Annotation of embedaddon/ntp/html/hints/a-ux, revision 1.1.1.1
1.1 misho 1: -------------
2: INTRODUCTION:
3: -------------
4: Last revision: 06-Jul-1994
5:
6: Included in this distribution of XNTP V3 is a configuration file suitable
7: for use under Apple's A/UX Version 3.x.x There is also one for A/UX 2.0.1
8: but it has not been fully tested. To make the executables follow the steps
9: outlined below.
10:
11: *** NOTE: You must have gcc installed to successfully compile the current
12: distribution; the native cc supplied with A/UX will NOT correctly compile
13: this source. See the FAQ in comp.unix.aux for places to obtain gcc from
14: and how to install it.
15:
16: ----------------------
17: MAKING XNTPD FOR A/UX:
18: ----------------------
19:
20: First, you need to create the makefiles (after you've downloaded the
21: source, of course):
22:
23: % make clean
24: % make refconf
25:
26: After that, you should edit Config.local to make sure that BINDIR is
27: correct for where you wish the programs to be "installed". The default
28: (and what I use) is /usr/local/etc. Make sure that DEFS_LOCAL and
29: CLOCKDEFS are commented out! Presently, only the LOCAL_CLOCK/REFCLOCK
30: clock is used and supported.
31:
32:
33: After this is done (you should be told that your system is A/UX 3), make
34: 'xntpd' (the options to 'gcc' are held in compilers/aux3.gcc):
35:
36: % make
37:
38: I do not normally use the `make install' option and so have not verified its
39: compatibility with A/UX. Rather, I pull out each of the executables and
40: place them in the locally appropriate locations.
41:
42: ---------------
43: STARTING XNTPD:
44: ---------------
45:
46: At this point you need to set things up so that 'xntpd' is started upon
47: boot-up. You can do this in 1 of 2 ways: either add entries in /etc/inittab
48: or, more ideally, create and use an /etc/rc.local file. Since rc.local is
49: what I recommend, here's how you do it:
50:
51: By default, A/UX doesn't have rc.local, so you'll need to add the following to
52: /etc/inittab:
53:
54: net6:2:wait:/etc/syslogd # set to "wait" to run a syslog daemon
55: + jmj0:2:wait:/etc/rc.local 1>/dev/syscon 2>&1 # Local stuff
56: dbg2::wait:/etc/telinit v # turn off init's verbose mode
57:
58: Now, the look of a sample /etc/rc.local is as follows:
59:
60: #!/bin/sh
61: :
62: : rc.local
63: :
64: # @(#)Copyright Apple Computer 1987 Version 1.17 of rc.sh on 91/11/08 15:56:21 (ATT 1.12)
65:
66:
67: # Push line discipline/set the device so it will print
68: /etc/line_sane 1
69: echo " "
70: echo "Entering rc.local..."
71:
72: set `/bin/who -r`
73: if [ "$7" = 2 ]
74: then
75: /bin/echo " now setting the time..."
76: /usr/local/etc/ntpdate -s -b <host.domain>
77: sleep 5
78: #
79: # start up 'xntpd' if we want
80: #
81: if [ -f /etc/ntp.conf ]
82: then
83: /bin/echo " setting tick and tickadj..."
84: /usr/local/etc/tickadj -t 16672 -a 54
85: sleep 5
86: /bin/echo " starting xntpd..."
87: /usr/local/etc/xntpd <&- > /dev/null 2>&1
88: sleep 5
89: fi
90: #
91: fi
92:
93: echo "Leaving rc.local..."
94:
95: There are a few things to notice about the above:
96:
97: o When run, 'ntpdate' forces your clock to the time returned by the
98: host(s) specified by <host.domain> (you'll need to replace this
99: be the IP address(es) of your timehosts. This is good since it gets
100: things close to start off with. You can use more than one time
101: server.
102:
103: o 'tickadj' is also called. This does two things: changes the
104: default value of 'tick' (which the the amount of time, in ms, that
105: is added to the clock every 1/60 seconds) and changes the value
106: of 'tickadj' which the the amount that is added or subtracted
107: from 'tickadj' when adjtime() is called.
