CompTIA Linux+ (XK0-006)System ManagementHard
A technician boots a rescue environment to repair a broken system installed at /mnt/sysimage. Before running 'chroot /mnt/sysimage', the technician needs the rescue environment's /dev directory to be accessible inside the chroot at the same path. Which command accomplishes this?
- Amount --bind /dev /mnt/sysimage/dev
- Bmount /dev /mnt/sysimage/dev -o remount
- Cmount -t devtmpfs /mnt/sysimage/dev
- Dln -s /dev /mnt/sysimage/dev
Show answer & explanationAnswer & explanation
Correct answer: A. mount --bind /dev /mnt/sysimage/dev
mount --bind attaches an existing directory tree (the live /dev) to another mount point so it becomes visible inside the chroot. Mounting a new devtmpfs would create empty device nodes rather than sharing the live devices, a symlink does not work reliably across chroot boundaries, and remount only reapplies options to an already-mounted filesystem.
Why the other options are wrong
- B. Remount only reapplies mount options; nothing is mounted there yet.
- C. Creates a fresh, empty device filesystem instead of sharing the live one.
- D. Symlinks do not resolve properly across a chroot jail.
mount --bind
Creates a mirror mount of an existing directory tree at another location, useful for exposing host directories (like /dev, /proc) into a chroot environment.
- Bind mount shares the same underlying data, not a copy
- Commonly used for /dev, /proc, /sys before chroot repair
- Symlinks don't work reliably across chroot boundaries
- Unmount bind mounts before exiting the rescue chroot
Memory trick: Bind = borrow the live /dev, don't build a new one