S3/remote storage for dovecot community edition

Help with Setup/Upgrade
1
  1. Does anyone have experience to store the mailboxes of dovecot on a remote server?
  2. I don’t think Maildir + NFS is feasible, feels slow, and I’m not sure if optimization will help
  3. Some of my mailboxes are at 20GB, so I don’t think mdbox is the way either
  4. I tested imap proxy (fastest), imapc (slow, maybe fixable with dovecot 2.4)
  5. I saw some options to use S3 storage, anyone can share experience?
  6. Or something I might have missed?
2

Have you looked at iSCSI (eg. open-iscsi)?

You’d have a “server” box that provides one/more virtual disk devices. The virtual disks could be backed by an actual disk, or just a file, so it’s quite flexible. The “client” (your MIAB box) mounts the remote disk similar to mounting a local device, so you could mount at (say) /home/user-data, or wherever suits you.

Setup for client and server is “traditional” Unix, config files etc. Plenty of info on the web. Setup has several levels of necessary config, but if you config and test each level in turn, it’s not hard to get right.

I’ve found performance to be good, better than NFS, assuming you have normally modern network - I didn’t notice much difference between local spinning disks and same over iSCSI. I wouldn’t use it over “internet” links though … it would work, but speed, latency, and reliability might cause problems.

If you have control of the network, put the storage stuff on its own isolated subnet, for control and security. Better still, you’d use dedicated network adaptors and cabling to completely isolate storage traffic from other network activity, but that’s for serious players.

For any remote storage, the obvious failure mode (storage server is not accessible) can have “interesting” side effects. Just something to consider :wink:

PS. If you’re in a data centre and paying for bandwidth, anything like this will substantially increase your traffic.

3

Thanks, no I have not, any good references?

4

After some research on iscsi, I think its meant for subnet and not remote like over the internet.

What does it take to come up with a S3 plugin for dovecot?