Hi can any one please help me out,How alarm feature can be tested using RTC in linux
I have tittle confusions i tried in the sysfs entry of RTC
/sys/class/rtc/rtc0/wakealarm through wakealarm i verified is that correct
echo +10 > /sys/class/rtc/rtc0/wakealarm
pm suspend
Related
My MacBook spontaneously wakes up from sleep mode with high fan activity.
I want to do a investigate this in RTC or power settings? Or by strace-ing of processes, etc (using some process/kernel magic!).
Hint: It is probably managed by "rtcwake".
I am not even sure if this is a scheduled task, or from a WiFi wakeup, or something else.
I don't want guesses about what usually causes this in Mojave, etc. Instead:
I need to do a systematic investigation on this on my MacOS (Mojave). Linux-related answers are also appreciated.
This is about system standby, sleep-mode, suspended mode. (Note that this is not about standup and wakeup of individual processes. The whole laptop turns on spontaneously.)
Reading the log file is the best way to debug the problem.
So, try this command in your Terminal to fetch the system logs,
this will tell you "wake up" history.
log show --style syslog | fgrep "Wake reason: EC.LidOpen"
To see the wake reason:
For macOS Sierra, Mojave, Catalina, and newer
log show |grep -i "Wake reason"
Or for MacOS El Capitan, Yosemite, Mavericks, and older
syslog |grep -i "Wake reason"
This will look like:
MacBookPro kernel[0] : Wake reason = OHC1
MacBookPro kernel[0] : Wake reason = PWRB
MacBookPro kernel[0] : Wake reason = EHC2
MacBookPro kernel[0] : Wake reason = OHC1
So what do these wake reason codes mean?
OHC: stands for Open Host Controller, is usually USB or Firewire. If you see OHC1 or OHC2 it is almost certainly an external USB keyboard or mouse that has woken up the machine.
EHC: standing for Enhanced Host Controller, is another USB interface, but can also be wireless devices and bluetooth since they are also on the USB bus of a Mac.
USB: a USB device woke the machine up
LID0: this is literally the lid of your MacBook or MacBook Pro when you open the lid the machine wakes up from sleep.
PWRB: PWRB stands for Power Button, which is the physical power button on your Mac
RTC: Real Time Clock Alarm, is generally from wake-on-demand services like when you schedule sleep and wake on a Mac via the Energy Saver control panel. It can also be from launchd setting, user applications, backups, and other scheduled events.
There may be some other codes (like PCI, GEGE, etc) but the above are the ones that most people will encounter in the system logs. Once you find out these codes, you can really narrow down what is causing your Mac to wake up from sleep seemingly at random.
Hope this will help :)
This answer is based on Linux, so it might not apply strictly to Mac.
To determine whether rtcwake is responsible for your MacOS wakeups, you could replace the executable (in my Ubutnu it is /usr/sbin/rtcwake) with a wrapper script that leaves a sign of rtcwake having run, e.g.
$ cd /usr/sbin/rtcwake
$ sudo mv rtcwake rtcwake_orig
and then write script /usr/sbin/rtcwake containing
#!/bin/bash
touch $HOME/rtcwake_ran
/usr/sbin/rtcwake_orig
Variants of the script would depend on your shell.
In particular, in the last line you would possibly run rtcwake in some alternative way, so as to not own the process (nohup / disown).
See https://unix.stackexchange.com/questions/152310/how-to-correctly-start-an-application-from-a-shell
To inspect possible causes of wakeup, you can check various relevant logs, at /var/log.
E.g., syslog*, acpi*.
See also https://unix.stackexchange.com/questions/83036/where-is-the-log-for-acpi-events
Do you have wakeonlan?
Here I am documenting my systematic approach. It is loosely based on, and initiated by, the answer by #vijay-rajpurohit, which is in turn based on comment by #Robert #1431720 . Note that the final result is particular to my MacOS machine, based on the logs shown below. It will be different in your MacOS.
