Look up a volume by UUID

I know the UUID of a volume - as found in Disk Utility.

How can I get additional information on the volume? Most importantly, I want to know its mount point.

Looking at /etc/fstab doesn't do the trick. This does not 开发者_Go百科list the root volume. I would at least need to figure out the UUID of the root volume to verify my known UUID against it.

You can use diskutil to look up the disk by its UUID, and the -plist option to get the output in a machine-parseable format:

% diskutil info /Volumes/RAM\ Disk | grep -F UUID
   Volume UUID:              EA20BE94-5F3C-3C02-901D-A213B5AB6831

% diskutil info -plist EA20BE94-5F3C-3C02-901D-A213B5AB6831
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <!--snip-->
    <key>MountPoint</key>
    <string>/Volumes/RAM Disk</string>
    <!--snip-->
</dict>
</plist>

You can use NSTask and NSPipe to run diskutil from within your program and capture the output.

Addendum: Not all volumes have UUIDs. My camera has a built-in read-only MS-DOS-formatted volume that has no UUID according to Disk Utility and diskutil. So, make sure your program can handle empty output from the above diskutil info … | grep pipeline.

There are a couple of ways you can do it. If you want a list of all the UUIDs in your system you can typically look at /dev/disk/by-uuid/ .

This folder contains a symbolic link mapping uuids to device locations. On my system it maps as the following:

[sean@vladimir ~]$ ls -al /dev/disk/by-uuid/
total 0
drwxr-xr-x 2 root root 300 2010-02-02 22:42 .
drwxr-xr-x 6 root root 120 2010-02-02 22:42 ..
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 02123883-6538-4c74-bc74-362eb2588d2b -> ../../sdc4
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 1ce37cd8-52b0-4442-98b5-3702194644f2 -> ../../dm-5
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 1d718419-8175-446c-a01b-51e895d59467 -> ../../sdc7
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 382a64d7-68fe-45a3-87d3-ae7b7a861067 -> ../../dm-1
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 47ab8e51-4023-4bec-a888-576879fba2dd -> ../../sdc1
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 5b4e6b94-f7c7-40c1-a4ee-ca555efc97df -> ../../dm-4
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 6d1df3de-b408-4942-a2e3-78244a68cece -> ../../dm-0
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 c7f841db-8b38-403e-9bcc-926c18deadfc -> ../../sdc6
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 db3f2c47-e29d-4b33-a462-6230ed2bcea8 -> ../../dm-2
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 e5bd9df3-65f7-4815-839f-8b5fad82bc50 -> ../../sdc5
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 ea28833b-fa7b-465d-992b-c333b288233b -> ../../sda1
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 ebb72c56-8776-4e7d-ace9-fc727239f999 -> ../../sda2
lrwxrwxrwx 1 root root  10 2010-02-02 22:42 fd75f53b-6058-467b-9e0f-0a725e7bc83e -> ../../dm-3

Alternatively, you can run 'blkid /path/to/dev ' for each of your devices to find which is the one you are looking for. Likewise, on my system it appears as such:

[sean@vladimir ~]$ blkid /dev/sda1
/dev/sda1: LABEL="restore" UUID="ea28833b-fa7b-465d-992b-c333b288233b" TYPE="ext4" 

Hope that helps.