Maybe a little off-topic - but I hope not too much.
Looking for some insight on setting up Dovecot under a virtual server.
In particular, I use VirtualBox - and at the moment, Ubuntu Linux.
Initial questions on configuration:
Caching. It seems to me - and I'm probably wrong - that running a Linux
in a VM on a Linux host, there would be a duplication of caching. That
is, the host server has a file cache - and the VM, which is otherwise a
standard Linux installation, is also going to try to cache its files.
This strikes me as a duplication of effort and waste of RAM. Is this
something I should devote any time to thinking about and trying to
minimize? If so, how?
Mail storage. My current mail store is a RAID-10, using the mdbox format. I wish to continue storing the mail on "raw" disks - not place the mail inside a virtual disk. Accordingly, the VM needs to reach the mail outside the VM environment - which according to conventional wisdom means NFS. My initial testing shows NFS results in a dramatically reduced performance for Dovecot. Given that this NFS access is going to be exclusively for Dovecot, and I'm only running a single server, are there any NFS or Dovecot tweaks I should implement? Is there an alternative connectivity for the VirtualBox environment I should explore?
-- Daniel