In first attempt, I first checked the logs using: log show --style syslog | grep ... but it is taking too long. I accidentally checked /var/log/wifi.log after exploring the /var/log/ (I am also curious about /var/log/powermanagement/*.asl).
This turned out to be most useful:
cat /var/log/wifi.log|grep -i "Wake reason"
Then found this line: (note the EC. bit)
Thu Apr 23 22:41:32.359 Info: <airportd[219]> _systemWokenByWiFi: System wake reason: <EC.ARPT>, was woken by WiFi
Then googled for EC.ARPT, I found the following commands:
pmset -g log Useful stats about "Total Sleep/Wakes since boot".
pmset -g assertions This turned out to show the full answer to this question:
2020-04-24 02:23:38 +0100
Assertion status system-wide:
BackgroundTask 1
ApplePushServiceTask 0
UserIsActive 1
PreventUserIdleDisplaySleep 0
PreventSystemSleep 0
ExternalMedia 0
PreventUserIdleSystemSleep 0
NetworkClientActive 0
Listed by owning process:
pid 111(hidd): [0x0000200a000986a9] 00:00:00 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4295010950.3"
pid 85(apsd): [0x0003b830000b90bd] 00:00:10 ApplePushServiceTask named: "com.apple.apsd-waitingformessages-push.apple.com"
Kernel Assertions: 0x100=MAGICWAKE
id=504 level=255 0x100=MAGICWAKE mod=24/04/2020, 01:57 description=en0 owner=en0
Idle sleep preventers: IODisplayWrangler
In short, in a systematic approach, I explored the following keywords based on the logs, and googled each :
EC.ARPT (example link)
iohideventsystem (example link)
MAGICWAKE (example link)
ApplePushServiceTask (see below)
Most informative item emerged from the output of pmset -g assertions. For example ApplePushServiceTask in the following line:
pid 85(apsd): [0x0003b830000b90bd] 00:00:10 ApplePushServiceTask named: "com.apple.apsd-waitingformessages-push.apple.com"
The solution that seems to work in my particular case (not a general solution) was to disable :
/System/Library/LaunchDaemons/com.apple.apsd.plist using launchctl. But this cannot be done until you do a csrutil disable in the safe mode. I don't write instructions here because it need caution and you need to enable it later.
(to be updated)
My project takes pictures and I'm looking to set the image file names as the time and date they were taken.
I've programmed the camera and set up the real time clock and they both work. However, I'm now struggling to link the two.
Is there a method of returning the system time as as string?
Or anything else I may not have considered?
I used this guide for the RTC : https://www.codeproject.com/Articles/1113626/Adding-the-Missing-Real-Time-Clock-to-Windows-IoT
If you get RTC work like this guide state:
getting Windows IoT to initialize its clock from RTC at bootup so that
other solutions don't need to be modified to read from the RTC
directly.
You can use the following code line to get system time as a string:
DateTime.Now.ToString()
I am using a imx6 SabreSD. I need to set the RTC as the wake up source, and I need to set a specific time on all the day,say 12 midnight(may not be in power down mode at that time)
I have a sample
echo +x > /sys/class/rtc/rtc0/wakealarm; RTC will wake up system after x seconds
using this i can wake up system after x seconds. But i need this as 00:00:01 as time
I go to suspend state by
echo standby > /sys/power/state
Is there any way. Please help
Thanks in advance
Wake up at midnight:
date +%s -d'day 0' >/sys/class/rtc/rtc0/wakealarm
Wake up at 00:00:01:
date +%s -d'day 00:00:01' >/sys/class/rtc/rtc0/wakealarm
I'd like to use a linux pc purely to collect rss feeds, but would like to minimise it's power usage as much as possible.
Presumably I would create some kind of cron job to bring it in and out of sleep mode or are there better ways of tackling this?
Set wake up alarm in RTC, then put the computer in standby or suspend(-to-RAM) mode. Some motherboards support waking up from hibernation (suspend-to-disk), but I guess that'll be too slow.
echo `date '+%s' -d '+ 5 minutes'` > /sys/class/rtc/rtc0/wakealarm
echo -n "mem" > /sys/power/state
Replace "mem" with "standby" for stand-by instead of suspend.
