[Nut-upsuser] Trying to understand sdorder

[Charles Lepple]

On Jul 8, 2017, at 4:20 AM, Roger Price wrote:
> 
> My understanding is that NUT provides a mechanism to shut down multiple systems protected by multiple UPS's in a given order.  For example to shutdown the users before their NFS server.

There are two factors at work here. 

With multiple systems, the order is enforced by waiting (up to a certain time, anyway) for the slave systems to shut down first. 

With multiple UPSes (and without the nowait flag), the shutdown commands are executed sequentially - forkexec() blocks waiting for the driver. However, the amount of time the driver spends sending the shutdown command (and possibly waiting for an acknowledgement) is driver-dependent.