Subject: Re: [netatalk-admins] DIDs - an idea -or- I didn't read the AFP specs completely yet

From: "Donald L. Nash" <[email-masked]>
Date: Wed, 15 Apr 1998 16:57:31 -0500

--On Wed, Apr 15, 1998 4:44 PM -0500 "Andrew McNabb"
<[email-masked]> wrote: 

> What happens if you change your system clock (esp. dailylight savings)?

Unix clocks tick GMT, so that isn't a problem.

> Also, what if you have two files created during the same second (not
> unlikely if you have a big system).

You would need to have two *directories* created during the same second,
which is more rare but a problem nevertheless.  The .maxDID or .DIDdb ideas
fix that problem, and the race condition that Incze mentioned can be fixed
with file locking.

-- 
Donald L. Nash, <[email-masked]>, PGP Key ID: 0x689DA021
The University of Texas System Office of Telecommunication Services
PGP Key Fingerprint: D6D2 CBEE 8F56 60B2  736C 031A A1E0 AF3D

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From: Andrew McNabb <[email-masked]>
Date: Wed, 15 Apr 1998 17:05:06 -0500 (CDT)

> Unix clocks tick GMT, so that isn't a problem.

I guess dailylight savings wouldn't be a problem because of GMT, but
people still change system clocks because PCs invariably deviate quite
quickly.

----------------------------------------------
                Andrew McNabb
             Argus Systems Group
          [email-masked]
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  I am an International Arms Trafficker!!!!!
http://online.offshore.com.ai/arms-trafficker/
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From: Robert Beer <[email-masked]>
Date: Thu, 16 Apr 1998 08:57:32 -0400

>people still change system clocks because PCs invariably deviate quite

I don't understand all of the technical subtlties, but while you are
talking about clock changes what about the action on xntpd and the
adjustments it makes to keep correct time.  Just a thought.

---
Bob Beer <[email-masked]>
Ohio Northern University, Academic Computer Services, Ada, OH  45810

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From: William LeFebvre <[email-masked]>
Date: Thu, 16 Apr 1998 09:21:16 -0400

> adjustments it makes to keep correct time.  Just a thought.

xntp does its thing by slewing the clock (not explicitly setting it).
Speifically, it calls "adjtime" which tells the kernel to speed up or
slow down the time clock for a period of time.  See "man adjtime" for
details.

				William LeFebvre
				Group sys Consulting
				<[email-masked]>
				+1 770 813 3224