BTW. MythTV's wiki has got some more in-depth info end examples.
http://www.mythtv.org/wiki/ACPI_Wakeup
How can I get a history of uptimes for my debian box? After a reboot, I dont see an option for the uptime command to print a history of uptimes. If it matters, I would like to use these uptimes for graphing a page in php to show my webservers uptime lengths between boots.
Update:
Not sure if it is based on a length of time or if last gets reset on reboot but I only get the most recent boot timestamp with the last command. last -x also does not return any further info. Sounds like a script is my best bet.
Update:
Uptimed is the information I am looking for, not sure how to grep that info in code. Managing my own script for a db sounds like the best fit for an application.
Install uptimed. It does exactly what you want.
Edit:
You can apparantly include it in a PHP page as easily as this:
<? system("/usr/local/bin/uprecords -a -B"); ?>
Examples
the last command will give you the reboot times of the system. You could take the difference between each successive reboot and that should give the uptime of the machine.
update
1800 INFORMATION answer is a better solution.
You could create a simple script which runs uptime and dumps it to a file.
uptime >> uptime.log
Then set up a cron job for it.
Try this out:
last | grep reboot
according to last manual page:
The pseudo user reboot logs in each time the system is rebooted.
Thus last reboot will show a log of all reboots since the log file
was created.
so last column of #last reboot command gives you uptime history:
#last reboot
reboot system boot **************** Sat Sep 21 03:31 - 08:27 (1+04:56)
reboot system boot **************** Wed Aug 7 07:08 - 08:27 (46+01:19)
This isn't stored between boots, but The Uptimes Project is a third-party option to track it, with software for a range of platforms.
Another tool available on Debian is uptimed which tracks uptimes between boots.
I would create a cron job to run at the required resolution (say 10 minutes) by entering the following [on one single line - I've just separated it for formatting purposes] in your crontab (cron -l to list, cron -e to edit).
0,10,20,30,40,50 * * * *
/bin/echo $(/bin/date +\%Y-\%m-\%d) $(/usr/bin/uptime)
>>/tmp/uptime.hist 2>&1
This appends the date, time and uptime to the uptime.hist file every ten minutes while the machine is running. You can then examine this file manually to figure out the information or write a script to process it as you see fit.
Whenever the uptime reduces, there's been a reboot since the previous record. When there are large gaps between lines (i.e., more than the expected ten minutes), the machine's been down during that time.
This information is not normally saved. However, you can sign up for an online service that will do this for you. You just install a client that will send your uptime to the server every 5 minutes and the site will present you with a graph of your uptimes:
http://uptimes-project.org/
i dont think this information is saved between reboots.
if shutting down properly you could run a command on shutdown that saves the uptime, that way you could read it back after booting back up.
Or you can use tuptime https://sourceforge.net/projects/tuptime/ for a total uptime time.
You can use tuptime, a simple command for report the total uptime in linux keeping it betwwen reboots.
http://sourceforge.net/projects/tuptime/
Since I haven't found an answer here that would help retroactively, maybe this will help someone.
kern.log (depending on your distribution) should log a timestamp.
It will be something like:
2019-01-28T06:25:25.459477+00:00 someserver kernel: [44114473.614361] somemessage
"44114473.614361" represents seconds since last boot, from that you can calculate the uptime without having to install anything.
Nagios can make even very beautiful diagrams about this.
Use Syslog
For anyone coming here searching for their past uptime.
The solution of #1800_Information is a good advise for the future, but I needed to find information for my past uptimes on a specific date.
Therefore I used syslog to determine when that day the system was started (first log entry of that day) and when the system was shutdown again.
Boot time
To get the system start time grep for the month and day and show only the first lines:
sudo grep "May 28" /var/log/syslog* | head
Shutdown time
To get the system shutdown time grep for the month and day and show only the last few lines:
sudo grep "May 28" /var/log/syslog* | tail