Performance proko2 client revisited

[T. Ribbrock]

Hi all,

a while back I mailed about the performance of the proko2 client being
very sluggish. By now, I have tracked down the core of the problem - I
think.

We are using NFS mounted home directories - and the combination DIMAP +
NFS mounted home directories seems pretty bad. I ran a few tests and on an
account with 81MB mail spread over 90 folders, I could see a factor 10(!)
speed-up when using an account with a local home directory compared to one
with an NFS home directory. It looks to me like DIMAP is very badly suited
to such an environment, as it causes far too much traffic in the home
directory - I should have considered this earlier, especially, as it is
not possible to configure DIMAP/IMAP on a folder by folder basis. I will
definitely try to optimise our NFS setup further, but it looks like I'll
have to recommend to some users to use the "double account (one DIMAP, one
IMAP)" workaround - which, unfortunately, also has some major drawbacks
(no way to use the subscribe function in the IMAP account, hence even
folders one does not want to see are visible; in addition, unsubscribed
folders do not show up in Squirrelmail, so one has to
re-subscribe/unsubscribe every time one is using Squirrelmail[0])

I'm fully aware that some of these problems are due to lack of developer
ressources, but I decided to post these experience so people who are
testing the Kolab setup (which I very, very much like otherwise) have
another aspect to consider.

Best regards,

Thomas

[0] maybe there is a way to get Squirrelmail to show all folders
regardless of subscription - I'm still investigating.