[Dovecot] outlook 2007 very slow.

[Ed W]

On 28/09/2011 21:00, Kui Zhang wrote:
> TB hangs on start up, for extent period of time. cpu at 100%, ram at 1
> - 1.2 GB used. CPU usage almost always at 100%. And it hangs from time
> to time. The client side disk usage for TB is around 200MB… why would
> it need 500MB of ram? This is something I will bring up with the
> thunderbird people.
>

If you care to debug in more detail, you may learn a lot by watching the
network traffic at this point?  You can setup debugging on the server
side, but personally I find this a touch hard to setup for one off
sessions (and shared IPs/mailboxes, etc).  Also consider wireshark and
just tracing a single machine.  The point being to see if it's locked up
because it's thrashing the mail server for some reason, or if it's doing
something silly client side?

Random untested ideas:
- I believe it pulls the folder list down at startup.  With thousands of
folders in your case (did I understand that?) you might find it's doing
some silly select on each folder and hence spending ages being bound by
the ping speed to the server (something like 100-200 round trips per sec
max I think you said?), or perhaps it's even worse than that if it
causes some disk seek for each folder?

- Quantity of headers could be large under certain circumstances - check
if you are network bandwidth bound?

- TB might be doing something silly locally and you are bound by disk
seek time on your local machine as it does whatever it does to several
thousand mbox files? Move the TB local folder to some slower/faster disk
and observe if the startup speed gets proportionally slower/faster..? 
Eg I slapped in some large flash drive to my Mac and now I keep
forgetting that others still have seek time limitations starting apps...

Good luck - interested to hear if you can trace this to something?

Ed W


P.S.  I will try and post some tips in a new thread, but I found that TB
and other clever clients can benefit enormously if you turn on the
appropriate zlib stuff that means the COMPRESS extension is supported
(not on by default). Outlook hasn't historically supported this, so I
doubt it will help above, but it's one feature that can give TB the edge
over Outlook.