108:
109: Now Mac clocks are pretty bad and tend to be slow. Sooo, instead of
110: having A/UX add the default of 16666ms every 1/60th of a second, you
111: may want it to add more (or less) so that it keeps better time. The
112: above value works for me but your "best" value may be different and
113: will likely require some fooling around to find the best value. As a
114: general rule of thumb, if you see 'xntpd' make a lot of negative clock
115: adjustments, then your clock is fast and you'll need to _decrease_
116: the value of 'tick'. If your adjustments are positive, then you need
117: to increase 'tick'. To make a guess on how fast/slow your clock is,
118: use 'ntpdate' to sync your clock. Now watch 'xntpd' and see how it
119: operates. If, for example, it resets your clock by 1 second every 30
120: minutes, then your clock is (1/(30*60)) is about 0.056% off and you'll
121: need to adjust 'tick' by 16666*0.00056 or about 9 (i.e. 'tick' should
122: be ~16675 if slow or ~16657 if fast)
123:
124: A/UX's default value of 'tickadj' is 1666 which is too big for
125: 'xntpd'... so it also needs to be adjusted. I like using larger
126: values then the recommended value of 9 for 'tickadj' (although not
127: anything near as big as 1666) since this allows for quick slews
128: when adjusting the clock. Even with semi-large values of 'tickadj'
129: (~200), getting 5ms (1/200 s) accuracy is easy.
130:
131:
132: Finally, before A/UX and 'xntpd' will work happily together, you need to
133: patch the kernel. This is due to the fact that A/UX attempts to keep the
134: UNIX-software clock and the Mac-hardware clock in sync. Neither the h/w or
135: the s/w clock are too accurate. Also, 'xntpd' will be attempting to adjust
136: the software clock as well, so having A/UX muck around with it is asking
137: for headaches. What you therefore need to do is tell the kernel _not_ to
138: sync the s/w clock with the h/w one. This is done using 'adb'. The
139: following is a shell script that will do the patch for you:
140:
141: #! /bin/sh
142: adb -w /unix <<!
143: init_time_fix_timeout?4i
144: init_time_fix_timeout?w 0x4e75
145: init_time_fix_timeout?4i
146: $q
147: !
148:
149: This must be done _every_ time you create a new kernel (via newconfig or
150: newunix) or else 'xntpd' will go crazy.
151:
152: --------
153: HISTORY:
154: --------
155:
156: John Dundas was the original porter of 'xntpd' and a lot of the additions
157: and A/UX-ports are from him. I got involved when I wanted to run 'xntpd'
158: on jagubox. It was also around this time that the base-patchlevel of
159: 'xntpd' changed relatively (the so-called "jones" version). Since then,
160: I've been maintaining 'xntpd' for A/UX for the xntp development team
161:
162: The original kernel patch (which patched 'time_fix_timeout') was from
163: Richard Todd. I suggest patching 'init_time_fix_timeout' which prevents
164: 'time_fix_timeout' from even being called.
165:
166: ----------------
167: TECHNICAL NOTES:
168: ----------------
169:
170: o As configured (see machines/aux3), 'xntpd' will log messages via syslogd
171: using the LOC_LOCAL1 facility. I would suggest the following in
172: /etc/syslog.conf:
173:
174: local1.notice /usr/adm/ntpd-syslog
175:
176: o As mentioned above, the clocks on A/UX and Macs are kinda bad. Not
177: only that, but logging in and out of the MacOS mode as well as
178: extensive floppy use causes A/UX to drop and lose clock interupts
179: (these are sent every 1/60th of a second). So, if you do these
180: activities a lot, you find out that you lose about 300ms of time
181: (i.e., you become 300ms slow). 'xntpd' default way of handling this
182: is to called 'settimeofday()' and step the clock to the correct
183: time. I prefer having 'xntpd' slew the clock back into line by
184: making gradual adjustments to the clock over a coupla minutes
185: or so. It's for this reason that SLEWALWAYS is defined in
186: include/ntp_machine.h for SYS_AUX3. It's also for this reason than
187: I like larger values of 'tickadj'.
188:
189: Good luck! If you have problems under A/UX feel free to contact me (e-mail
190: is preferred).
191: --
192: Jim Jagielski | "That is no ordinary rabbit... 'tis the
193: jim@jagubox.gsfc.nasa.gov | most foul, cruel and bad-tempered
194: NASA/GSFC, Code 734.4 | rodent you ever set eyes on"
195: Greenbelt, MD 20771 | Tim the Enchanter
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