I do that with two Debian 10 servers - Postfix, PostfixAdmin, Dovecot, MariaDB, Keepalived. MariaDB in active/active mode, each node accesses the DB via localhost, Dovecot with dsync replication, Keepalived for a virtual ip. The MX record points to each node, DNS A/PTR records for the clients pointing to the virtual ip.

I separated Roundcube from the mail server and have them running on two separate VM's as i didn't want to expose the webserver on the mail servers to the Internet. There is also keepalived on the two webmail VM's for a virtual ip where the users connect to. Both Roundcube instances connect to the DB or SMTP/LDAP server via the virtual ip there.

Working since almost two years without issues.

On 7/9/21 11:15 AM, White, Daniel E. (GSFC-770.0)[NICS] wrote:

• with Roundcube and PostfixAdmin - successfully ?

This is a new setup, running on RHEL 8 with the latest everything.

Has anyone out there set up a high availability pair of Dovecot servers

"Callahan's Law: Shared pain is lessened; shared joy, increased —

thus do we refute entropy" (Spider Robinson)

On 09-07-2021 19:15, White, Daniel E. (GSFC-770.0)[NICS] wrote:

This is a new setup, running on RHEL 8 with the latest everything.

Has anyone out there set up a high availability pair of Dovecot servers - with Roundcube and PostfixAdmin - successfully ?

Yes. NFS or GlusterFS for shared storage, Keepalived, Percona XtraDB+ProxySQL as database backend, Postfix, Dovecot, nginx as reverse proxy for Apache w. PHP-FPM. Suggest you start from the bottom up and *please* add monitoring for all services, look at Nagios/NRPE w. Percona monitoring plugins, more often than not a life saver. If things can go pear-shaped they will :) Cheers,

-- Adi Pircalabu