EX200 Configure local storage Practice Test 5 — 15 Questions

Question 1

A storage administrator is asked to increase the size of an ext4 filesystem mounted at /data. The underlying logical volume /dev/mapper/vg01-lv01 is currently 10GB and the volume group has 5GB of free extents. After extending the logical volume by 2GB using lvextend -L +2G /dev/mapper/vg01-lv01, what command must be run to resize the filesystem?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

resize2fs /dev/mapper/vg01-lv01. After extending the logical volume with `lvextend`, the filesystem does not automatically recognize the new space. For ext4 filesystems, the `resize2fs` command must be run to resize the filesystem to use the additional logical volume capacity. This command can be executed online (while the filesystem is mounted) and will expand the filesystem to fill the available space in the logical volume.

Answer

lvextend -r -L +2G /dev/mapper/vg01-lv01

Answer

xfs_growfs /data

Answer

fsck -f /dev/mapper/vg01-lv01

Question 2

An administrator needs to add a 2GB swap partition to an existing disk (/dev/sdc) that already has one partition. The administrator creates a second primary partition using fdisk and sets the type to Linux swap (82). Which command completes the setup to enable swap?

Accepted Answer

mkswap /dev/sdc2 && swapon /dev/sdc2. After creating the partition with fdisk and setting the type to 82 (Linux swap), the partition must be formatted as a swap area using `mkswap` before it can be activated. The `swapon` command then enables the swap space. Option C correctly chains `mkswap /dev/sdc2` to initialize the swap signature and `swapon /dev/sdc2` to activate it.

Answer

swapon /dev/sdc2

Answer

mkfs.swap /dev/sdc2 && swapon /dev/sdc2

Answer

mkswap /dev/sdc && swapon /dev/sdc

Question 3

A technician is configuring a new Red Hat Enterprise Linux 9 server with multiple disks. They need to create a RAID 1 array using /dev/sda and /dev/sdb for the /boot partition. Which tool can create the RAID array and enable booting from it?

Accepted Answer

Use mdadm to create a RAID1 device and install GRUB on both disks. Mdadm is the standard Linux tool for creating software RAID arrays, including RAID 1 (mirroring). For the /boot partition, which must be readable by the bootloader, GRUB must be installed on both disks in the RAID 1 array to ensure bootability if one disk fails. mdadm creates the RAID device, and GRUB can then be installed on each disk's MBR or GPT partition.

Answer

Use parted to create a RAID array directly by specifying the RAID level

Answer

Use fdisk to create a RAID partition and then format with ext4

Answer

Use LVM to create a mirrored logical volume for /boot

Question 4

A system has a logical volume that is thinly provisioned. The thin pool has a size of 100GB and the thin volume has a virtual size of 500GB. The administrator notices that the thin pool has only 5GB of data written so far. Which command will display the current data usage of the thin volume?

Accepted Answer

lvs -o lv_name,data_percent. The `lvs -o lv_name,data_percent` command specifically displays the percentage of the thin pool that has been consumed by the thinly provisioned logical volume. For thin volumes, the `data_percent` field reports the actual data usage relative to the thin pool's capacity, which is exactly what the administrator needs to see the current 5GB usage against the 100GB pool.

Answer

df -h /dev/mapper/vg01-thinvol

Answer

lsblk /dev/mapper/vg01-thinvol

Answer

lvdisplay /dev/vg01/thinvol

Question 5

An administrator wants to mount an existing ext4 filesystem from /dev/sdb1 to /mnt/data at boot time. What entry should be added to /etc/fstab?

Accepted Answer

/dev/sdb1  /mnt/data  ext4  defaults  0  0. It specifies the correct device (/dev/sdb1), the correct mount point (/mnt/data), the correct filesystem type (ext4), and the correct mount options (defaults) for an ext4 filesystem to be mounted at boot. The /etc/fstab entry must include all six fields in order: device, mount point, filesystem type, options, dump, and pass.

Answer

/dev/sdb1  /mnt/data  xfs  defaults  0  0

Answer

LABEL=data  ext4  defaults  0  0

Answer

/dev/sdb1  /data  ext4  defaults  0  0

Question 6

A database server experiences high disk I/O wait times. The administrator runs 'iostat -x 1' and sees that the avgqu-sz for /dev/sda is 25 and await is 200 ms. The disk is a single 7200 RPM SATA drive. Which action is most likely to improve performance?

Accepted Answer

Replace the drive with an SSD or add additional drives in RAID 10. The high avgqu-sz (25) and await (200 ms) indicate the single 7200 RPM SATA drive is saturated, as its maximum IOPS is typically around 75-100 random I/O operations per second. Replacing it with an SSD (which can handle thousands of IOPS) or adding drives in RAID 10 (which increases IOPS through parallelism) directly addresses the hardware bottleneck. No software tuning can overcome the physical limitations of a single spinning disk under heavy I/O load.

Answer

Increase the read-ahead buffer using blockdev --setra

Answer

Change the I/O scheduler from CFQ to noop

Answer

Run 'fsck -f' on the filesystem to check for fragmentation

Question 7

An administrator attempts to mount an XFS filesystem from /dev/sdc1 to /mnt/archive but receives the error: 'mount: /mnt/archive: wrong fs type, bad option, bad superblock on /dev/sdc1, missing codepage or helper program, or other error.' The output of 'dumpe2fs /dev/sdc1' shows 'dumpe2fs: Bad magic number in super-block while trying to open /dev/sdc1'. What is the most likely problem?

Accepted Answer

The filesystem on /dev/sdc1 is XFS, not ext4. The error message 'wrong fs type' combined with 'dumpe2fs: Bad magic number in super-block' indicates that the filesystem on /dev/sdc1 is not an ext2/3/4 filesystem. dumpe2fs is designed to read ext2/3/4 superblocks, and the 'bad magic number' error means it cannot find a valid ext superblock. Since the administrator is trying to mount an XFS filesystem, the correct tool to examine it is xfs_db or xfs_info, not dumpe2fs. Therefore, the most likely problem is that the filesystem is XFS, not ext4.

Answer

The mount point /mnt/archive does not exist

Answer

The XFS kernel module is not loaded

Answer

The partition /dev/sdc1 does not exist

Question 8

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. 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 9

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. 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 10

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 11

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. 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 12

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. 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 13

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 exec,remount /dev/sdc1 /mnt/backup. Both options B and C are valid commands to remount a filesystem with the exec option without unmounting. Option B specifies both the device and mount point, which is accepted by the mount command when using the remount option. Option C uses only the mount point, which is also sufficient. The remount option allows changing mount options on a live filesystem. Options A and D are invalid: A unmounts and remounts, which is not a single remount operation and could cause issues; D attempts to remount all filesystems with exec, which may not apply correctly and does not target the specific filesystem.

Answer

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

Answer

mount -a -o exec

Question 14

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. 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 15

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. 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