On Thu, 2010-09-02 at 09:47 -0400, Charles Marcus wrote: > On 2010-09-02 9:08 AM, Cor Bosman <c...@xs4all.nl> wrote: > > NFS has a problem where caching of the files > > can cause each imap server to see outdated information. Server 1 could > > have just written some updates into the index file, but Server 2 doesnt > > see this yet, and writes conflicting data into the index file. > > Just curious, but is there no way to just disable the caching on the NFS > share where the indexes are stored?
Disabling attribute caching solves most of this, but increases the NFS traffic by 10x or so (and still isn't perfect). Dovecot v1.1 added a setting where it tried to flush the NFS cache only when necessary. It worked better than nothing, but not perfectly. I tried fixing it for a long time, spent a lot of time reading Linux and FreeBSD NFS kernel code and writing test programs, trying to get Linux to fix some things .. then I finally gave up.
