Michele Bensi¹, Stefano Barberis², Massimo Mezzadri², Francesco Prelz²

1) Università degli Studi di Milano, 2) INFN Sezione di Milano

The storage of user email boxes on a shared filesystem and their read/write access on multiple cluster nodes requires special care to benefit from file persistence in the filesystem cache on each node and to prevent system response to be significantly degraded by frequent file synchronisations onto physical storage. The simplest measure towards this goal is to divide access to nodes on a peruser basis, while keeping the cluster failsafe. In this paper we share a few nonobvious details for the configuration of such user/node affinity in sendmail, dovecot, squirrelmail.