I dont make boot keys very often, an seem to have to ‘re-learn’ every time its needed. Hopefully writing it down like this will commit it to memory! So first take the USB key of choice and plug it into the Mac – I’m using a mac-mini running Mountain Lion here, but I don’t think the process has changed mush over the years.
1. Find the volume name:
MINI:~ dan$ df -h Filesystem Size Used Avail Capacity Mounted on /dev/disk0s2 297Gi 124Gi 173Gi 42% / devfs 205Ki 205Ki 0Bi 100% /dev map -hosts 0Bi 0Bi 0Bi 100% /net map auto_home 0Bi 0Bi 0Bi 100% /home /dev/disk1s2 698Gi 338Gi 360Gi 49% /Volumes/Time Machine Backups /dev/disk2s2 9.5Mi 8.7Mi 848Ki 92% /Volumes/JellyfiSSH /dev/disk3s1 7.3Gi 1.5Mi 7.3Gi 1% /Volumes/KINGSTON
Clearly the /Volumes/KINGSTON looks good for my Kingston USB key. Its the bit on the left we need (/dev/disk3s1)
2. Unmount the volume:
sudo diskutil umount /dev/disk3s1 Volume KINGSTON on disk3s1 unmounted
If you don’t unmount the disk, the next step will fail with excuses about the device being ‘busy’. Repeat step 1 to ensure the key is now unmounted:
MINI:~ dan$ df -h Filesystem Size Used Avail Capacity Mounted on /dev/disk0s2 297Gi 124Gi 173Gi 42% / devfs 205Ki 205Ki 0Bi 100% /dev map -hosts 0Bi 0Bi 0Bi 100% /net map auto_home 0Bi 0Bi 0Bi 100% /home /dev/disk1s2 698Gi 338Gi 360Gi 49% /Volumes/Time Machine Backups /dev/disk2s2 9.5Mi 8.7Mi 848Ki 92% /Volumes/JellyfiSSH
3. Write the memstick image:
The FreeBSD website shows:
dd if="FreeBSD"-8.3-RELEASE-amd64-memstick.img of=/dev/da0 bs="10240" conv="sync"
So correcting their typos and adapting for our setup here:
cd Desktop sudo dd if="FreeBSD-8.3-RELEASE-amd64-memstick.img" of=/dev/disk3 bs="10240" conv="sync"
Note that I got the of (output file) from the initial ‘df -h’. Be careful here as hosing an entire drive is more than possible if you type the wrong destination.
Depending on the system/key you are using, the process takes a few minutes.
MINI:Desktop dan$ sudo dd if="FreeBSD-8.3-RELEASE-amd64-memstick.img" of=/dev/disk3 bs="10240" conv="sync" Password: 110724+0 records in 110724+0 records out 1133813760 bytes transferred in 881.781875 secs (1285821 bytes/sec)
