Storage Management practice questions

A system administrator is tasked with setting up a new 2TB disk for a database server. The database requires high read/write performance and redundancy. The server has a hardware RAID controller, but the administrator wants to use Linux software RAID for flexibility. Which of the following RAID levels should the administrator choose to maximize performance while providing fault tolerance, assuming the disk will be part of a larger array in the future?

Trap 1: RAID 5

RAID 5 has write performance penalty due to parity calculation.

Trap 2: RAID 0

RAID 0 offers no fault tolerance, data loss if one disk fails.

Trap 3: RAID 6

RAID 6 has even greater write penalty than RAID 5.

A
RAID 5
Why wrong: RAID 5 has write performance penalty due to parity calculation.
B
RAID 0
Why wrong: RAID 0 offers no fault tolerance, data loss if one disk fails.
C
RAID 6
Why wrong: RAID 6 has even greater write penalty than RAID 5.
D
RAID 10
RAID 10 combines mirroring and striping for performance and redundancy.

Question 2easymultiple choice

An administrator wants to extend a logical volume named 'lv_data' in volume group 'vg_data' by 5GB. The volume group has free physical extents. Which command should be used?

Trap 1: pvextend -L +5G /dev/vg_data/lv_data

pvextend is for physical volumes, not logical volumes.

Trap 2: lvresize -L +5G /dev/vg_data/lv_data

lvresize is not a standard command.

Trap 3: lvextend -L 5G /dev/vg_data/lv_data

This sets the size to 5GB, not extends by 5GB.

A
pvextend -L +5G /dev/vg_data/lv_data
Why wrong: pvextend is for physical volumes, not logical volumes.
B
lvextend -L +5G /dev/vg_data/lv_data
The + sign indicates adding space.
C
lvresize -L +5G /dev/vg_data/lv_data
Why wrong: lvresize is not a standard command.
D
lvextend -L 5G /dev/vg_data/lv_data
Why wrong: This sets the size to 5GB, not extends by 5GB.

Question 3hardmultiple choice

A storage administrator notices that a newly created XFS filesystem on a logical volume shows only 90% of the expected capacity. The logical volume is 100GB. What is the most likely cause?

Trap 1: The disk has bad blocks that were marked as unusable.

Bad blocks are not typically the cause of a consistent 10% reduction.

Trap 2: The volume group has insufficient physical extents.

The logical volume was created successfully, so VG has enough extents.

Trap 3: The filesystem is mounted with the 'noatime' option.

Mount options do not affect capacity.

A
The disk has bad blocks that were marked as unusable.
Why wrong: Bad blocks are not typically the cause of a consistent 10% reduction.
B
The filesystem was created with a reduced size due to mkfs.xfs default settings.
XFS reserves space for metadata; mkfs.xfs may not use full device if size is not specified.
C
The volume group has insufficient physical extents.
Why wrong: The logical volume was created successfully, so VG has enough extents.
D
The filesystem is mounted with the 'noatime' option.
Why wrong: Mount options do not affect capacity.

Question 4easymultiple choice

Which command can be used to display the UUID of a filesystem on /dev/sdb1?

Trap 1: tune2fs -l /dev/sdb1

tune2fs works only on ext filesystems and requires root.

Trap 2: df -h /dev/sdb1

df shows disk usage, not UUID.

Trap 3: lsblk /dev/sdb1

lsblk shows block device info but not UUID by default.

A
blkid /dev/sdb1
blkid displays UUID and filesystem type.
B
tune2fs -l /dev/sdb1
Why wrong: tune2fs works only on ext filesystems and requires root.
C
df -h /dev/sdb1
Why wrong: df shows disk usage, not UUID.
D
lsblk /dev/sdb1
Why wrong: lsblk shows block device info but not UUID by default.

Question 5mediummultiple choice

An administrator needs to mount an XFS filesystem with options to optimize for a database workload. Which mount option would reduce metadata updates to improve performance?

Trap 1: noexec

Prevents execution of binaries, does not reduce metadata updates.

Trap 2: nodiratime

Disables atime updates for directories only, but noatime is more comprehensive.

Trap 3: relatime

Relatime updates atime conditionally, but not as effective as noatime.

A
noexec
Why wrong: Prevents execution of binaries, does not reduce metadata updates.
B
nodiratime
Why wrong: Disables atime updates for directories only, but noatime is more comprehensive.
C
relatime
Why wrong: Relatime updates atime conditionally, but not as effective as noatime.
D
noatime
Disables atime updates, reducing metadata writes.

