Re: Enhacement request - 'date' util
On Wed, 12 Aug 2009, Alejandro Redondo wrote: Well, the first clock set, when ntpd starts, is made in just one step. This can be a problem when the client host is several seconds different than the ntp server. Stepping versus slewing can be configured in ntpd. By default small time offsets are slewed, and large offsets stepped. In the example I suffered, I had to sync different flavors clients with the ntpd servers. Unluckily some of them had the ntpd daemon stopped for a lot of time and they had differences, to have an example, about 100secs (ntpdate -d ntp_serve used to know it). It was not a problem on solaris/hpux boxes to use the date -a 100.00 and then restart the ntpd daemon with the right config avoiding a 100secs jump in time. How fast does the kernel slew? A 0.5ms/s drift rate will fix 100s error in around 2.3 days; slewing is inappropriate for large corrections. If software can't tolerate backward steps in time then perhaps it's better to halt it while the system clock is fixed. (BTW, leap seconds make this hard.) These commands are better suited to altering the frequency of the system clock: ntpdate -B ntpd -g -q -x adjtimex --singleshot Cheers, Phil
Re: Enhacement request - 'date' util
Alejandro Redondo wrote: Hi again, sorry about those HTML characters... I sent the first email from a webmail client. And sorry about my bad English too, it's not my natal language. I didn't notice anything wrong with your English, actually :-). (Why is it, I wonder, that non-native speakers always assume their English is bad? ;-) Or do us native speakers simply not notice because /our/ English is equally bad? And I am serious about that, English is a notoriously abused language and there are /very/ few people that use it properly. I'm not one of them.) Well, the first clock set, when ntpd starts, is made in just one step. Ideally that should be at system startup, when nothing that would get confused is running yet ;-). -- Matthew Please do not quote my e-mail address unobfuscated in message bodies. -- ELANG: input is in wrong language (please use English on English lists)
Enhacement request - 'date' util
Good morning from Spain,first of all, thanks for your effort and for this rich featured tools... awesome work!Secondly, to the quot;datequot; command developers, it would be possible to develop the quot;-aquot; feature, like other UNIXes distros do?Man from solaris 10:-a [-]sss.fffnbsp;nbsp; Slowly adjust the timenbsp; bynbsp; sss.fffnbsp; seconds (fff represents fractions of a second). This adjustment can be positive or negative.nbsp; The system'snbsp; clocknbsp; isnbsp; spednbsp; up or slowed down untilnbsp; itnbsp; has drifftednbsp; bynbsp; thenbsp; numbernbsp; of secondsnbsp; specified.Man from hpux 11.23:-a [-]sss[.fff] Slowly adjust the time by sss.fff seconds (fff represents fractions of a second).nbsp; This adjustment can be positive or negative.nbsp; The system's clock will be sped up or slowed down until it has drifted by the number of seconds specified.Really useful feature to avoid crashes and dumps in apps like SAP or Oracle when changing time is needed.Thanks for your time,sincerelyAlejandro Redondo. _ This mail sent using V-webmail - http://www.v-webmail.org
Re: Enhacement request - 'date' util
Please use newlines and don't use HTML entities in text mail (or don't send HTML, if that was the problem). Your original mail looked like this: Good morning from Spain,first of all, thanks for your effort and for this rich featured tools... awesome work!Secondly, to the quot;datequot; command developers, it would be possible to develop the quot;-aquot; feature, like It is extremely difficult to read this block of text that has no newlines except where line wrapping occurred, is missing spaces between paragraphs, and is strewn with HTML entities. I have reformatted the relevant parts so that it is legible. Alejandro Redondo wrote: Secondly, to the date command developers, it would be possible to develop the -a feature, like other UNIXes distros do? Man from solaris 10: -a [-]sss.fff Slowly adjust the time by sss.fff seconds (fff represents fractions of a second). This adjustment can be positive or negative. The system's clock is sped up or slowed down until it has drifted by the number of seconds specified. Man from hpux 11.23: [snipped; same as above] Really useful feature to avoid crashes and dumps in apps like SAP or Oracle when changing time is needed. While that does indeed sound like an interesting option, and there is precedent of other OS's having it, I am curious why you don't just use ntpd? -- Matthew Please do not quote my e-mail address unobfuscated in message bodies. -- ESIG: .sig file not available
Re: Enhacement request - 'date' util
Matthew Woehlke escribió: Please use newlines and don't use HTML entities in text mail (or don't send HTML, if that was the problem). Your original mail looked like this: Good morning from Spain,first of all, thanks for your effort and for this rich featured tools... awesome work!Secondly, to the quot;datequot; command developers, it would be possible to develop the quot;-aquot; feature, like It is extremely difficult to read this block of text that has no newlines except where line wrapping occurred, is missing spaces between paragraphs, and is strewn with HTML entities. I have reformatted the relevant parts so that it is legible. Alejandro Redondo wrote: Secondly, to the date command developers, it would be possible to develop the -a feature, like other UNIXes distros do? Man from solaris 10: -a [-]sss.fff Slowly adjust the time by sss.fff seconds (fff represents fractions of a second). This adjustment can be positive or negative. The system's clock is sped up or slowed down until it has drifted by the number of seconds specified. Man from hpux 11.23: [snipped; same as above] Really useful feature to avoid crashes and dumps in apps like SAP or Oracle when changing time is needed. While that does indeed sound like an interesting option, and there is precedent of other OS's having it, I am curious why you don't just use ntpd? Hi again, sorry about those HTML characters... I sent the first email from a webmail client. And sorry about my bad English too, it's not my natal language. Well, the first clock set, when ntpd starts, is made in just one step. This can be a problem when the client host is several seconds different than the ntp server. In the example I suffered, I had to sync different flavors clients with the ntpd servers. Unluckily some of them had the ntpd daemon stopped for a lot of time and they had differences, to have an example, about 100secs (ntpdate -d ntp_serve used to know it). It was not a problem on solaris/hpux boxes to use the date -a 100.00 and then restart the ntpd daemon with the right config avoiding a 100secs jump in time. This was not the same for the Linux ones as I did not find a solution to slowly (but without notorious jumps) adjust the system clock and then restart the ntpd. Best regards,
