This question is not related to any specific problem, only one of Mac OS curiosity arising out of watching a 6,1 Mac Pro shut down on a daily basis and how to guess or understand what's going on internally during the shut down process. Read more if interested.
Why? The 6,1 is connected by a couple of its TB2 ports to two LaCie drive arrays and one Drobo drive array, along with a LaCie 8TB external drive used as a TimeMachine and three Apple 27" displays - the old ones not made any more. After 'shutdown' is started I usually watch the T.M. LaCie's disk activity blue light using it as a monitor of the status of the shut down process, which can take up to a minute or a little more. I usually don't leave the Mac until it's completely shut down; I don't know call it one of those compulsion disorders needing completion at the end of a workday, or baseless paranoia about the shut down sequence not completing after I walk away (had that issue for some time; solved long ago).
The shutdown completes after the T.M. LaCie's blue disk activity light flickers out the last time, after blinking intermittently (no pattern) during the minute or so that the machine goes through its shut down sequence. I make sure that when I start the shutdown, it does not interrupt any backups in progress or about to start. After the shutdown procedure starts, I know it is about to complete Every Time when the LaCie T.M. blue light flickers the last time, goes out, and then the 3 displays go out all at once, the two LaCie arrays' blue lights flicker and go out and finally the Drobo's drive array lights go out and the Drobo goes into standby. All is off or in the case of the Drobo, in standby (sleeping).
The Question : what is going on during that minute of shutting down? When the LaCie T.M. light begins is strobing and flickering, it seems like it's maybe checking and recording snapshots of the other drives (the Mac's indigenous SSD, the LaCie array (two volumes) and the Drobo (two volumes)), then finally shuts down, triggering the Mac itself to complete its shut down sequence, which it always does following when the T.M.'s blue light finally goes out and that external drive shuts down. The thing is, I don't have the T.M. set to backup anything other than its default Macintosh HD boot volume, but it seems to monitor the shut down until it completes. Anybody technically OS-adroit enough to hazard a guess?
Why? The 6,1 is connected by a couple of its TB2 ports to two LaCie drive arrays and one Drobo drive array, along with a LaCie 8TB external drive used as a TimeMachine and three Apple 27" displays - the old ones not made any more. After 'shutdown' is started I usually watch the T.M. LaCie's disk activity blue light using it as a monitor of the status of the shut down process, which can take up to a minute or a little more. I usually don't leave the Mac until it's completely shut down; I don't know call it one of those compulsion disorders needing completion at the end of a workday, or baseless paranoia about the shut down sequence not completing after I walk away (had that issue for some time; solved long ago).
The shutdown completes after the T.M. LaCie's blue disk activity light flickers out the last time, after blinking intermittently (no pattern) during the minute or so that the machine goes through its shut down sequence. I make sure that when I start the shutdown, it does not interrupt any backups in progress or about to start. After the shutdown procedure starts, I know it is about to complete Every Time when the LaCie T.M. blue light flickers the last time, goes out, and then the 3 displays go out all at once, the two LaCie arrays' blue lights flicker and go out and finally the Drobo's drive array lights go out and the Drobo goes into standby. All is off or in the case of the Drobo, in standby (sleeping).
The Question : what is going on during that minute of shutting down? When the LaCie T.M. light begins is strobing and flickering, it seems like it's maybe checking and recording snapshots of the other drives (the Mac's indigenous SSD, the LaCie array (two volumes) and the Drobo (two volumes)), then finally shuts down, triggering the Mac itself to complete its shut down sequence, which it always does following when the T.M.'s blue light finally goes out and that external drive shuts down. The thing is, I don't have the T.M. set to backup anything other than its default Macintosh HD boot volume, but it seems to monitor the shut down until it completes. Anybody technically OS-adroit enough to hazard a guess?
