EX200 Create and configure file systems Practice Test 4 — 15 Questions

Question 1

A partition /dev/sdc1 is formatted as ext4. The administrator needs to check the file system for errors without making any repairs. Which command should be used?

Accepted Answer

fsck -n /dev/sdc1. The `fsck -n` command checks the file system for errors without making any repairs, as the `-n` flag forces a non-interactive, read-only check. Since /dev/sdc1 is formatted as ext4, `fsck` automatically calls the appropriate ext4-specific tool (e2fsck) with the no-repair option. This matches the requirement to only check for errors without fixing them.

Answer

xfs_repair -n /dev/sdc1

Answer

fsck -y /dev/sdc1

Answer

e2fsck -p /dev/sdc1

Question 2

A server has an LVM volume group vg01 with a physical volume /dev/sdb. The administrator wants to move all physical extents from /dev/sdb to /dev/sdd which is also in the same volume group. Which command sequence is correct?

Accepted Answer

pvmove /dev/sdb; vgreduce vg01 /dev/sdb. The correct sequence is to first use `pvmove /dev/sdb` to relocate all physical extents from /dev/sdb to other physical volumes in the same volume group (vg01), and then use `vgreduce vg01 /dev/sdb` to remove the now-empty physical volume from the volume group. This ensures no data loss and that the volume group metadata is properly updated.

Answer

vgreduce vg01 /dev/sdb; pvmove

Answer

pvmove /dev/sdb; pvremove /dev/sdb

Answer

pvmove /dev/sdb /dev/sdd

Question 3

In /etc/fstab, which values in the dump and pass fields enable automatic file system checking at boot?

Accepted Answer

dump=0, pass=1. The `pass` field in `/etc/fstab` controls the order of file system checks at boot. A value of 1 means the root file system is checked first, and a value of 2 or higher means other file systems are checked after root. The `dump` field is for backup utility (dump) and is not related to boot-time checking; it must be 0 to disable dump. Thus, `dump=0, pass=1` enables automatic file system checking (fsck) at boot for the root file system.

Answer

dump=1, pass=0

Answer

dump=0, pass=0

Answer

dump=1, pass=1

Question 4

Which THREE of the following commands can be used to display information about file systems?

Accepted Answer

df. The `df` command displays information about mounted file systems, including total size, used space, available space, and mount points. It reads the /proc/mounts file to show file system usage statistics, making it a primary tool for file system information.

Answer

fdisk

Answer

du

Question 5

Which TWO of the following are valid mount options for enabling quotas on an ext4 file system?

Accepted Answer

grpquota. `grpquota` is a valid mount option for enabling group quotas on an ext4 file system. Option E is correct because `usrquota` is the valid mount option for enabling user quotas. Both options are recognized by the `mount` command and the ext4 driver to activate quota tracking at mount time.

Answer

quota

Answer

userquota

Answer

noquota

Question 6

The administrator attempts to run 'xfs_growfs /dev/vg00/lvol1' but receives an error. What is the most likely cause?

Accepted Answer

The logical volume is not mounted. The `xfs_growfs` command requires the XFS filesystem to be mounted in order to resize it. If the logical volume `/dev/vg00/lvol1` is not mounted, the kernel cannot access the filesystem's superblock and allocation group information, causing the command to fail with an error such as 'XFS filesystem not mounted' or 'No such file or directory'.

Answer

The file system is not XFS

Answer

Unmet dependencies

Answer

The volume group is full

Question 7

The administrator wants to reduce the file system size to 40GB. Which command sequence should be used?

Accepted Answer

It is not possible to shrink an XFS file system. XFS is a high-performance 64-bit journaling file system that does not support online or offline shrinking. Once an XFS file system is created, its size cannot be reduced; the only way to reclaim space is to back up the data, destroy the file system, recreate it at the desired size, and restore the data. Therefore, any attempt to shrink an XFS file system using lvreduce or similar tools will corrupt the file system.

Answer

xfs_repair; lvreduce

Answer

umount /mnt/data; lvreduce -L 40G; mount; xfs_growfs

Answer

lvreduce -L 40G /dev/vg00/lvol0; xfs_growfs

Question 8

The administrator wants to create a new ext4 file system on /dev/sdb1 with a block size of 1024 bytes. Which command should be used?

Accepted Answer

mkfs.ext4 -b 1024 /dev/sdb1. The `-b` flag in `mkfs.ext4` specifies the block size in bytes. To create an ext4 filesystem with 1024-byte blocks on /dev/sdb1, the command `mkfs.ext4 -b 1024 /dev/sdb1` is used. This is the standard syntax for setting the logical block size when formatting an ext4 filesystem.

Answer

mkfs.ext4 -B 1024 /dev/sdb1

Answer

mkfs.ext4 -s 1024 /dev/sdb1

Answer

mkfs.ext4 --block-size 1024 /dev/sdb1

Question 9

A system administrator needs to create an XFS filesystem on /dev/sdb1 with the label 'data'. Which command should be used?

