cyrus, postfix and NFS

[Simon Matter]

> 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 ?

There has been some discussion about using NFSv4 with cyrus on this list
recently. At least on Linux I think nobody had success, and we are still
waiting to test with a current Solaris version. Maybe someone tried it in
the mean time and is able to report.

Simon