have source configured, you can just add target backend. DO NOT RESTART AUTH SERVER BEFORE YOU HAVE FINISHED
• Then run pdnsutil b2b-migrate old new, the old and new being configuration prefixes in pdns.conf. If something goes wrong, make sure you properly clear ALL data from target backend before retrying.
• Remove (or comment out) old backend from pdns.conf, and run pdnsutil rectify-all-zones and pdnsutil check-all-zones to make sure everything is OK.
• If everything is OK, then go ahead to restart your PowerDNS service. Check logs to make sure everything went ok.