Time machine backup not running

Thank you, Kevin! 🙂 I inserted the string:

sudo defaults write /Library/Preferences/com.apple.TimeMachine RequiresACPower -bool FALSE

and I rebooted.

Tonight or tomorrow I will see if Time Machine will work well.

Still remains that at login keeps popping-up the annoying window that warns that the computer is not powered! (???...)

For those who have not read my previous post: this window appears briefly after starting, just for 1/10 second, before of the window to insert the login password.

In the Mac very fast is almost impossible to see this alarm and I suggested to record a movie with an iPhone; when you play the video, you will see if this alarm appears when the USB cable is connected to the UPS.

I think that the issue depends by the new modalities of El capitan to manage the USB ports and only Apple can fix it...

My Apple Bug report number is

23316060

Time Machine also started working correctly for me once I had disconnected my computer (iMac 27 inch, Late 2013) from its UPS system. As soon as the UPS is re-connected the hourly and daily backups from Time Machine stop.

I have also moved the external disk that TM is backing up to, on to a USB port on the rear of my Airport Extreme. Once I selected the disk for use by Time Capsule a backup was initiated - even with the UPS being re-connected.

Regards,

Cliff

netnothing wrote:

If anyone gets an Apple engineer to call.....simply send them to this Macrumors forum post:

http://forums.macrumors.com/threads/tm-auto-backups-still-broken-in-10-11-1.1931 065/#post-22162593

Pretty sure he nailed it. Seems that if Apple is still trying to figure this out, we are all in trouble.

I'm not sure what you think the MacRumors poster 'nailed.' The Terminal command does the same thing as the System Preferences > Time Machine > Options item that enables TM backups on laptops while they are running on battery power. Setting it via the Terminal on either desktop or laptop Macs, or by using the System Preference on laptops, should have no effect unless the Mac is in fact running on battery power at the scheduled backup time.

Since the issue is that the scheduled backups don't run even when the Mac clearly is running on AC power, that is not a fix -- in fact, setting the preference to allow TM backups on other than AC power could cause problems if it takes much power to complete a large backup (since that could deplete a laptop or a UPS battery before the backup completes, shutting down the Mac abruptly & leaving the backup in an unknown state).

The problem pretty clearly seems to be related to how El Capitan polls a USB connected UPS at startup time, which leads to a persistent disabling of scheduled backups until whatever is causing that is eliminated by restarting without the USB cable connected. That is what Apple has to figure out & eliminate.

Thanks Gerald. Seeing so many entries about UPS systems had me disconnect my UPS and Time Machine started immediately.

I even moved the external disk that my iMac uses for Time Machine to a USB port on the back of my Airport Extreme and Time Machine has been backing up to this for about 30 minutes at the moment. It has taken this backup as the "first" so it is a very big backup and it is very slow. I have plugged the UPS connection back in to its USB port and the backup is still in progress.

Is it possible that the Time Machine issue really down to a USB related fault do you think?

Cliff

Cliff Drew1 wrote:

Time Machine also started working correctly for me once I had disconnected my computer (iMac 27 inch, Late 2013) from its UPS system. As soon as the UPS is re-connected the hourly and daily backups from Time Machine stop.

This happens even if you don't restart the Mac after reconnecting the USB cable to the UPS?

That isn't the case for me. As long as the cable is disconnected at startup time, I can plug it back in afterwards & scheduled backups continue to occur regularly.

Open the App store, search for El Capitan.

Hi William,

Yes, I have - I logged a fault and sent them some data they asked for. As I've tried things I've sent updates. Please see bug 23292587 on bug reporter.

Cliff

I just got a call from Apple and I gave them all the info on this. They are definitely aware of the problem and know it's an issue with a UPS attached. They are working on a fix which will be in a future update.

netnothing, has anyone one proven this method yet? I have done the steps and it has done one backup with the UPS plugged in via USB. I am waiting to see if it will do anymore. Then I will restart and see if it continues to work. Again, anyone tried this Terminal string and completed the steps I am undergoing? Reason I am asking is because we have R C-R telling us it is not a fix and could be a bad thing to do with desktops?

It's not a fix....it's a workaround. It's pointing to the fact there is something in El Cap that is reading power settings incorrectly related to TM. The command is basically saying, always run TM backups, even if running on battery power. Yes that could be bad IF you were running on battery power.

Some people, including R C-R, have had luck restarting without the USB cable plugged in, and then plugging it in after the system starts. This leans more towards it being something the system is looking at during startup. But if your machine reboots with it plugged in, it will not run backups. I'd try this method.

It's clearly something in the power settings of El Cap, because I had the issue on my Macbook Air, not being plugged into a UPS via USB.

-Kevin

So then it is not a fix or a Work around. Sounds to me like a waste of time. I do not like entering anything into Terminal. Whomever came up with this brilliant idea should have explained that it does not fix the problem. It is only something to throw another step into rebooting, having to unplug and replug your UPS in. How dumb to even suggest someone to do that, when we clearly already new the problem and to leave the UPS unplugged until Apple figures it out.

No, the terminal commands (which I haven't tested) don't require the unplug and replug of the USB cable. That's the workaround for NOT doing the terminal commands.

-Kevin

net nothing: So you are saying you don't know if this terminal command works or not? Why did you write in your previous reply that: "Some people, including R C-R, have had luck restarting without the USB cable plugged in, and then plugging it in after the system starts. This leans more towards it being something the system is looking at during startup. But if your machine reboots with it plugged in, it will not run backups. I'd try this method." So in a nutshell, I should just continue my experiment with the Terminal command and see if it works?

GreekGeek1157 wrote:

Reason I am asking is because we have R C-R telling us it is not a fix and could be a bad thing to do with desktops?

To be clear about it, what I'm saying is it is not generally a good idea to start what might be a lengthy TM backup while the Mac (& presumably the TM backup drive) are running off the battery in a UPS (or in a laptop). For instance, I know that my APC UPS, which powers both my iMac & its local USB TM backup drive, is only good for around 15 minutes of backup power at most. So if a TM backup takes longer than that, the backup won't complete before both the Mac & the drive shut down.

At best, that will leave in place a 'backup in progress' partial backup on the TM drive that TM can finish later, but in my experience that sometimes doesn't happen & it gets 'stuck' trying to resume that, or forces a 'deep scan' that can take many hours to complete before the next backup can occur.