cron v anacron

[Dean DeBruin]

Newbie here, running Ubuntu 5.10.

I understand cron and crontab, but crontab only runs /etc/cron.hourly,
anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.

At what time does anacron run /etc/cron.daily?

Why doesn't anacron show up when I do ps aux | grep anacron?

[Dean DeBruin]

Dean DeBruin wrote:

> Newbie here, running Ubuntu 5.10.
>
> I understand cron and crontab, but crontab only runs /etc/cron.hourly,
> anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.
>
> At what time does anacron run /etc/cron.daily?
>
> Why doesn't anacron show up when I do ps aux | grep anacron?

Does anacron only run at startup? That would explain some things, but
then there are problems with crontab...

[Toby Newman]

On 2006-02-28, Dean DeBruin <deandb@nospam.com> wrote:

> Newbie here, running Ubuntu 5.10.
>
> I understand cron and crontab, but crontab only runs /etc/cron.hourly,
> anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.
>
> At what time does anacron run /etc/cron.daily?
>
> Why doesn't anacron show up when I do ps aux | grep anacron?

You can use cron to run things daily, weekly and monthly.

type
$ crontab -e
to edit your crontab file.

This is a separate thing to the scripts in /etc/cron.* and is more
adaptable to your personal needs, I find.

* * * * * command to be executed
- - - - -
| | | | |
| | | | +----- day of week (0 - 6) (Sunday=0)
| | | +------- month (1 - 12)
| | +--------- day of month (1 - 31)
| +----------- hour (0 - 23)
+------------- min (0 - 59)

--
-Toby, who...
Add the word afiduluminag to the subject
field to circumvent my email filters.
Ignore any mail delivery error.

[Dean DeBruin]

Toby Newman wrote:

> On 2006-02-28, Dean DeBruin <deandb@nospam.com> wrote:
>

>>Newbie here, running Ubuntu 5.10.
>>
>>I understand cron and crontab, but crontab only runs /etc/cron.hourly,
>>anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.
>>
>>At what time does anacron run /etc/cron.daily?
>>
>>Why doesn't anacron show up when I do ps aux | grep anacron?

>
>
> You can use cron to run things daily, weekly and monthly.
>
> type
> $ crontab -e
> to edit your crontab file.
>
> This is a separate thing to the scripts in /etc/cron.* and is more
> adaptable to your personal needs, I find.
>
> * * * * * command to be executed
> - - - - -
> | | | | |
> | | | | +----- day of week (0 - 6) (Sunday=0)
> | | | +------- month (1 - 12)
> | | +--------- day of month (1 - 31)
> | +----------- hour (0 - 23)
> +------------- min (0 - 59)
>

Thank you, I'll look into that.

I was trying to run a system-wide daily backup script. I put a link to
it in /etc/cron.daily but it didn't run so I tried to figure out
/etc/crontab.

My /etc/crontab has the following lines:

> 17 * * * * root run-parts --report /etc/cron.hourly
> 25 6 * * * root test -x /usr/sbin/anacron || run-parts --report /etc/cron.daily
> 47 6 * * 7 root test -x /usr/sbin/anacron || run-parts --report /etc/cron.weekly
> 52 6 1 * * root test -x /usr/sbin/anacron || run-parts --report /etc/cron.monthly

As far as I can figure out (by reading man pages and by testing)
run-parts runs hourly, but for the daily, weekly, and monthly lines it
will only run if /usr/sbin/anacron does NOT exist! Am I missing something?

/usr/sbin/anacron DOES exist so I removed "test -x /usr/sbin/anacron ||"
from the daily, weekly, and monthly lines and now it seems to work.

[Toby Newman]

On 2006-02-28, Dean DeBruin <deandb@nospam.com> wrote:

> Toby Newman wrote:

>> On 2006-02-28, Dean DeBruin <deandb@nospam.com> wrote:
>>

>>>Newbie here, running Ubuntu 5.10.
>>>
>>>I understand cron and crontab, but crontab only runs /etc/cron.hourly,
>>>anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.
>>>
>>>At what time does anacron run /etc/cron.daily?
>>>
>>>Why doesn't anacron show up when I do ps aux | grep anacron?

