[Dovecot] Highly Performance and Availability

[Ed W]

I think Stan pretty much covered how to do this stuff *properly*, 
however, for those following along in the bedroom, there are a couple of 
interesting projects what might get you some of the ESX features (surely 
at the expense of far more support and likely reliability, but needs 
always vary...)

Note, I have no experience with any of these projects, they simply 
caught my eye for further research...

- Latest KVM+QEMU includes some of the desirable ESX features including 
hot migration
- Apparently Redhat have a nice management utility for this
- Or try ProxMox: http://pve.proxmox.com/wiki/Main_Page

(cheap) High availability storage seems to come down to:
- iSCSI
- Add redundancy to the storage using DRDB (I believe a successful 
strategy with Dovecot is pairs of servers, replicated to each other - 
run each at 50% capacity and if one dies the other picks up the slack)
- Interesting developing ideas are: PVFS, GlusterFS (they have an 
interesting "appliance" which might get reliability to production 
levels?), CEPH (reviews suggest it's very easily days)

None of these solutions gets you an "enterprise" or proper high end 
solution as described by Stan, but may give some others some things to 
investigate

Cheers

Ed W