Miserable performance of cyrus-imapd 2.3.9 -- seems to be lockingissues

[Rob Mueller]

> but all attempts to simulate
> a client load-pattern are devilishly difficult to get right.

I can atest to this as well.

I created an "imapstresstest" tool a few years back to attempt to stress our 
cyrus installs. It attempts to emulate all the main actions of a running 
IMAP server like lots of IMAP connections (>1000) with 
status/select/fetch/copy/create/rename/delete commands, and lots of LMTP 
email deliveries, etc. I used to be able to generate reasonable loads, but 
it never was quite the same as what actual users would do to the system.

As an FYI on RAID controllers, we've used ARECA controllers 
(http://www.areca.com.tw) and they've been excellent in RAID-1, RAID-5 and 
RAID-6 modes. They include up to 1G of battery backed up cache.

Rob