Coda File System

some thoughts and questions

From: Ivan Popov <>
Date: Sun, 9 Mar 2003 12:17:26 +0100 (MET)

I am doing "brain surgery", as Jan calls it, on my Coda
servers - moving and resizing the RVM storage.

The process takes some time and gives an occation for thinking.

RVM is probably very efficient at the access, as all data resides in
(virtual) memory when you need it.

On the other side, rvm has its limitations that influence Coda too.

May be these limitations will become unnoticeable as soon as we move on
to 64-bit platforms, but for the moment rvm is heavily dependent on the
underlying OS memory allocation policies and an application using rvm
may suddenly break when you upgrade the OS or a library.

(the reason is that rvm is mapped onto a fixed address range in memory,
instead of relying on malloc() for finding an available area)

Even if we'd solve the allocation policy problem, the size of the database
contained in rvm pushes the limits of the whole available virtual memory,
on 32-bit platforms.

So my question is - how much would have to be rewritten to be able to use
some other database, allowing the same persistency and resilience,
hopefully comparable performance, but not dependent on mapping the whole
data in memory at once.

Best regards,
Received on 2003-03-09 06:19:11