How to remount USB Flash Drive or SD card

disk-utilityhard drivesd cardusb

I noticed that I could remount my USB hard drive through terminal after I eject it by typing diskutil list to find the drive and diskutil mountDisk /dev/disk"X"…

So I tried to do the same with my SD card and my USB flash drive but…after I eject them, I cannot find them anymore through diskutil list.

I suspect this is because they are not "drive" until the system determines them as drives…which happens automatically when you plug them in – and the system remove those drives from the USB interfaces/SD card interfaces after I eject them.

So, the question is, how do I manually determine these USB interfaces/SD interfaces as "drives" so I can remount them. Thanks.

Best Answer

There's a difference between unmounting and ejecting. I'm not familiar with the CLI of diskutil, so I'll explain it using Disk Utility.app

When you have a mounted SD card you can unmount it by clicking the Unmount button in the Toolbar: enter image description here
The SD card stays in the list, but it is faded out. Then if you want to remount it again, just select the SD card and click Mount:

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Ejecting USB drive via AppleScript does not make drive power down

For starters, the greyed-out appearance in Disk Utility means the disk is unmounted, not ejected. An ejected disk does not appear at all.

The reason it shows up is that when the Cinema Display wakes, the computer sees the drive show up just as if you'd plugged it in. (Honestly, I'm surprised it doesn't mount all the way and show up on the Desktop.)

One thing that can help (particularly in the case of your second script) is to use the internal disk identifier instead of the disk name. You can find the identifier by going into Disk Utility, selecting the disk (or partition) in question, and pressing the Info button (or hit ⌘+I). In that window, look at the label next to "Disk Identifier:". A disk (whole hard drive) would look like "disk0" or "disk2", a partition looks like "disk0s0", "disk0s2", or "disk2s1". Instead of using diskutil eject DriveName, use diskutil eject /dev/disk2s0.

USB flash drive not shown

When "System Report" aka "System Profiler" does not list your USB devices, and Windows running from Boot Camp also does not list your USB devices and no power is supplied by your USB devices it is very likely that this is not a software issue.

Another way to see your connected USB devices with detailed information is to run

system_profiler SPUSBDataType

If the above fails and gives no satisfied output, it is very, very likely some of your internal hardware components are broken or disconnected.

When there are no problems with your other IO devices (e.g. firewire) it might be an internal cable that came lose, else I would suggest your south bridge is broken.

If you still think the power is the problem, try to use a powered-USB hub that will provide the juice needed for your peripherals. Or you can try to plug-in a low power consuming device like a USB mouse.

Best Answer

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Ejecting USB drive via AppleScript does not make drive power down

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