EX200 Configure local storage Practice Test 5 — 15 Questions

Question 1

Which TWO of the following are valid reasons to use LVM in a Red Hat Enterprise Linux environment?

Accepted Answer

Ability to resize logical volumes without repartitioning. Option B is correct because LVM allows you to resize logical volumes (LVs) online or offline without needing to repartition the underlying disk, which is a key advantage over traditional partitions. Option C is correct because LVM provides snapshot functionality, which creates a point-in-time copy of a logical volume for consistent backups or testing, without requiring additional backup software.

Answer

Improved disk I/O performance over direct partitions

Answer

Simplification of disk partitioning by removing the need for partitions

Answer

Ability to create RAID arrays without mdadm

Question 2

Which TWO of the following are required steps when migrating a logical volume from one physical volume to another in the same volume group?

Accepted Answer

Remove the source physical volume from the volume group with vgreduce after migration. Option C is correct because after using pvmove to relocate all physical extents from the source physical volume to the target, you must remove the source PV from the volume group using vgreduce to clean up the volume group metadata and free the device for other use. This step ensures the volume group no longer references the now-empty source PV.

Answer

Delete and recreate the logical volume on the new physical volume

Answer

Add the new physical volume to the volume group with vgextend if not already present

Answer

Extend the logical volume to include the new physical volume

Question 3

Which THREE of the following are valid utilities for creating partitions on a disk in Red Hat Enterprise Linux?

Accepted Answer

fdisk. C is correct because `fdisk` is a traditional command-line utility for creating, deleting, and managing MBR (Master Boot Record) partition tables on disks in Red Hat Enterprise Linux. It supports interactive and scripted partitioning, making it a valid tool for local storage configuration.

Answer

mkfs

Answer

mount

Question 4

An administrator wants to add 20GB of additional space to the root filesystem. The volume group vg01 has no free extents. Which action should be taken first?

Accepted Answer

Attach a new disk, create a physical volume on it, add it to vg01 with vgextend, then extend vg01-root. Option D is correct because to extend the root filesystem when the volume group has no free extents, you must first add a new physical volume to the volume group. This involves attaching a new disk, creating a physical volume on it with `pvcreate`, adding it to vg01 with `vgextend`, and then using `lvextend` followed by `resize2fs` (or `xfs_growfs` for XFS) to extend the logical volume and filesystem. This sequence ensures the volume group has available extents before extending the logical volume.

Answer

Shrink the logical volume vg01-data and then extend vg01-root

Answer

Run vgextend vg01 /dev/sdc (assuming /dev/sdc is a new disk) but this command requires the PV to be created first

Answer

Use lvextend to extend the root logical volume into the free space of sdb1

Question 5

The /data filesystem is at 99% capacity. The LVM setup shows that the volume group has 50GB free space, but the logical volume is only 100GB. What is the correct sequence of commands to increase the filesystem to use all available space in the volume group?

Accepted Answer

lvextend -L +50G /dev/mapper/vg01-data && xfs_growfs /data. Option B is correct because the volume group has 50GB free space, so you need to extend the logical volume by +50GB (not to 50GB) using `lvextend -L +50G`, and then grow the XFS filesystem with `xfs_growfs /data` (the mount point, not the block device). The `+` sign indicates an addition to the current size, while omitting it would set an absolute size.

Answer

lvextend -L 50G /dev/mapper/vg01-data && xfs_growfs /dev/mapper/vg01-data

Answer

lvextend -L +50G /dev/mapper/vg01-data && resize2fs /dev/mapper/vg01-data

Answer

xfs_growfs /dev/mapper/vg01-data && lvextend -L +50G /dev/mapper/vg01-data

Question 6

An administrator needs to mount the backup filesystem with the ‘exec’ option temporarily for a one-time script. Which command will remount the filesystem with exec without unmounting?

