How does the cutover work, and what happens to DNS and mail?
The final sync applies deletions on the target, then runs the cutover you chose: it repoints the account's DNS records at the target (TTL 300 seconds) and, until DNS has moved, proxies web traffic from the source. Mail that arrives while DNS is still moving is not handled.
Run the cutover
- When the migration shows COMPLETED, choose Finalize….
- Choose Run final sync. It applies deletions on the target, then runs the cutover plan you chose in the wizard.
DNS
- Repointing: the cutover edits DNS records only where the source server is authoritative. Otherwise BackupWall tells you which records to change. Repointed records get a TTL of 300 seconds.
- DNS is merged, never reconciled. A migration adds records and never deletes any. The source's MX record is added next to the target's, so both receive mail until you remove one. Panel-only records (
cpanel,webdisk,autodiscover) are dropped when crossing panels. DirectAdmin takes DNS changes from a queue, so records can appear about a minute late. - Lower your TTLs well before the cutover.
The web proxy
Until DNS has moved, the source can proxy web traffic (HTTP and HTTPS) to the target. It works on some web servers only:
| Source panel | Proxy support |
|---|---|
| cPanel | Needs the root command line and Apache with rewrite, proxy and proxy_http. |
| DirectAdmin | Apache only. nginx, nginx_apache, LiteSpeed and OpenLiteSpeed are refused (DNS is still repointed). |
| Plesk | nginx tested live. Apache was unit-tested only. |
| No panel | No proxy. |
- WebSocket traffic is not proxied. The target sees the source server's IP, not the visitor's. The proxy does not check the target's certificate.
- The proxy is removed by itself only after authoritative DNS answers with the target for the old TTL plus 24 hours, with no request for 6 hours. Otherwise it stays and you get one alert after 7 days.
- If your web server is not supported, switch the proxy off and repoint DNS only.
Mail during the cutover
Mail that arrives during DNS propagation is not handled. The cutover proxy carries web traffic only. IMAP, POP and SMTP are not proxied or relayed. The source account is not frozen and there is no catch-up copy. Mail that reaches the source after the final sync stays there until DNS caches expire.
Do one of these:
- Lower the TTLs well before the cutover.
- Stop mail on the source.
- Run Re-sync after DNS has moved and before you remove the source account.
Still stuck? Open a ticket at portwall.net/billing or write to [email protected], and attach a support bundle. See Report a problem and make a support bundle.