Can cron work during sleep?

Stan Randle wrote on :
Can cron perform scheduled updates while a Mac is in sleep?
Tom Stiller replied on :

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping. You might try anacron (easily available via fink) which attempts to "catch-up" on tasks whose execution is past-due.

matt neuburg replied on :

In article tomstiller-A9ED0A.17125411032002@redacted.invalid, Tom Stiller tomstiller@redacted.invalid wrote:

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping

That's the conventional wisdom, but I wonder whether it's still true. I always put the computer to sleep manually every night, but since installing 10.1.3 I've noticed that my computer is awake in the morning, and that my logs are being rotated weekly. m.

Adriaan Tijsseling replied on :

In article matt-1103021708570001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

In article tomstiller-A9ED0A.17125411032002@redacted.invalid, Tom Stiller tomstiller@redacted.invalid wrote:

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping

That's the conventional wisdom, but I wonder whether it's still true. I always put the computer to sleep manually every night, but since installing 10.1.3 I've noticed that my computer is awake in the morning, and that my logs are being rotated weekly. m.

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

Adriaan


   email:     adriaan + tijsseling . com
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Tom Harrington replied on :

In article matt-1103021708570001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

In article tomstiller-A9ED0A.17125411032002@redacted.invalid, Tom Stiller tomstiller@redacted.invalid wrote:

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping

That's the conventional wisdom, but I wonder whether it's still true. I always put the computer to sleep manually every night, but since installing 10.1.3 I've noticed that my computer is awake in the morning, and that my logs are being rotated weekly. m.

Easy enough to discover; look in /var/log/system.log for entries tagged as "CRON".

matt neuburg replied on :

In article nospam-45DF1F.10162112032002@redacted.invalid, Adriaan Tijsseling nospam@redacted.invalid wrote:

In article matt-1103021708570001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

In article tomstiller-A9ED0A.17125411032002@redacted.invalid, Tom Stiller tomstiller@redacted.invalid wrote:

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping

That's the conventional wisdom, but I wonder whether it's still true. I always put the computer to sleep manually every night, but since installing 10.1.3 I've noticed that my computer is awake in the morning, and that my logs are being rotated weekly. m.

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

Mine is not on and never has been, so that can't be the correct explanation. m.

Tom Stiller replied on :

In article matt-1103021708570001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

In article tomstiller-A9ED0A.17125411032002@redacted.invalid, Tom Stiller tomstiller@redacted.invalid wrote:

In article 1f8w2ki.8mjiiz1nrun79N%stanman2171@redacted.invalid, stanman2171@redacted.invalid (Stan Randle) wrote:

Can cron perform scheduled updates while a Mac is in sleep?

Not if the processor is sleeping

That's the conventional wisdom, but I wonder whether it's still true. I always put the computer to sleep manually every night, but since installing 10.1.3 I've noticed that my computer is awake in the morning, and that my logs are being rotated weekly. m.

My system sleeps through the night; as always, your milage may vary.

Bird replied on :

In article matt-1203020400190001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

In article nospam-45DF1F.10162112032002@redacted.invalid, Adriaan Tijsseling nospam@redacted.invalid wrote:

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

Mine is not on and never has been, so that can't be the correct explanation. m.

I tried the above option lasts night, but my computer seems to have slept through the night. The logs show no changes.

Bird

Neill Massello replied on :

Stan Randle stanman2171@redacted.invalid wrote:

Can cron perform scheduled updates while a Mac is in sleep?

A Mac can't really do anything ~while~ it is in deep sleep; it must first wake up. The only thing that can wake a sleeping Mac is the PMU (Power Management Unit), which is more than your average power switch. Here's the description of the PMU from the Apple KB article about resetting it:

"The PMU (Power Management Unit) is a microcontroller chip that controls all power functions for the computer. The PMU is a computer within a computer. It has memory, software, firmware, I/O, two crystals, and a CPU. Its functions is to:

  • Tell the computer to turn on, turn off, sleep, wake, idle, etc.
  • Manage system resets from various commands.
  • Maintain parameter RAM (PRAM).
  • Manage the real-time clock."

A Mac's PMU only wakes when it detects signals -- and I don't know how discriminating it is about parsing those signals -- on particular ports or when the clock reaches a particular time. Setting startup and shutdown times was an option in the OS 9 Energy Saver but no longer appears in the current OS X System Preferences. All processes running on the CPU are put into "suspended animation" when a Mac goes into deep sleep: the only processes active during deep sleep are those running on the PMU's processor. As a UNIX daemon that knows nothing of the Mac PMU, cron doesn't register a wake time with the PMU, and the Mac sleeps through the times appointed for the cron jobs.

In my experience, the cron jobs don't take long and don't disrupt normal work while they're running anyway, so they can be rescheduled to run at any time of day that your Mac is most likely to be on and awake. I rescheduled them to run in the late afternoon using the freeware app CronniX.

Chip Zempel replied on :

In article matt-1203020400190001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote:

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

Mine is not on and never has been, so that can't be the correct explanation. m.

According to David Pogue's "Mac OS X: The MIssing Manual" this option only applies to OS X Server.

Chip

Peter Sealy replied on :

In article matt-1203020400190001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote: snip

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

Mine is not on and never has been, so that can't be the correct explanation. m.

BWG3s do not have the Options tab in the Energy Saver for X. Don't know why, does anyone?

D A Vincent replied on :

Peter Sealy pandcsealy@redacted.invalid writes:

In article matt-1203020400190001@redacted.invalid, matt@redacted.invalid (matt neuburg) wrote: snip

If you go to the Energy saver and click the Options tab, you will notice an option "Wake for network administrative access". If that is on, cron will work if the computer is asleep. Otherwise, not.

[...]

BWG3s do not have the Options tab in the Energy Saver for X. Don't know why, does anyone?

I'll take a wild guess that the Blue & White G3 hardware does not support the features under the Options tab, such as waking for network admin access.

d.