Subject: Re: Where do cron tabs belong?
To: No Spam <vex!qiclab!sopwith.UUCP!nospam@fundy.ca>
From: David Maxwell <david@fundy.ca>
List: current-users
Date: 04/21/1999 23:53:47
On Wed, Apr 21, 1999 at 02:52:51PM +0100, No Spam wrote:

Good, a nice summary of points. I'll try to leave it
mostly intact.

> 	Things that are not needed in single-user mode do not belong
> 	in the root filesystem.

Needed is tricky. I'd say there's lots of things there now that
aren't 'needed'. 

> 	Things that generate disk writes should not be moved
> 	into the root filesystem.

With what freqency/scale?

> Curt Sampson writes:
> One can look at this from various points of view, but it is
> rarely a clean split:
> 
> 	Cron tabs contain system configuration kinda stuff *and* user
> 	data kinda stuff.

I continue to contend, so do passwd files.

> 	In some environments you want cron tabs to be read-only,
> 	in others you want them read-write.

chflags as needed, wherever they may be.

> 	Some stuff in /var should be backed up, some
> 	doesn't need to be.
> 
> 	Cron tabs contain config info, so they should be in /etc.
> 	Cron tabs vary, so they should be in /var.

They don't vary in my definition of 'var'. To me, /var contains
data that varies a lot. I'd suggest that for most users cron
changes once every 4 months (avg), while /var/mail changes
hourly.

> I see two arguments for moving cron tabs from /var to /etc:
> 
> 	To allow not backing up /var.
> 
> 	Cron tabs contain config data, and thus belong in /etc.
> 
> If /var is too large to back up reasonably, it is easy enough
> to have your backup script tar (or whatever) /var/cron/ off
> to tape, or put a tarball on a filsystem that does get backed up.
> This is site specific, plenty of sites do back up /var.
> 
> Crontabs also contain user data, and so don't belong in /etc.

I don't accept that that overrides the arguement. It has been 
noted that crontabs should be 'system controlled' user-data,
both for purposes of limiting space usage, and for alerting
users to errors before they log out, expecting their job to
work properly.

> Thus I feel that the arguments for moving cron tabs from /var to
> /etc are fairly weak, and greatly outweighed by the arguments against,
> such as writes to the root filesystem.

To me, this is much weaker than the 'user-data' argument against
moving to /var. Can anyone reference more than one system
where they see frequent cron file updates? As I say, I'd guess
4months -> forever between changes for the most part. People
probably change their password more often than their crontabs.

> If you have partitions to spare, there other possible setups to consider,
> such as:
> 
> 	have a /etc/multiuser partition, and have cron tabs be
> 	in /etc/multiuser/cron/tabs/

Nor have more spaces to run out of disk space. Many non-server
installs are simpler to maintain with just a single '/'
partition. Do many people here feel that's taking a bit risk
with filesystem lossage? Perhaps the case if we were running
EXT2FS instead of FFS... but we aren't. (most of us)

-- 
David Maxwell, david@vex.net|david@maxwell.net --> Mastery of UNIX, like
mastery of language, offers real freedom. The price of freedom is always dear,
but there's no substitute. Personally, I'd rather pay for my freedom than live
in a bitmapped, pop-up-happy dungeon like NT. - Thomas Scoville