Subject: Re: Solution(?) to kern/28804: quotacheck crashes on FFSv2
To: NetBSD Kernel Technical Discussion List <tech-kern@NetBSD.org>
From: Greg A. Woods <woods@weird.com>
List: tech-kern
Date: 02/22/2007 13:53:53
At Tue, 20 Feb 2007 04:59:54 +0700,
Robert Elz wrote:
> 
> ps: I'm not sure that quotas make much sense on most systems regardless
> of snapshots any more - they were designed in the days when hundreds
> of users were sharing tens (or maybe small hundreds) of megabytes of
> file system space, not when single (or very small numbers) of users
> have hundreds of gigabytes available.

We're using quotas as a tool to implement a revenue generating policy
for web server users and of course the policy is also partly there in an
attempt to avoid certain kinds of abuse through proactive controls.

The advantage of filesystem quotas is that they do allow easy
implementation of hard and fast technical controls for such policies.

The only big disadvantage of quotas is that it takes too long to run
quotacheck after a crash.  I wish it could be run in the background on a
live filesystem where quotas are already turned on, but unless I'm
mistaken that won't work even on FFSv2 (never mind the risk that the
quota file might be dangerously corrupted after a crash too).

Unfortunately the ~18,000 users aren't buying more space than they're
allotted, or even using much of what they can:

$ df -mi /home
Filesystem  1M-blocks     Used    Avail %Cap    iUsed  iAvail %iCap Mounted on
/dev/sd7a      712380     3764   701492   0%    95360 45869438   0% /home

but that's more likely because they're almost all neophytes when it
comes to WWW publishing and often technology in general.  :-)

-- 
						Greg A. Woods

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Planix, Inc. <woods@planix.com>       Secrets of the Weird <woods@weird.com>