Linux Foundation Certified System Administrator Practice Mode

Community Discussion

Written by other learners. Comments can disagree with the marked answer — check the official documentation when in doubt.

• Chose BD1

  Option B. Additional rules for udev can be created by adding them to /etc/udev/rules.d/ and Option D. The /dev/ directory is a filesystem of type tmpfs and is mounted by udev during system startup. Option A: When using udev, entries for devices are not created in /dev/ unless the devices are present and recognized by the system. udev dynamically creates and removes device nodes in /dev/ as devices are added and removed from the system. Option B: udev uses rules to determine how device nodes in /dev/ should be named and how they should be created and managed. Additional rules can be added to the system by creating files in the /etc/udev/rules.d/ directory.

• 1

  Option C: When using udev, it is not possible to use the mknod command to create block or character devices in /dev/. Instead, device nodes are created and managed by udev according to the rules it follows. Option D: The /dev/ directory is typically a special filesystem called tmpfs, which is mounted by udev at system startup. tmpfs is a virtual filesystem that stores its contents in volatile memory and does not use a backing store on disk. This allows udev to create and remove device nodes in /dev/ dynamically as devices are added and removed from the system. Option E: The content of /dev/ is not stored in /etc/udev/dev and is not restored during system startup. Instead, the device nodes in /dev/ are dynamically created and removed by udev according to the rules it follows.

• Chose BD1

  B, D are correct. The /dev filesystem is a temporary filesystem created by udev process to reflect the set of devices detected by the system. Additional devices not detected or not existing can be manually created by defining udev rules