I have several Firewire drives that occasionally "go missing" even though they are connected to my Mac and powered on (the power light is illuminated). These drives do not appear in Disk Utility or when I run mount
so there's no evidence of there existence that would allow me to use mount
or diskutil
to remount them. The only way I have found to re-mount them is to reboot my machine, or cycle the power the drive connected directly to my Mac (a very inconvenient process).
This issue has persisted over the course of several physical configurations (a change of Macs, rearrangement of the cabling, both FW 400 and FW 800, etc.) and is intermittent (it occurs most frequently during long periods of Mac sleep).
Why would my Firewire external drives "vanish" in this way? Is there a way to programmatically re-mount them in this case, or to prevent them from vanishing in the first place?
OS X 10.9 (issue present since 10.7, on several machine); G-Technology drives (various models); "put disks to sleep" setting is disabled; pmset
reports:
Currently in use:
standbydelay 10800
standby 1
womp 1
halfdim 1
hibernatefile /var/vm/sleepimage
darkwakes 1
networkoversleep 0
disksleep 0
sleep 1
autopoweroffdelay 14400
hibernatemode 3
autopoweroff 1
ttyskeepawake 1
displaysleep 5
acwake 0
lidwake 1
Note also that this is not a question about preventing spin-down. I've found ways to prevent this where possible, but when it's not (e.g., when the mac itself is asleep and the drives spin down because they ignore system settings to prevent spin-down), my drives frequently also unmount, thus vanishing completely from the system. The question is about how to prevent or recover from that.