guru input needed! (re-inventing disk quotas)

[Douglas J Hunley]

Morning all:
	I have a client that wants to migrate to Linux from Solaris, but one of their 
main "gotchas" is the quota support in Linux. They believe (as do I) that 
quotas seem to be the first thing broken (and the last thing fixed) whever a 
change is introduced into the fs or block layers of the kernel. They 
currently have a *very* detailed accounting system in place that charges 
their internal customers (departments) based on disk usage, CPU usage, 
network utilization, etc. They don't want to lose any of this when they go to 
Linux. I believe I have solutions for everything but the disk quotas. 
However, I have what I think is a neat idea for solving the disk issue. I 
would like opinions.
	What I propose is this:
1. create /loops on the main disk server
2. for each user on the system, use 'dd' to preallocate a file in /loops:
	dd if=/dev/zero of=/loops/joe bs=1k count=10240
   which would create a 10M (if my math is right) file called /loops/joe
3. chown joe:users /loops/joe
4. configure the automounter to mount the newly allocated file as joe's $HOME
	mount -o loop /loops/joe /home/joe

Obviously, I would have to create a local 'create user' script to allocate the 
file, and add the entry into the automounter config.

The biggest caveat I can see is that "joe" would be charged for 10M even if he 
only used 2M. I already ran this concerns by them, and they seemed OK with 
it. They said they would be happy selling disk in chunks like this. And we 
could always "extend" the allocation be creating a joe2 of the new size, and 
then copying the contents over and moving joe2 over top of joe.

This will free them from worrying about whether or not the current quota code 
is working properly, and would easily enforce the hard limit. (there's no way 
that joe could write 11M of stuff. he'd get ENOSPACE).

Thoughts?
-- 
Douglas J Hunley (doug at hunley.homeip.net) - Linux User #174778
Admin: Linux StepByStep - http://www.linux-sxs.org
	and http://jobs.linux-sxs.org

You're not paranoid.
The world _IS_ fscked.