IMNSHO:
Not to start a flame war, but we've all been hearing about how
cheap disk is for a long time. Remember to add in the costs related to
disk installation and management. These are forgotten truths:
* time to research for purchase
* time to negotiate and purchase
* time to physically install
* cost to provision power, cooling and SPACE (these can really add up)
* time for initial configuration
* optional cost for RAID software (Veritas?)
* time/hardware/software costs for expanded backups (high cost item)
* time for on-going monitoring and management
--------------------------------------------------
= a liberal disk policy is not cheap and can actually be quite costly
It is a bad idea to convice users that the sky is the limit,
because they will defy science in short order and find it.
Brian
======================================================================
On Fri, Aug 09, 2002 at 01:10:45PM -0400, Jeff A. Earickson wrote:
> Hi,
> IMHO, quotas on mail file systems are a bad, bad idea. You don't ever
> want to loose email because a file system filled up or a user hit their
> quota (something they can't control if they aren't around to check email).
>
> Disk is cheap, buy more if your mail spool starts filling up. I use
> a 8 GB mail spool for 3000 users (with another 8+ GB in reserve). During
> the worst time in the summer when the students are gone, it will get about
> 30% full. If it ever gets to 50% full, I will add more disk.
>
> For those POP users who insist on using the "leave mail on server" option,
> I have a perl script that will read a standard mbox format file and delete
> messages based on different criteria (I didn't write the script). I run
> a cron job every week that deletes any message that has been opened for
> reading AND is more than 30 days old. This keeps the old drek cleaned
> out of the mail spool. The user community knows about this policy.
>
> ** Jeff A. Earickson, Ph.D PHONE: 207-872-3659
> ** Senior UNIX Sysadmin, Information Technology EMAIL: [EMAIL PROTECTED]
> ** Colby College, 4214 Mayflower Hill, FAX: 207-872-3076
> ** Waterville ME, 04901-8842
> ----------------------------------------------------------------------------
>
> ---------- Forwarded message ----------
> Date: Fri, 9 Aug 2002 12:53:18 -0400
> From: "Alan W. Rateliff, II" <[EMAIL PROTECTED]>
> To: Subscribers of Qpopper <[EMAIL PROTECTED]>
> Subject: Re: Filesystem quotas
>
> ----- Original Message -----
> From: "Michael Kolos" <[EMAIL PROTECTED]>
> To: "Subscribers of Qpopper" <[EMAIL PROTECTED]>
> Sent: Friday, August 09, 2002 9:17 AM
> Subject: Re: Filesystem quotas
>
>
> > What is this "boundary condition" and when does it come up?
> > We have the temp dir on a non-quota filesystem, and on the spool dir users
> > have a hard quota 100k more than the soft quota.
> > Yet we still occasionnally end up with a user with a corrupted mail spool
> > because somehow it went over quota, and when qpopper copies the spool
> back,
> > it gets corrupted.
> > I have tried turning off the X-UIDL writing, but that hasn't helped.
>
> Imagine a user with a 5120k hard quota, and 4.9MB in their mailfile.
> QPopper copies that mailfile over to the non-quota filesystem to POP it out,
> and while the user is checking his/her email (and apparently NOT deleting it
> from the server) they receive a 200k email. Now there's 200k in their
> mailfile, only 4.8MB available. The POP session is over and QPopper copies
> the .pop file back into the mail spool. 0.2MB + 4.9MB = 5.1MB > 5.0MB: the
> user is now over quota, and the last 100k or so is lost.
>
> That was my concern. But frankly, I don't like my users leaving their mail
> on the server. But that's not an entirely practical requirement when some
> people have multiple machines/people checking the same box (which I
> recommend multiple boxes with aliases) or using webmail as their primary or
> only mail viewing agent.
>
> But, that's what happens. I haven't decided if it would be nicer to have
> quota systems installed in the local mail delivery agent or not, as it would
> require a separate database of user quotas. I think procmail can do that,
> but I'm only beginning to learn about it.
>
> --
> Alan W. Rateliff, II
--
_____________________________________________________________________
/ Brian C. Hill [EMAIL PROTECTED] http://brian.bch.net \
| Unix Specialist BCH Technical Services http://www.bch.net |