Question 6mediummulti select

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

Trap 1: mkfs.ext4 /dev/sdb1

mkfs creates a filesystem, not a PV.

Trap 2: pvresize /dev/sdb1

pvresize resizes an existing PV.

Trap 3: pvdisplay /dev/sdb1

pvdisplay shows information, does not create.

A
mkfs.ext4 /dev/sdb1
Why wrong: mkfs creates a filesystem, not a PV.
B
pvresize /dev/sdb1
Why wrong: pvresize resizes an existing PV.
C
pvcreate /dev/sdb1
pvcreate directly initializes a physical volume.
D
fdisk /dev/sdb (then set type to 8e)
fdisk can create an LVM partition that can later be used by pvcreate.
E
pvdisplay /dev/sdb1
Why wrong: pvdisplay shows information, does not create.

Question 7hardmulti select

Which THREE are valid reasons to use a swap file instead of a swap partition? (Choose three.)

Trap 1: Required for hibernation (suspend-to-disk).

Hibernation requires a swap partition.

Trap 2: Faster performance than swap partition.

Swap files may have slightly more overhead due to filesystem layer.

A
Can be placed on a filesystem that supports sparse files.
Sparse files save space until used.
B
Required for hibernation (suspend-to-disk).
Why wrong: Hibernation requires a swap partition.
C
Easier to manage in virtualized environments.
Adding a swap file is simpler than modifying virtual disk partitions.
D
Faster performance than swap partition.
Why wrong: Swap files may have slightly more overhead due to filesystem layer.
E
Easier to resize without repartitioning.
Swap files can be easily resized by removing and recreating with new size.

Question 8hardmultiple choice

You are a Linux administrator at a mid-sized company. The company runs a critical PostgreSQL database on a server running CentOS 7. The database stores its data on a 500GB logical volume (lv_pgdata) in volume group vg_pg. The filesystem is XFS. Recently, the database team reports that write performance is degrading, and the disk is nearly full (95% usage). You have added a new 200GB SSD to the server, and you need to increase the storage capacity and improve write performance for the database. The database can tolerate a brief downtime (less than 5 minutes) for maintenance. You want to use LVM to add the new SSD as a physical volume, extend the volume group, and then extend the logical volume and filesystem. Additionally, you want to improve write performance by placing the frequently written database transaction log on a separate faster storage. However, the database configuration expects the transaction log to be in a subdirectory of the data directory. You have the following options: A. Create a new logical volume for the transaction log, format it as XFS, mount it on the data directory's subdirectory, and move the log files. B. Add the SSD as a PV, extend vg_pg, extend lv_pgdata, and then use LVM's pvmove to move all extents to the SSD. C. Add the SSD as a PV, create a new VG, create a new LV for the transaction log, format as ext4, mount, and reconfigure the database. D. Use LVM's striping (RAID 0) across the existing HDD and new SSD to improve performance, then extend the filesystem. Which option best meets the requirements of increasing capacity and improving write performance with minimal downtime?

Trap 1: Add the SSD as a PV, extend vg_pg, extend lv_pgdata and resize the…

This does not increase capacity (still 500GB) and wastes the HDD.

Trap 2: Use LVM's striping (RAID 0) across the existing HDD and new SSD to…

Striping increases risk of data loss if either disk fails, and requires data migration.

Trap 3: Add the SSD as a PV, create a new VG and LV for the transaction…

Creating a separate VG is unnecessary and ext4 may not be optimal for database logs.

A
Add the SSD as a PV, extend vg_pg, extend lv_pgdata and resize the filesystem for capacity. Then create a new LV on the SSD, format as XFS, mount it on the transaction log subdirectory, move the log files, and update the database configuration to point to the new location.
This increases capacity and isolates log writes to SSD, improving performance with minimal downtime.
B
Add the SSD as a PV, extend vg_pg, extend lv_pgdata and resize the filesystem for capacity. Then use pvmove to move all data to the SSD, leaving the HDD unused.
Why wrong: This does not increase capacity (still 500GB) and wastes the HDD.
C
Use LVM's striping (RAID 0) across the existing HDD and new SSD to improve performance, then extend the filesystem.
Why wrong: Striping increases risk of data loss if either disk fails, and requires data migration.
D
Add the SSD as a PV, create a new VG and LV for the transaction log, format as ext4, mount, and reconfigure the database to use the new location.
Why wrong: Creating a separate VG is unnecessary and ext4 may not be optimal for database logs.

