On Mon, 15 Oct 2012, Daniel Pittman <daniel@rimspace.net> wrote:
My fallback would be NFS shared ZFS in the domU - much cheaper because you only have one ARC, set of checksums, etc, to manage, but with the added bonus of NFS between the domU and dom0. Fun times.
http://wiki.dovecot.org/MainConfig The above page says "Dovecot can also use dnotify, inotify and kqueue to find out immediately when changes occur" in regard to the IMAP "IDLE" command (waiting for notification of new mail). So it seems that using NFS is going to incur extra overhead for polling (which probably isn't that great) as well as delaying the notification of new mail. This probably doesn't matter much as it seems unlikely that there is a reasonable demand by a user for how soon they should be notified which would also involve frequent enough polling to cause significant load. But it is another reason for not using NFS. It's really a pity that the Xen DomU kernel doesn't have it's own filesystem driver which proxies access to the Dom0. Then things like Inotify would just work. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/