Yosemite is rebooting my Mac Pro multiple times per day

[Moof1904]

The title says it all. I've launched Console and looked at the entries around reboot time but I'm not seeing anything suspicious. Maybe I'm looking at the wrong logs?

Where's the best place to look? Just launch Console and look or should I open a different log from the sidebar?

What am I looking for? I've searched for "panic," "reboot," "restart," and for long strings of repeated entries.

This is maddening. It's happening as many as four or five times per day.

Update (12/14): It looks like it's probably hardware: I booted from Snow Leopard again and let the computer run for a couple of days and it rebooted spontaneously under Snow Leopard. I guess it was a coincidence that it happened around tech same time as the Yosemite upgrade. I guess I'm looking for a hardware problem now.

 

[jdphoto]

The title says it all. I've launched Console and looked at the entries around reboot time but I'm not seeing anything suspicious. Maybe I'm looking at the wrong logs?

Where's the best place to look? Just launch Console and look or should I open a different log from the sidebar?

What am I looking for? I've searched for "panic," "reboot," "restart," and for long strings of repeated entries.

This is maddening. It's happening as many as four or five times per day.

Is it a clean restart (aka does it go through he proper shutdown procedure)?

 

[NoBoMac]

Mac Pro?

I'd pop it open, make sure everything is seated properly. Blow out the dust bunnies.

Then again, can be something failing. Many moons ago at a job, had a computer that was the size of a dorm fridge. Would stay up, but every now and then, boom, crash. Eventually noticed that one particular coworker liked to come in to the lab and lean on the box. Service guy came out and found a cracked board (big pizza box sized cards in that), and the guy leaning on the box created just enough wiggle/flex on the board to "disconnect" the trace(s) at the crack.

 

[Moof1904]

I'm disinclined to believe it's a sudden hardware failure. The rebooting began occurring exactly when I upgraded to Yosemite (which did not involve a hardware change) and last week I needed to do some work in Snow Leopard, so I rebooted from an internal drive that still has SL on it and ran for two days. There was no spontaneous rebooting during that time.

JD: I've never actually seen the shutdown portion of the process. I hear the chime and run into my office and see that the system has rebooted or is still rebooting.

 

[simonsi]

Boot into safe mode, load no apps, let it run overnight, any crashes?

 

[h9826790]

Do you ever upgrade any hardware by yourself? RAM, graphic card, etc?

Did you try the normal stuff, PRAM reset, SMC reset, repair permission? (Think twice before you perform a PRAM reset if you activate TRIM for 3rd party SSD)

Did you upgrade it from Mavericks? Clean install? Or upgrade from any beta OSX?

 

[Moof1904]

I'll try the safe mode thing tonight and see if it reboots over the weekend. \

This was a clean install onto an external drive. I tested it by running from the external drive for a few days (didn't test long enough, apparently) and then cloned it to my newly wiped internal SSD using Carbon Copy Cloner.

Back to my original question: what's the best way to use the Console to glean some more information about the cause of the reboot? It may just be an incompatible app or plug-in or something that I can remove.


12/14 Update: See the edits to my original post: It looks like this is probably hardware related.