>>
>>
>> You can use cron to run things daily, weekly and monthly.
>>
>> type
>> $ crontab -e
>> to edit your crontab file.
>>
>> This is a separate thing to the scripts in /etc/cron.* and is more
>> adaptable to your personal needs, I find.
>>
>> * * * * * command to be executed
>> - - - - -
>> | | | | |
>> | | | | +----- day of week (0 - 6) (Sunday=0)
>> | | | +------- month (1 - 12)
>> | | +--------- day of month (1 - 31)
>> | +----------- hour (0 - 23)
>> +------------- min (0 - 59)
>>

>
> Thank you, I'll look into that.
>
> I was trying to run a system-wide daily backup script. I put a link to
> it in /etc/cron.daily but it didn't run so I tried to figure out
> /etc/crontab.
>

Another way would be to type
$ crontab -e
to edit your user's crontab and add the following in order to run a
script at 4am each day:

shell=/bin/sh
MAILTO=yourEmailAddress@invalid.com.invalid
0 4 * * * /path/to/script --AnySwitches

--
-Toby, who...
Add the word afiduluminag to the subject
field to circumvent my email filters.
Ignore any mail delivery error.

[SINNER]

* Toby Newman wrote in alt.os.linux.ubuntu:

> Another way would be to type
> $ crontab -e
> to edit your user's crontab and add the following in order to run a
> script at 4am each day:
>
> shell=/bin/sh
> MAILTO=yourEmailAddress@invalid.com.invalid
> 0 4 * * * /path/to/script --AnySwitches

Wont that only run it on Sunday's @ 4?

--
David

[SINNER]

* Toby Newman wrote in alt.os.linux.ubuntu:

> Another way would be to type
> $ crontab -e
> to edit your user's crontab and add the following in order to run a
> script at 4am each day:
>
> shell=/bin/sh
> MAILTO=yourEmailAddress@invalid.com.invalid
> 0 4 * * * /path/to/script --AnySwitches

never mind...DOH!

--
David

[Torsten Flammiger]

Dean DeBruin schrieb:

> Toby Newman wrote:

[...]

> My /etc/crontab has the following lines:
>

>> 17 * * * * root run-parts --report /etc/cron.hourly
>> 25 6 * * * root test -x /usr/sbin/anacron || run-parts --report
>> /etc/cron.daily
>> 47 6 * * 7 root test -x /usr/sbin/anacron || run-parts --report
>> /etc/cron.weekly
>> 52 6 1 * * root test -x /usr/sbin/anacron || run-parts --report
>> /etc/cron.monthly

>
>
> As far as I can figure out (by reading man pages and by testing)
> run-parts runs hourly, but for the daily, weekly, and monthly lines it
> will only run if /usr/sbin/anacron does NOT exist! Am I missing something?
>
> /usr/sbin/anacron DOES exist so I removed "test -x /usr/sbin/anacron ||"
> from the daily, weekly, and monthly lines and now it seems to work.

-x means:
check for the existence AND check wether it is executable

so, if /usr/sbin/anacron exists and is executable it will be executed
otherwise run-parts --report will be executed.

Torsten

[Florian Diesch]

Dean DeBruin <deandb@nospam.com> wrote:

> Newbie here, running Ubuntu 5.10.
>
> I understand cron and crontab, but crontab only runs /etc/cron.hourly,
> anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.

anacron "cannot currently be used to schedule commands at intervals smaller
than days" as the README.gz says

> At what time does anacron run /etc/cron.daily?
>
> Why doesn't anacron show up when I do ps aux | grep anacron?

anacron runs at startup and is executed each morning by cron (see
/etc/crontab). It's not a daemon so it doesn't show up in ps after it
has finished today's work.


Florian
--
Das ist ja das positive am usenet: man erfährt oft Dinge, nach denen
gar nicht gefragt wurde.
[Konrad Wilhelm in <lsght1hho14bbe7in8q9currhtc7vuqfru@4ax.com>]

[Dean DeBruin]

Torsten Flammiger wrote:

> Dean DeBruin schrieb:
>

>>Toby Newman wrote:

>
>
> [...]
>
>

>>My /etc/crontab has the following lines:
>>
>>

>>>17 * * * * root run-parts --report /etc/cron.hourly
>>>25 6 * * * root test -x /usr/sbin/anacron || run-parts --report
>>>/etc/cron.daily
>>>47 6 * * 7 root test -x /usr/sbin/anacron || run-parts --report
>>>/etc/cron.weekly
>>>52 6 1 * * root test -x /usr/sbin/anacron || run-parts --report
>>>/etc/cron.monthly

>>
>>
>>As far as I can figure out (by reading man pages and by testing)
>>run-parts runs hourly, but for the daily, weekly, and monthly lines it
>>will only run if /usr/sbin/anacron does NOT exist! Am I missing something?
>>
>>/usr/sbin/anacron DOES exist so I removed "test -x /usr/sbin/anacron ||"
>>from the daily, weekly, and monthly lines and now it seems to work.

