Subject: Re: Abusing NFS+UNIONFS to avoid BSDOBJDIR.
To: Todd Whitesel <toddpw@best.com>
From: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
List: current-users
Date: 07/02/1999 23:01:03
At 9:35 Uhr +0200 02.07.1999, Todd Whitesel wrote:
[...]

>    3. The client machines all NFS-mount the source read-only, and union
>	mount local storage on top of it.
>
>    4. The client machines build -current inside their union mounts,
>	without using BSDOBJDIR.
>
>Barring bugs in UNIONFS, it seems to me that this method should work.
>Of course I have to be careful about local files obscuring changes
>brought in by SUP, but that's a manageable nuisance.

I use this pattern fairly regularly for builds, exporting the supped tree
from a Mac IIci and building on a Quadra 700. For all I can see you should
be safe as long as

o  you properly unmount the union mounts before shutdown (when a cwd is in
the union-mounted tree your box will hang)

o  avoid several processes exercising the tree simultaneously (e.g. disable
/etc/daily during the builds).

As long as I avoid the well-known weak spots, unionfs is pretty workable
for me - sort of poor man's version control.

	hauke


--
"It's never straight up and down"     (DEVO)