Operating Systems in Memory (I Wonder...)

[David Ash]

David Lloyd wrote:
> 
> I'm about to buy myself my Christmas present (a Intel E6300 Core 2 Duo) 
> and it seems that I could stack 4Gb of memory into it. It strikes me 
> that for the genrally read only parts of an operating system, you could 
> stack most of that into a write through memory file system and still 
> have memory left over...
> 
> It would go something like this:
> 
> 1. Boot machine
> 2. Copy /usr, /opt into "memory file system"
> 3. Intercept file system calls to look at memory file system
>    - if read, read from memory
>    - if a write, write to memory then write to disk
> 
> Does this sound crazy or am I onto something?

You'll probably find the kernel already kind of does this with disk 
caching.  One article that kind of explains this:
http://kbase.redhat.com/faq/FAQ_80_705.shtm

But sounds like you want quick access from the first read, in which case 
you may want to consider "solid state disks", or those pci cards with 
ram sticks which act as a disk.  I haven't used either though.  Solid 
state disks aren't good for lots of writes etc.

Regards
Dash