Coda File System

Re: RVM metadata & VM

From: Jan Harkes <>
Date: Tue, 11 May 2004 16:19:17 -0400
On Tue, May 11, 2004 at 12:18:57PM -0400, wrote:
> Suppose I wish to set up a large coda volume -- say, 2Tb. With the
> 4% rule, this means an 80Gb partition for the RVM metadata. The 
> "Coda File System User and System Administration Manual" says
>     Virtual memory. The metadata, held in the RVM data file, is memory mapped.
>     You need that amount of space as virtual memory on your system, in
>     addition to virtual memory to run the server (~6MB) and other software.
> Does this mean that I need an *additional* 80Gb of swap space? That seems
> *bizarre.* (Considering that the target machine has probably 1-2Gb of RAM.)

I don't know what kind of computer you have, but 32-bit machines don't
have more than 4GB addressable address space for a given process. And
large parts of this are unusable because they are reserved for the
kernel (upper GB?), used by shared libraries, process heap and stack,

You can probably only get away with a maximum of 2GB of RVM data for a
given server process.

Received on 2004-05-11 16:23:53