Tuning for PostGreSQL Database

Michael Conlen meconlen at obfuscated.net
Tue Jul 22 12:19:42 PDT 2003

Sean Chittenden wrote:

>>>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.

Aren't we talking about two different things here, the buffer cache and 
the inactive pages?

Michael Conlen

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