cyrus, postfix and NFS

[Pierre Chifflier]

Hi,

I am currently trying to gather informations on the cyrus vs NFS
situation. I'm sorry if this has been asked several times on the mailing
list, what I need is some details, to understand correctly the situation
and evaluate the viability of some projects.

The FAQ and some messages mention that it is unsafe, for ex:
http://www.irbs.net/internet/info-cyrus/0503/0238.html
http://kolab.org/pipermail/kolab-devel/2005-July/004033.html

As I understand, there are two problems:
* using locks is unsafe on NFS, especially for db files
* some problems with mmap

It seems that recent changes (say, last 4-6 months) in the linux kernel
have been made to try to solve this problem.

Some informations:
- linux/debian etch (kernel 2.6.18)
- postfix (2.3) + cyrus-murder + cyrus imap (2.2.10)
- backend would be connected to a NAS. It could get up to 10k IMAP
  connections (simultaneous), while the postfix could receive 500k mails
  per day

So, here are my questions:
- did the situation change ?
- is it possible to know precisely if a backend will work or not with
  NFS ? Known working (or not-working) situations ?
- is there a way to avoid the problem, or to test if it is still
  present ?

Thanks

Regards,
Pierre