On 6/27/2011 6:06 PM, Noel Butler wrote:
I hope this is a lightly used server and does not do any real level of mail traffic else you'll soon regret running in any VM :) Just all the mailing lists I subscribe to :)
means NFS. My initial testing shows NFS results in a dramatically reduced performance for Dovecot. Given that this NFS access is going to
Hrmmm, something amiss somewhere then, I'd put it down to the VM, many people on this list use NFS and have no problems.
Well - the wiki tells me, "Both the mmap_disable and indexing to NFS will result in a notable performance hit."
Though you have not mentioned what version you run, on 1.2.x using:
mmap_disable = yes mail_nfs_storage = yes mail_nfs_index = yes Why do people insist on specifics :) ? At the moment, 2.0.13.
Something still a bit unclear - cue Timo interjection here. The parameters listed for nfs installations (mmap_disable, doctlock_use_excl, mail_nfs_storage, mail_nfs_index) - are they necessary for data integrity, and/or do they compensate for NFS latency and improve performance? My confusion stems from the unusual? condition where the mail store is NFS based - but is otherwise dedicated to the single Dovecot instance, so simultaneous writes & locking *shouldn't* be a concern.
Particularly as I'm using mdbox, local index storage seems inappropriate (as I don't want any critical data stored within a virtual image).
Daniel