Optimising pxeboot disk size

[Wojciech Puchar]

>> it's simple:
>
> More simple when you tell it ;-) Thanks a lot, i will try it tonight !

it doesn't have chance - must work :)

>
>> I wish it's helpful, doing this doesn't just save space but saves time - 
>> you have to upgrade software once.
>
> So preserving consistency, which is the most important when you have lot of 
> diskless stations !

exactly. i'm using just NetBSD 1.5 (uses LITTLE memory) + Xserver, so 
there are almost no updates, but anyway - it's stored once.

>> you may like to make /etc-common directory and put most of files there, and 
>> symlinks in each station's /etc
>
> In fact, it makes me think that we miss a concept in mount, or at least i 
> don't know it currently :
> imagine a -tl (TransparentLayer) option for mount, allowing to mount multiple 
> source to the same directory, for instance /etc :

there is already such think - mount_unionfs

but i don't use it.

if you mount over some directory - it's original contents (like my /etc/rc 
doing exec /systemrc) gets hidden.

>
> mount -r yournfsserver:/basic/etc /etc
> mount -tl -r yournfsserver:/TypeX/etc /etc
> mount -tl -r yournfsserver:/StationY/etc /etc

mount_unionfs

but i don't know how stable it is.

> When you want to change something, you add a rw TransparentLayer :
> mount -tl yournfsserver:/StationYchanges/etc /etc
>
> So that changed or added files are only stored in this rw partition, thus 
> very small and easy to manage.
>
> This would be a kind of partition inheritance, like in object languages... 
> Dreams are allowed :-)

try mount_unionfs