[Dovecot] NFS random redirects

[Thomas Hummel]

On Mon, Oct 19, 2009 at 12:42:08PM -0400, Timo Sirainen wrote:

Thanks for the answers Timo,

I understand random redirect is not a good idea but I'm trying to evaluate the
damage it can do.

> If you do it, you'll most likely see some random index related errors.

But are index related errors recoverable (does dovecot notice and fix it
dynamically ?) or will they cause client-side corruption ? 

How bad would that corruption be ? (like fetching wrong message, since index
store nextuid as well ? setting wrong flag ? ...) and how could a client fix it ?

> caches.. So I've added some highly OS-specific code that works most of  
> the time, but not perfectly. It works best with Linux.

Ouch! I run dovecot on FreeBSD ;-(

> imaptest exists now in http://imapwiki.org/ImapTest

Thanks. Sorry I didn't find it. Do you have any suggestion to test specifically
nfs corruption chances ?

> Actual mail content should be safe. Unless you just happen to get such  
> a cache file corruption that Dovecot doesn't notice it and sends some  
> broken headers to IMAP client.

If that happened, with Maildir, the actual content on disk on server wouldn't
be corrupted I guess, so I would that be recoverable on the client ?

> The long term fix for this is http://www.dovecot.org/list/dovecot/2009-August/041983.html

Thanks.

-- 
Thomas Hummel 	    | Institut Pasteur
<hummel at pasteur.fr> | Pôle informatique - systèmes et réseau