Accepted Answer

mount -o remount,exec /mnt/backup. Option C is correct because the `mount -o remount,exec /mnt/backup` command changes the mount options of an already-mounted filesystem without unmounting it. The `remount` option applies the specified mount options (in this case, `exec`) to the existing mount point, and the filesystem path (device or mount point) is sufficient for the kernel to identify and modify the mount. This is the standard method for altering mount options on a live filesystem in Linux.

Answer

umount /mnt/backup && mount /mnt/backup

Answer

mount -o exec,remount /dev/sdc1 /mnt/backup

Answer

mount -a -o exec

Question 7

An administrator needs to add a new 20GB disk /dev/sdb to a RHEL 9 server and mount it permanently at /data. The disk is unpartitioned. Which sequence of commands correctly accomplishes this?

Accepted Answer

fdisk /dev/sdb → mkfs.ext4 /dev/sdb1 → echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab → mount -a. Option D is correct because it follows the proper sequence for adding a new unpartitioned disk: create a partition with fdisk, format the partition with mkfs.ext4, add an entry to /etc/fstab for permanent mounting, and then use mount -a to mount all filesystems from fstab. This ensures the disk is mounted persistently across reboots, which is required by the question.

Answer

fdisk /dev/sdb → mkfs.ext4 /dev/sdb1 → mount /dev/sdb1 /data

Answer

mkfs.ext4 /dev/sdb → mount /dev/sdb /data

Answer

parted /dev/sdb → mkfs.ext4 /dev/sdb1 → mount /dev/sdb1 /data

Question 8

A volume group vg_data has no free extents. An admin adds a new disk /dev/sdc and wants to extend the logical volume lv_data (ext4 filesystem) by 5GB. Which sequence of commands is correct?

Accepted Answer

pvcreate /dev/sdc → vgextend vg_data /dev/sdc → lvextend -L+5G /dev/vg_data/lv_data → resize2fs /dev/vg_data/lv_data. Option B is correct because it follows the proper sequence: first create the physical volume with pvcreate, then extend the volume group with vgextend, then extend the logical volume with lvextend, and finally resize the ext4 filesystem with resize2fs. Since the filesystem is ext4, the resize2fs command is required after lvextend to make the additional space available to the filesystem.

Answer

pvcreate /dev/sdc → vgextend vg_data /dev/sdc → lvextend -L+5G /dev/vg_data/lv_data

Answer

lvextend -L+5G /dev/vg_data/lv_data → pvcreate /dev/sdc → vgextend vg_data /dev/sdc

Answer

fdisk /dev/sdc → mkfs.ext4 /dev/sdc1 → pvcreate /dev/sdc1 → vgextend vg_data /dev/sdc1 → lvextend -L+5G /dev/vg_data/lv_data

Question 9

A system fails to mount an XFS filesystem at boot. The /etc/fstab entry is: UUID=abc123 /mnt xfs defaults 0 0. Running mount -a shows: 'mount: wrong fs type, bad option, bad superblock on /dev/sdb1'. Which is the most likely cause?

Accepted Answer

The UUID specified in fstab does not match the actual UUID of /dev/sdb1.. The error message 'wrong fs type, bad option, bad superblock' typically indicates that the system cannot identify the filesystem on the device. Since the fstab entry uses UUID=abc123, the most likely cause is that the UUID specified does not match the actual UUID of /dev/sdb1, causing mount to attempt to mount a device that either does not exist or has a different filesystem signature. The mount command first resolves the UUID to a device, and if the UUID is incorrect, it may try to mount the wrong device or fail to find one.

Answer

The mount point /mnt does not exist.

Answer

The kernel does not have XFS support enabled.

Answer

The filesystem on /dev/sdb1 is not XFS but ext4.

Question 10

Which single command shows the UUID of a filesystem on /dev/sdb1?

Accepted Answer

blkid /dev/sdb1. The `blkid /dev/sdb1` command queries the libblkid library to read the filesystem metadata directly from the block device, displaying attributes including the UUID (Universally Unique Identifier) stored in the superblock. This is the standard, single-purpose command to retrieve the UUID of a specific partition.

