NTPD howto?
in [Linux Networking]
|
Prev: 7 second pause when writing file using samba before it is read via NFS
Next: How to exclude MULTIPLE directories in a rsync command ?
From: Jack Snodgrass on 6 May 2008 05:05 I can't figure ntpd out. I've got it configured ( using the defaults ) on a fedora 8 box. It starts and runs... it just doesn't keep my non-stable-clock system up to date. If I let my vmware guest run for 24 hours, the time on the vmware guest gets off by about 2 hours. Currently, I have ntpd disabled and I have a cron job that runs every minute and runs ntpdate to keep the time accurate... I thought that ntpd was supposed to be able to do this.... If ntpd can't keep the time on the local box accurate... what's the purpose of it? I've had this issue with ntpd for years... I've always had to resort to disableing it and running ntpdate from cron. Thanks - jack -- D.A.M. - Mothers Against Dyslexia see http://www.jacksnodgrass.com for my contact info. jack - Grapevine/Richardson
From: Chris Davies on 6 May 2008 06:51 Jack Snodgrass <jacks_temp_id_blue62(a)verizon.net> wrote: > I can't figure ntpd out. > I've got it configured ( using the defaults ) on a fedora 8 box. > It starts and runs... it just doesn't keep my non-stable-clock system up > to date. If I let my vmware guest run for 24 hours, the time on the > vmware guest gets off by about 2 hours. OK. Stop there. You cannot use ntp reliably within a vmware environment and expect it to work [1]. Separate the two problem spaces and get NTP working on your real box, first. > Currently, I have ntpd disabled and I have a cron job that runs every > minute and runs ntpdate to keep the time accurate... That will never train your kernel to keep time reliably. Go back to running NTP and we'll work through the issues with you. For a start, after NTP has been running for several minutes (more than five), what does the output of "ntpq -p" give you? Chris [1] Actually you can, but you have to set the appropriate kernel flags and I strongly suggest you don't even think about going there until you've proven NTP works on your underlying hardware
From: Unruh on 6 May 2008 11:15
Jack Snodgrass <jacks_temp_id_blue62(a)verizon.net> writes: >I can't figure ntpd out. >I've got it configured ( using the defaults ) on a fedora 8 box. >It starts and runs... it just doesn't keep my non-stable-clock system up >to date. If I let my vmware guest run for 24 hours, the time on the >vmware guest gets off by about 2 hours. >Currently, I have ntpd disabled and I have a cron job that runs every >minute and runs ntpdate to keep the time accurate... >I thought that ntpd was supposed to be able to do this.... >If ntpd can't keep the time on the local box accurate... what's the >purpose of it? I've had this issue with ntpd for years... I've always >had to resort to disableing it and running ntpdate from cron. ntp has limitations. If your boxes clock has a huge drift ( above 500PPM) it cannot fix it. You have a drift of 100000PPM. ntp cannot fix it. You need new hardware. You simply have very very bad hardware. I have no idea what you mean "my vmware guest". ntp disciplines the harware clock on your physical system. It cannot do anything about a virtual system. The virtual system has no clock. You must run ntp on your physical system. >Thanks - jack >-- >D.A.M. - Mothers Against Dyslexia >see http://www.jacksnodgrass.com for my contact info. >jack - Grapevine/Richardson |