Secure remote execution

[tucansam]

*really* stupid newbie question.

 

I have a cable for an old APC UPS coming, should allow my unraid server to talk to the UPS for proper powerdowns upon power loss.

 

Would like to have unraid tell a bunch of other (bsd and linux) machines to begin powering down as well, as they are all connected to UPSs which lack a USB or serial port.

 

How can I securely execute remote commands?  I don't want to use rexec (passwords in the clear) and ssh of course wants a password.  I need a way to automate.

 

Comments welcome.

[JonathanM]

APCUPSD. AFAIK unRaid's APCUPSD implementation enables broadcasting by default, so as long as you can install APCUPSD on the client machines, you can tell them to shut down before the unraid machine shuts down and quits broadcasting.

 

I personally set my unraid to shut down after 5 minutes of no power, and all the slave machines are set to shut down at 3 minutes of no power. In my region, if the power is out for more than 20 seconds or so, it's going to be down for more than an hour.

 

Make sure ALL communication gear stays powered until well after all the machines are down. It doesn't take much power to keep your switches, modem and access points up, so a separate small UPS is probably a good idea.

[tucansam]

Same here.  Super reliable power, monsoon season not withstanding.  We either get super brief "blinks" where we usually don't even have to reset the clocks, or hours long (bird flew into a transformer last year, DUI wrapped his car around a power pole, etc)

 

I didn't know the software could do that -- thanks.  It looks like pfsense has a nice GUI component, might use that as my notification host, as it will be the least device to power down.

[JonathanM]

It looks like pfsense has a nice GUI component, might use that as my notification host, as it will be the least device to power down.

Obviously that means your pfsense box will be the machine physically connected to a UPS for communication. Sounds like a good plan, especially if your main switch, modem and access points are all on that UPS with the pfsense box.