Re: [exim] Shared /var/spool/exim4/db

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Author: Tony Finch
Date:  
To: Craig Whitmore
CC: exim-users
Subject: Re: [exim] Shared /var/spool/exim4/db
On Sun, 12 Feb 2006, Craig Whitmore wrote:
>
> Is is safe to have a shared /var/spool/exim4/db (say have it on NFS) so I can
> share the callout and ratelimit db's etc on multiple machines


Not really - you're relying on NFS locking, which is only safe if you are
careful.

Note that this may hurt your performance, because the locking that Exim
uses to access the hints databases does not allow any concurrent access.
Thus if your NFS server can't keep up with the hints database load then
all your mail servers will be waiting for it rather than handling email.
Exim's speed is already limited by the hints databases on a single
machine, so on a cluster the problem will be worse.

Clustered hints databases require modifications to Exim:
http://fanf.livejournal.com/38006.html

Tony.
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