Tuning for PostGreSQL Database

Sean Chittenden sean at chittenden.org
Tue Jul 22 11:55:28 PDT 2003


> > You might want to get in the habit of using sysctl for getting
> > that kind of info.  `sysctl -d vfs.bufspace`
> 
> I'm confused.  Everything I have ever read about FreeBSD indicates
> that it uses all free ram for the disk cache.

>From loader(8):

     kern.maxbcache
                   Limits the amount of KVM reserved for use by the buffer
                   cache, specified in bytes.  The default maximum is 200MB.
                   This parameter is used to prevent the buffer cache from
                   eating too much KVM in large-memory machine configurations.
                   Only mess around with this parameter if you need to greatly
                   extend the KVM reservation for other resources such as the
                   swap zone or NMBCLUSTERS.  Note that the NBUF parameter
                   will override this limit.  Modifies VM_BCACHE_SIZE_MAX.

-sc

-- 
Sean Chittenden


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