Definitive guide to running ObjectiveFS on top of a Clustered File System?

[A. Schulze]

Am 02.06.21 um 17:09 schrieb Roel van Duijnhoven:
> I am working on migrating a Dovecot system with + 50.000 users / 5TB on mail data to a new set-up that is better scalable. But I found it difficult to find a good solution. In this email I lay out what I learned, in the hope that others can profit. But also others can help me on this design before I actually start migrating.

Hello Roel,

we're also planing a similar migration but choose a slightly other way:
- we split our users in a number of shards (10-20k per shard)
- lmtp and imap traffic hit a number of director servers (TCP loadbalancer or dns-rr)
- director determine the user's shard and direct the connection to the right shard backend
- a backend (pair of two machines) authenticate imap traffic and dsync to it's secondary

advantages:
- no cold standby machines
- scalable by adding pairs of backends
- scalable by adding new single directors
- every machine could be taken offline for maintenance
- every machine could fail without data lost or service degradation
- no proprietary software needed

The are our ideas ...
Andreas