Question 6 of 60

The following command has just been run successfully:

Cd /opt; tar xvf /dev/nst0;

What will happen if the command sequence is run again?

    Correct Answer: D

    The command uses /dev/nst0, which is a non-rewinding tape device. When a tape device is non-rewinding, it does not rewind back to the beginning after an operation. Therefore, running the tar command again would read the next file on the tape and add its content to /opt, appending rather than overwriting the existing contents.

Question 7 of 60

FILL BLANK -

What command discards unused blocks on a mounted file system in order to support SSD devices? (Specify ONLY the command without any path or parameters.)

    Correct Answer:

    The command used to discard unused blocks on a mounted file system to support SSD devices is 'fstrim'. fstrim is specifically designed for this purpose, ensuring that unused blocks are properly discarded, which is beneficial for the performance and longevity of SSDs.

Question 8 of 60

Which single command simulates a failed device within a RAID 5 array?

    Correct Answer: D

    To simulate a failed device within a RAID 5 array using the mdadm command, you can mark the device as faulty. The appropriate command for this is 'mdadm --fail /dev/md0 /dev/sdc1'. This command tells mdadm to mark the specified device (/dev/sdc1) within the specified RAID array (/dev/md0) as failed, which simulates a device failure.

Question 9 of 60

What is the minimum number of disks required in a fully redundant RAID5 array?

    Correct Answer: C

    A RAID5 array requires a minimum of three disks to be fully redundant. RAID5 uses striping with parity, storing parity information across all the disks so that data can be reconstructed in the event of a single disk failure. With three disks, RAID5 can maintain redundancy while utilizing the storage capacity effectively.

Question 10 of 60

A system has one hard disk and one CD writer which are both connected to SATA controllers. Which device represents the CD writer?

    Correct Answer: D

    In Linux, SATA CD/DVD writers are typically represented as '/dev/sr*' devices. The first such device is usually '/dev/sr0'. Therefore, the device that represents the CD writer in this system is '/dev/sr0'.