I have ispconfig configured in multi-server mode, where I have one server for the panel, and two servers for dns, in this case NS1 and NS2. My server containing ns1 crashed, how can I install a new ns1, integrate it into the current panel server and make ns2 a mirror of the new ns1 without any downtime and without losing the existing records and dns zones?
Find @Taleman profile and follow his link on setting up a dns server as I found that all dns matters already covered by that. To note, one need to consider between mirroring a dns server or not, because mirroring may not be the best practise for it. Adding a new server to multi server setup has already been discussed many times, so nothing to add to it, just search and learn from it in here.
If this is a hardware server you should consider setting up RAID in the future to tolerate 1 faulty disk without loosing all data. And it would be wise to backup such critical system to be able to restore them in such scenarios.
If no server backup is available I would install a new server using the same ip('s) and edit records in tables dns_soa and dns_rr in dbispconfig changing the old server_id to the new one. Afterwards resync the new server in ISPC and all should be working again.
