mount(8) OS X Manual Page describes the
Do not interpret character or block special devices on the file system. This option is useful for a server that has file systems containing special devices for architectures other than its own.
That alone, I don't fully understand …
… for me, the more important part of this question – which may help me to understand the option – is:
Why are USB flash drives mounted with the nodev option?
sh-3.2$ mount /dev/disk1 on / (hfs, local, journaled) devfs on /dev (devfs, local, nobrowse) /dev/disk0s2 on /Volumes/swap (hfs, local, journaled) /dev/disk0s4 on /Volumes/spare (hfs, local, journaled) map -hosts on /net (autofs, nosuid, automounted, nobrowse) map auto_home on /home (autofs, automounted, nobrowse) localhost:/Eiu9XWYlwq4E8x9l_bQTiX on /Volumes/MobileBackups (mtmfs, nosuid, read-only, nobrowse) /dev/disk3 on /Volumes/gjp22 (zfs, local, journaled, noatime) /dev/disk3s1 on /opt (zfs, local, journaled, noatime) /dev/disk6 on /Volumes/zhandy (zfs, local, journaled, noatime) /dev/disk8s1 on /Volumes/experiment (hfs, local, nodev, nosuid, journaled, noowners) /dev/disk10 on /Volumes/tall (zfs, local, journaled, noatime) /dev/disk11s2 on /Volumes/LaCie Little Big Disk (hfs, local, nodev, nosuid, journaled, noowners) /dev/disk12 on /Volumes/twoz (zfs, local, journaled, noatime) Wuala on /Volumes/WualaDrive (osxfusefs, local, nodev, nosuid, synchronous, mounted by gjp22) /dev/disk14s2 on /Volumes/Time Machine Backups (hfs, local, nodev, nosuid, journaled)
In that example, the four volumes with
- experiment – on a USB flash drive
- LaCie Little Big Disk – on a hard disk drive on FireWire 400, this volume includes a Time Machine
- Wuala – file system integration uses FUSE for OS X
- Time Machine Backups
Loosely speaking, I can understand that 2, 3, and 4 are special. However:
- I can't understand the relevance of
nodevto a USB flash drive.
Mounting USB disks automatically (How it works) – Unix and Linux
Wishing to understand why Time Machine in Lion and Mountain Lion can not back up from USB flash drives. But this question is more generally about the