I was creating an iso image from a CD ROM, and needed to unmount the drive without ejecting the disk.
cd /tmp
umount /dev/disk1s1s2
dd if=/dev/disk1s1s2 of=myCD.iso
That worked to create the iso image, however, I seemed to be unable to eject the disk even after remounting the disk. I had to reboot with the eject button held down on startup. I also made the mistake of dragging the sidebar icon of the CD to the trash, instead of the desktop icon. This has the following curious consequence: icons for OTHER CDs would show up in the finder sidebar, but not that particular one!
The solution to this problem was to open Finder preferences, and click on Sidebar. I noticed that the checkbox for "Removable Media (such as CDs" was set to a minus "-" instead of a check. Resetting this to a check fixed the problem.
cd /tmp
umount /dev/disk1s1s2
dd if=/dev/disk1s1s2 of=myCD.iso
That worked to create the iso image, however, I seemed to be unable to eject the disk even after remounting the disk. I had to reboot with the eject button held down on startup. I also made the mistake of dragging the sidebar icon of the CD to the trash, instead of the desktop icon. This has the following curious consequence: icons for OTHER CDs would show up in the finder sidebar, but not that particular one!
The solution to this problem was to open Finder preferences, and click on Sidebar. I noticed that the checkbox for "Removable Media (such as CDs" was set to a minus "-" instead of a check. Resetting this to a check fixed the problem.