Migrating hosting infrastructure — 100+ DNS zones and mail for dozens of companies
We retired an ageing server, moved authoritative DNS and mail to a new system with full filtering, and brought up new backup infrastructure. Every zone verified, every step with a way back.
- DNS zones analysed and verified
- 111
- server decommissioned
- 1
- new backup capacity
- 5 TB
Context
This one we did for ourselves — but it is exactly what we do for clients. The server providing DNS and mail for dozens of companies ran on a system nearing end of support, and one of the virtualisation hosts needed to be retired.
How it went
Domain audit. Before moving anything, a script checked all 111 zones: which domains actually point at our name servers, which have moved elsewhere, which have expired. The migration covered only what was needed, and stale zones were archived.
DNS. A new primary server replicating to secondaries. TTLs were lowered in advance so the switch propagated quickly — and a rollback would have been just as quick.
Mail. A move to a modern stack: Postfix, Dovecot, spam and virus filtering, webmail, automatically renewed certificates. Mailboxes migrated with permissions and structure preserved, verified after every step.
Backups. A new backup server for virtual machines and containers, with automatic schedules and a notification for the result of every job.
The result
The old server is retired, every service runs on a supported system, and there is full documentation and a zone archive. We apply the same plan — audit, lower TTLs, move, verify — to client migrations.