El 04/07/12 23:55, Timo Sirainen escribió:
On 4.7.2012, at 21.49, Angel L. Mateo wrote:
Although nfs configuration is the same, there are a lot of differences on readdir vs readdirplus nfs operations. In fact, in the old one we have 12% readdir operations and 3% of readdirplus. And in the new one we have 46% of readdirplus and no readdir operations.
I'm not entirely sure, but I think it's the kernel that decides if readdir or readdirplus is used and Dovecot can't affect that decision. (Unless maybe kernel does some heuristics.)
I think you are right. I guess that the differnce between my old system (who uses readdir and readdirplus) and the new one (which just uses readdirplus) is because of changes on the kernel. For some threads I have read (for example, http://www.spinics.net/lists/linux-nfs/msg19957.html) it seems that from some version in kernel source (2.6.36 if I remmeber well) some nfs improvements related with readdir and readdirplus (that makes nfs client only uses readdirplus when it was better) and recents kernels always use readdirplus.
Concluding... in my systems, with users with hugh mail folders (thousands of mails) in maildir format, disabling rdirplus with mount options (mount option nordirplus) increases performance (maybe we could do more precise test and this could be documented in dovecot's nfs documentation)
-- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información y las Comunicaciones Aplicadas (ATICA) http://www.um.es/atica Tfo: 868887590 Fax: 868888337