Accepted Answer

mkfs.xfs -L data /dev/sdb1. The `mkfs.xfs` command creates an XFS filesystem, and the `-L` flag assigns a label to the filesystem during creation. The command `mkfs.xfs -L data /dev/sdb1` correctly creates an XFS filesystem on the specified partition with the label 'data'.

Answer

mkfs.ext4 -L data /dev/sdb1

Answer

mkfs.xfs -l data /dev/sdb1

Answer

xfs_admin -L data /dev/sdb1

Question 10

After adding a new disk /dev/sdc, a system administrator wants to mount it persistently at /mnt/backup. Which entry in /etc/fstab is most reliable?

Accepted Answer

UUID=abc123... /mnt/backup xfs defaults 0 0. Using the UUID (Universally Unique Identifier) ensures the filesystem is mounted persistently regardless of device name changes (e.g., /dev/sdc could become /dev/sdd after a reboot or disk addition). The UUID is generated when the filesystem is created and remains constant, making it the most reliable method for persistent mounts in /etc/fstab.

Answer

LABEL=data /mnt/backup xfs defaults 0 0

Answer

PARTUUID=def456... /mnt/backup xfs defaults 0 0

Answer

/dev/sdc /mnt/backup xfs defaults 0 0

Question 11

A server has an LVM volume group 'vg_data' with a logical volume 'lv_data' formatted as ext4. The administrator needs to increase the filesystem size by 2 GB without unmounting. Which set of commands should be used?

Accepted Answer

lvextend -L +2G /dev/vg_data/lv_data && resize2fs /dev/vg_data/lv_data. The filesystem is ext4, which supports online resizing. The `lvextend` command first expands the logical volume by 2 GB, and then `resize2fs` grows the ext4 filesystem to fill the newly allocated space—all without unmounting.

Answer

lvresize -L +2G /dev/vg_data/lv_data && xfs_growfs /mountpoint

Answer

lvextend -L +2G /dev/vg_data/lv_data

Answer

umount /dev/vg_data/lv_data && lvextend -L +2G /dev/vg_data/lv_data && mount /dev/vg_data/lv_data /mountpoint

Question 12

Which command displays the UUID of a filesystem on /dev/sda1?

Accepted Answer

blkid /dev/sda1. The `blkid` command is specifically designed to locate and print block device attributes, including the UUID (Universally Unique Identifier) of a filesystem. Running `blkid /dev/sda1` queries the device's superblock and outputs the UUID, filesystem type, and other metadata, making it the correct tool for this task.

Answer

df -h

Answer

mount

Answer

fdisk -l /dev/sda

Question 13

Which TWO commands are needed to set up a swap partition on /dev/sdd1 for immediate use?

Accepted Answer

swapon /dev/sdd1. The `swapon /dev/sdd1` command activates the swap partition immediately, making it available for the kernel to use as virtual memory. Option C is correct because `mkswap /dev/sdd1` writes the swap signature (UUID and swap superblock) to the partition, which is a prerequisite for any swap device to be recognized by the kernel. Together, these two commands first prepare the partition as a swap area and then enable it for immediate use.

Answer

parted /dev/sdd mkswap

Answer

swapon -a

Answer

mkfs.swap /dev/sdd1

Question 14

The root filesystem is at 90% capacity. Which command increases available space without unmounting?

Accepted Answer

lvextend -L +5G /dev/mapper/vg_root-lv_root && xfs_growfs /. It first extends the logical volume with `lvextend -L +5G`, then grows the XFS filesystem online with `xfs_growfs /` to utilize the new space without unmounting. This is the proper procedure for XFS filesystems, which require `xfs_growfs` (not `resize2fs`) to expand while mounted.

Answer

fstrim /

Answer

resize2fs /dev/mapper/vg_root-lv_root

Answer

lvextend -L +5G /dev/mapper/vg_root-lv_root

Question 15

A Red Hat Enterprise Linux 8 server is used as a file server. It has a 1 TB disk /dev/sdc formatted as XFS and mounted at /srv/files. The /etc/fstab entry uses the device name /dev/sdc. After a hardware replacement, the new disk is detected as /dev/sdd, and the server fails to boot because /srv/files cannot be mounted. The administrator used 'blkid' and found the new disk's filesystem UUID is 'abc-123'. What is the best course of action to ensure reliable mounting after future reboots?

Accepted Answer

Change the /etc/fstab entry to use UUID=abc-123 and run mount -a. Using the filesystem UUID in /etc/fstab provides a persistent identifier that remains constant regardless of the device name assigned by the kernel. After the hardware replacement, the disk is detected as /dev/sdd, but its UUID ('abc-123') is unchanged. Changing the fstab entry to UUID=abc-123 ensures the system can reliably mount the filesystem on every boot, as the UUID is tied to the filesystem itself, not the kernel's device enumeration order.

Answer

Add the 'nofail' option to the /etc/fstab entry and reboot

Answer

Create a symbolic link /dev/sdc pointing to /dev/sdd

Answer

Use PARTUUID instead of UUID in /etc/fstab