Hello,
I need to shutdown a Qnap NAS when the UPS battery attached (via usb) to a mac server is low. Is it possible to automate this thing? I suppose the mac should send a command via ssh but I have no idea of how to do this automatically when the battery is at a certain percentage.
Thank you
You could try a
/usr/bin/pmset -g batt
and parse the output looking for the battery charge, then decide on whether or not you should ssh to your Qnap (I assume you have ssh-keygen keys setups so you will not be prompted for a password).
You could write a script, and run the script from a cron job on whatever periodic schedule you like.
This should already be built into the Qnap.
The NAS is more important in this case.
Now I'm gonna try to enable the NUT function on the mac, I found a tutorial on Youtube to installa software called "Fink". This method should take advantage of the NAS capability to notify the power failure to other hosts and makes the mac capable of listening to this.
https://www.youtube.com/watch?v=8rWlouT18pw&list=WL&index=29&t=0s
> The NAS is more important in this case.
Fink aside, I think the Mac is more important.
If the Mac knows the UPS is low (which is easy because it has built-in UPS monitoring), then the Mac can unmount the NAS volume and shut down gracefully. Assuming there are no other users on the NAS, you should be good to go (yes, big assumption, I know). Even if the NAS subsequently loses power, if there are no active users/files, you should be OK.
Contrast that with the NAS shutting down because the UPS is low - the Mac doesn't know this and may have open files - it could be actively saving files when the shutdown is triggered, and now you risk data loss.
So if you can't get them hooked together, focus on the Mac first.
You said you have a Mac server and a NAS. A NAS is a server too. How is it connected to the Mac? If the NAS has some kind of direct connection to the Mac, then 1) it isn’t a NAS anymore, and 2) you shouldn’t shut it down via the UPS. In this case, you would connect the UPS to the Mac instead.
They are not connected to each other, they are simply in the same network but with two different functions: the NAS is for storage while the Mac mini runs some specific software. However they share the same UPS and this UPS can be connected via USB only to one of the two.
I have very little knowledge of the subject, sorry, I have no Idea of what an ssh-Keygen is. Maybe it's getting too complicated for me.
Yes, it's a possibility but in that case I would need a way to shutdown the mac. Do you think it is possible?
Yes it is, but if I connect the ups to the QNAP via usb, I need a way to shutdown the mac
Which one will be the biggest risk for data corruption and recovery when it loses power abruptly?
The NAS would need to have a USB interface where it could talk to the UPS. That's the only way this would work.
Run an ssh command on a certain battery percentage
