[Dovecot] blocked for xx secs

Hello,

Occasionally (a few times a day) we get batches of Warnings in the log such as: dovecot: Warning: chdir(/maildir/x.co.uk/users/y) blocked for 18 secs This tends to last a minute or so for different users.

/maildir is a NFS mount, and I'm suspecting it's the NFS server being busy and dovecot having to wait.

Other than replacing the NFS server with faster hardware is there anything else we can do?

Indexes are local, and Maildir is on the NFS.

Dovecot 1.2.5 using: mail_nfs_storage = yes mmap_disable = no

NFS mounted as; /maildir on /.automount/a.diskless/root/mail type nfs (nosuid,nodev,noatime,vers=3,proto=tcp)

TIA

Andrew