What is powering up my external unmounted firewire drive?

1

I have two external hard discs connected through firewire 800 to a Macbook Pro. Usually I only work with one, so I unmount the other, which powers down. However, after some time the unmunted hard disk powers up for a while, then powers down. What is causing this activity? Can I somehow prevent it?

Grzegorz Adam Hankiewicz

Posted 2011-03-03T10:50:51.103

Reputation: 1 029

Answers

2

Preventing will be quite complicated, as not only a lot of system processes check for certain files on all hard drives regularly (think spotlight, time machine, etc.) and more often than not, opening a "choose file" dialog will spin up all hard drives, too, since the OS wants to leave you with a "fast" impression and thus spins up drives in advance.

Asmus

Posted 2011-03-03T10:50:51.103

Reputation: 2 007

I know that happens when the drive is mounted, but in this case it is unmounted. Normal software should be unable to even know something is connected. – Grzegorz Adam Hankiewicz – 2011-03-03T14:16:01.067

@Grzegorz I take it you are daisy chaining the drives? If so, is the one that is supposed to be unmounted and sleeping the first in line or the second? – Asmus – 2011-03-03T17:48:17.477

The setup is macbook pro <-> firewire 800 hd (turned on) <-> firewire 400. The firewire 800 hd has a power of switch, but the 400 one doesn't, so it randomly powers up even though its not mounted or available in finder. The 800 hd is always powered on. – Grzegorz Adam Hankiewicz – 2011-03-03T21:06:13.313