Answer

df -h

Answer

mount

Answer

fdisk -l

Question 11

An administrator replaces a failed disk in a RAID 10 array /dev/md0. The new disk is /dev/sdc. The admin runs: mdadm /dev/md0 --add /dev/sdc. The command succeeds, but the array does not start rebuilding. What is the most likely reason?

Accepted Answer

The failed disk was not removed from the array first; you need to mark it as failed and remove it.. Option D is correct because when a disk in a RAID array fails, the array marks it as faulty but does not automatically remove it. The administrator must first explicitly mark the failed disk as failed with `mdadm --fail` and then remove it with `mdadm --remove` before adding a replacement. Without removing the failed device, the array still considers the old disk as part of the array, and the new disk is not recognized as a replacement, so no rebuild starts.

Answer

The new disk must be partitioned with the same layout as the failed disk.

Answer

The --add command should have been --re-add instead.

Answer

The array is still clean and does not need the new disk yet.

Question 12

Which TWO commands can be used to create a physical volume for LVM? (Choose exactly two.)

Accepted Answer

pvcreate /dev/sdb1. The `pvcreate` command initializes a block device (such as a partition or an entire disk) for use as a physical volume in LVM. Option B targets a partition `/dev/sdb1`, and option C targets the whole disk `/dev/sdb` — both are valid devices that can be initialized as physical volumes, as LVM can operate on either.

Answer

mkfs.ext4

Answer

lvcreate

Answer

vgcreate

Question 13

Which THREE filesystem types are natively supported in RHEL 8/9 for local storage? (Choose exactly three.)

Accepted Answer

vfat. A is correct because vfat (FAT32) is natively supported in RHEL 8/9 for local storage, primarily for compatibility with UEFI boot partitions and removable media. The kernel includes the vfat module, and mkfs.vfat is available from the dosfstools package, allowing creation and mounting of FAT32 filesystems without additional software.

Answer

ntfs

Answer

btrfs

Question 14

Which TWO commands can be used to list block devices and their attributes? (Choose exactly two.)

Accepted Answer

lsblk. B (lsblk) is correct because it lists all block devices (e.g., /dev/sda, /dev/nvme0n1) and displays their attributes such as size, type, mount point, and model in a tree-like format by reading the sysfs filesystem. E (blkid) is correct because it shows block device attributes like UUID, filesystem type, and LABEL by querying the libblkid library, which reads metadata directly from the device.

Answer

fdisk -l

Answer

du

Answer

df

Question 15

A junior admin receives a ticket: 'The /var partition is filling up quickly. The server has an extra 100GB disk /dev/sdb. The /var filesystem is on logical volume lv_var in volume group vg_system. Currently, vg_system has no free extents. The admin's plan: create a new physical volume on /dev/sdb, extend vg_system, extend lv_var, and resize the filesystem. He runs: pvcreate /dev/sdb; vgextend vg_system /dev/sdb; lvextend -L+100G /dev/vg_system/lv_var; resize2fs /dev/vg_system/lv_var. The system reports error: 'resize2fs: Invalid argument while trying to open /dev/vg_system/lv_var'. What is the most likely mistake?

Accepted Answer

He used resize2fs instead of xfs_growfs because /var is typically XFS.. Option D is correct because the error 'resize2fs: Invalid argument while trying to open /dev/vg_system/lv_var' indicates that the filesystem on lv_var is not ext2/3/4 but likely XFS. RHEL 8/9 defaults to XFS for /var, and XFS requires xfs_growfs (which operates on a mount point, not a block device) instead of resize2fs. Using resize2fs on an XFS filesystem produces this exact error.

Answer

He should have used lvresize instead of lvextend.

Answer

He forgot to run partprobe after pvcreate.

Answer

The lvextend command failed because vg_system has no free extents.