Multiple VPS use in a Highly Available setup?

[tycoonbob]

Are there any current abilities to setup MIAB in a HA fashion? For instance, I have run MIAB for about 1.5 years now, and quite like it. Super easy to manage, and just works. However, I’ve recently had some downtime with my VPS provider which I’m not happy about. Stuff happens; I get it…but if I could run 2 small instances with 2 different VPS providers, that downtime would had been a non-issue.

Is there any documentation available for an active/passive setup, or even active/active?

[murgero]

With MIAB this is only possible by setting a secondary MX record. Try this(Although a second MIAB with rsync would do the Job just fine): https://www.howtoforge.com/postfix_backup_mx

Then try the following in your DNS server(If it is your MIAB Primary DNS server, switch to external server for primary DNS otherwise other servers cannot get secondary MX record when MIAB is down):

MX 10 box.example.com.
MX 20 box2.example.com

The numbers you see above are priority, so if the first one (MX 10 box.example.com) fails, most servers will attempt to send the mail to the secondary server (MX 20 box2.example.com)

This setup requires that you ARE NOT using MIAB as your primary DNS, but as a slave. This is so that if MIAB does go down for whatever reason other servers can still access your DNS, and see the secondary MX record.

[tycoonbob]

I appreciate the response. I’m actually not using MIAB for DNS, as I am using my registrar’s (Namecheap) DNS. I realize it would be simple to setup a second box as a standalone box, and just use MX records for routing, but I wasn’t sure if I could just use rsync to keep mailboxes synced between the two hosts, and also how that would play out with things like caldav/carddav (two things I use as much as email, but I don’t care about owncloud for file storage).

But in regards to mail only, I would think using postfix as a relay would be a better back up solution. Otherwise, I would have to make sure I had a full 2-way sync between mx01 and mx02 for mailboxes. More importantly, mail clients (activesync or imap) would still only be pointing directly to mx01, so mail would not be directly accessible without reconfiguring for mx02.

I think with that in mind, it may just be best to have a postfix relay, based on that link you sent.

FYI, this all stems because I have a working MIAB instance, but I can’t ssh into it any longer so I’m trying to decide what I’m going to do. I disabled password auth, the server that had the key access died, and I didn’t save the private key anywhere. I thought I knew the root password (over console), but it doesn’t work. Effectively, I’m locked out of my VPS MIAB instance, and backups are about 2 weeks old now. I tried booting Ubuntu into recovery (trying to get to a root shell so I can try and change the password) but the box gets hung when booting to recovery. Ugh…tough spot.