>
>
> -x means:
> check for the existence AND check wether it is executable
>
> so, if /usr/sbin/anacron exists and is executable it will be executed
> otherwise run-parts --report will be executed.
>
> Torsten

As far as I can tell, "test -x file"only checks the existence of the
file and whether it is executable. It does not execute the file. The
following experiment seems to support that idea.

dean@ubuntu:~$ ls -l ./hello
-rwxr-xr-x 1 dean dean 31 2006-02-28 23:10 ./hello
dean@ubuntu:~$ ./hello
hello, world
dean@ubuntu:~$ test -x ./hello
dean@ubuntu:~$ test -x ./hello || echo goodbye
dean@ubuntu:~$

The above experiment also shows that cron would not execute the daily,
weekly, and monthly lines in /etc/crontab.

[Dean DeBruin]

Florian Diesch wrote:

> Dean DeBruin <deandb@nospam.com> wrote:
>

>>Newbie here, running Ubuntu 5.10.
>>
>>I understand cron and crontab, but crontab only runs /etc/cron.hourly,
>>anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.

>
>
> anacron "cannot currently be used to schedule commands at intervals smaller
> than days" as the README.gz says
>
>

>>At what time does anacron run /etc/cron.daily?
>>
>>Why doesn't anacron show up when I do ps aux | grep anacron?

>
>
> anacron runs at startup and is executed each morning by cron (see
> /etc/crontab). It's not a daemon so it doesn't show up in ps after it
> has finished today's work.

Yes, I finally figured out that anacron runs at startup and then exits.
It is not a daemon. However, it is not executed each morning by cron,
nor should it be.

Anacron is intended to run at startup to catch those jobs missed by cron
while the computer is shut down. If cron is running, there is no need
for it to run anacron. I contend that the "test -x /usr/sbin/anacron
||" does not belong in /etc/crontab.

Dean

[Torsten Flammiger]

Dean DeBruin schrieb:

> Torsten Flammiger wrote:
>

>> Dean DeBruin schrieb:
>>

>>> Toby Newman wrote:

>>
>>
>>
>> [...]
>>
>>

>>> My /etc/crontab has the following lines:
>>>
>>>
>>>> 17 * * * * root run-parts --report /etc/cron.hourly
>>>> 25 6 * * * root test -x /usr/sbin/anacron || run-parts --report
>>>> /etc/cron.daily
>>>> 47 6 * * 7 root test -x /usr/sbin/anacron || run-parts --report
>>>> /etc/cron.weekly
>>>> 52 6 1 * * root test -x /usr/sbin/anacron || run-parts --report
>>>> /etc/cron.monthly
>>>
>>>
>>>
>>> As far as I can figure out (by reading man pages and by testing)
>>> run-parts runs hourly, but for the daily, weekly, and monthly lines it
>>> will only run if /usr/sbin/anacron does NOT exist! Am I missing
>>> something?
>>>
>>> /usr/sbin/anacron DOES exist so I removed "test -x /usr/sbin/anacron ||"
>>> from the daily, weekly, and monthly lines and now it seems to work.

>>
>>
>>
>> -x means:
>> check for the existence AND check wether it is executable
>>
>> so, if /usr/sbin/anacron exists and is executable it will be executed
>> otherwise run-parts --report will be executed.
>>
>> Torsten

>
>
> As far as I can tell, "test -x file"only checks the existence of the
> file and whether it is executable. It does not execute the file. The

you are right - my mistake.. beat me :-)

[Dean DeBruin]

Dean DeBruin wrote:

> Newbie here, running Ubuntu 5.10.
>
> I understand cron and crontab, but crontab only runs /etc/cron.hourly,
> anacrontab runs /etc/cron.daily, /etc/cron.weekly, and /etc/cron.monthly.
>
> At what time does anacron run /etc/cron.daily?
>
> Why doesn't anacron show up when I do ps aux | grep anacron?

For anyone following this thread, cron and anacron are working properly.
See the bug report: [url]https://launchpad.net/malone/bugs/35617[/url]