[nylug-talk] fun with fstab, bind and unionfs

[jh]

I'm trying to use things like bind and unionfs to work around the silly 
things that commercial software vendors do. These silly things become 
problems in a diskless environment :( And sadly, no, I don't have the 
option of finding sane vendors in their product classes.

First issue: a bind mount solves one issue that I'm having with one 
vendor (who needs writable access into subdirectory of /opt). I have 
this entry in my fstab:

/Sillyvendor /opt/Sillyvendor none rw,bind 0 0

If I manually issue the command

mount /opt/Sillyvendor

it works fine. But it doesn't mount at boot time. Can someone shed some 
light on this? I guess that I could put something in rc.local, but it 
should work from fstab, no?

Second issue: I have a very, very silly vendor that insists on having 
write privs to /usr. Sadly, my diskless boxes don't allow this.

I thought that unionfs might be the solution. Any suggestions on how to 
do this, especially from fstab? I was thinking of something like this... 
not sure how to do a unionfs entry in fstab...

foo:/usr /usr_temp nfs ro,hard,intr 0 0
none  /usr  unionfs dirs=/usr_temp:/usr_write 0 0

Any comments on whether this would work, or perhaps, on the fine points 
of unionfs?

Thanks.

jh