I have "put hard disks to sleep when possible" set in my Energy Saver preferences. My external FireWire drive does indeed sleep, but it spuriously spins up ever few minutes for no discernible reason. I did not launch any application or system service that would access the drive. Why is it spinning up?
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Why do my disks spin up?
- Thread starter bigwig
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I was not using Finder on a directory on that drive nor saving any files to that drive.
It doesn't matter if you're trying to access that drive or not. When you open a Finder window, or search or try to open or save a file through the open/save dialog box, all mounted drives will spin up so they're available to the operation, whether you select them or not. Finder doesn't know which drive you plan to use, so it makes them all ready. If you don't want it to spin up in these cases, unmount the drive.
How can the driver "take care of that"? The driver doesn't know which drive you're going to select, any more than Finder can.
The driver knows whether the disk it is attached to is being selected, because an I/O request to that drive has been initiated. There is no need to know in advance whether a drive will be selected, nor is there any need to spin up drives in anticipation of being selected. Drivers should keep drives spun down until they are actually selected, then spin them up.
This has been happening since 10.4 if not earlier. It's annoying but you do get used to it. Some external drives work better than others. I've found the delay is slightly longer when using USB external drives.
I can be somewhat annoying but you'll get used to it.
I agree. You can be somewhat annoying, but I'm used to it by now.