Question 9mediummultiple choice

A system administrator notices that a new 500GB SSD (/dev/sdb) is not being recognized by the system after installation. The server uses UEFI and GPT partitioning. Which command should the administrator run first to verify that the disk is detected by the kernel?

Trap 1: fdisk -l /dev/sdb

fdisk -l would work but requires root and is not the first step; lsblk is simpler.

Trap 2: cat /proc/cpuinfo

This shows CPU info, not disk detection.

Trap 3: lsusb

lsusb lists USB devices, but /dev/sdb may be SATA/SAS, not USB.

A
fdisk -l /dev/sdb
Why wrong: fdisk -l would work but requires root and is not the first step; lsblk is simpler.
B
lsblk
lsblk lists all block devices, including /dev/sdb, and does not require root.
C
cat /proc/cpuinfo
Why wrong: This shows CPU info, not disk detection.
D
lsusb
Why wrong: lsusb lists USB devices, but /dev/sdb may be SATA/SAS, not USB.

Question 10hardmultiple choice

A Linux administrator needs to create a RAID 5 array using three disks: /dev/sdb, /dev/sdc, and /dev/sdd, each 2TB. The administrator wants to ensure the array can be reassembled automatically after a reboot. Which command should be used to create the array?

Trap 1: mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb…

Metadata 0.90 has a 2TB total limit; each disk 2TB would exceed.

Trap 2: mdadm --create /dev/md0 --level=1 --raid-devices=3 /dev/sdb…

This creates RAID 1 (mirror), not RAID 5.

Trap 3: mdadm --create /dev/md0 --level=0 --raid-devices=3 /dev/sdb…

This creates RAID 0, not RAID 5.

A
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd --metadata=0.90
Why wrong: Metadata 0.90 has a 2TB total limit; each disk 2TB would exceed.
B
mdadm --create /dev/md0 --level=1 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd
Why wrong: This creates RAID 1 (mirror), not RAID 5.
C
mdadm --create /dev/md0 --level=0 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd
Why wrong: This creates RAID 0, not RAID 5.
D
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd --metadata=1.2
Correct for RAID 5 with metadata 1.2, supporting large disks and auto-assembly.

Question 11easymulti select

Which TWO commands can be used to mount a filesystem on /dev/sdb1 to /mnt/data?

Trap 1: mount /mnt/data /dev/sdb1

Arguments reversed: device then mount point.

Trap 2: mount -o loop /dev/sdb1 /mnt/data

-o loop is for loop devices (files), not block devices.

Trap 3: mount -t auto /dev/sdb1 /mnt/data -o loop

Loop option not needed for block devices.

A
mount /mnt/data /dev/sdb1
Why wrong: Arguments reversed: device then mount point.
B
mount /dev/sdb1 /mnt/data
Standard mount command; works if filesystem is recognized.
C
mount -t ext4 /dev/sdb1 /mnt/data
Specifies filesystem type and works.
D
mount -o loop /dev/sdb1 /mnt/data
Why wrong: -o loop is for loop devices (files), not block devices.
E
mount -t auto /dev/sdb1 /mnt/data -o loop
Why wrong: Loop option not needed for block devices.

Question 12mediummulti select

Which THREE of the following are valid Linux filesystem types that can be used for root partitions on a modern Linux system?

Trap 1: NTFS

Primarily Windows; Linux support is not native for root.

Trap 2: FAT32

FAT32 lacks permissions and is not used for root.

A
XFS
Scalable, used in RHEL/CentOS.
B
NTFS
Why wrong: Primarily Windows; Linux support is not native for root.
C
FAT32
Why wrong: FAT32 lacks permissions and is not used for root.
D
Btrfs
Modern filesystem with snapshots, used in some distros.
E
ext4
Default for many distros, fully supported.

Question 13mediummultiple choice

After extending the logical volume, the df output still shows 100G. What is the most likely reason?

Exhibit

Refer to the exhibit.

# df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/mapper/vg_data-lv_data  100G   50G   50G  50% /data

# lvextend -L +10G /dev/mapper/vg_data-lv_data
  Size of logical volume vg_data/lv_data changed from 100.00 GiB to 110.00 GiB.
  Logical volume vg_data/lv_data successfully resized.

# df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/mapper/vg_data-lv_data  100G   50G   50G  50% /data

Trap 1: lvresize must be used instead of lvextend.

lvextend is correct; lvresize is similar.

Trap 2: The kernel has not detected the new size; reboot required.

Kernel can detect changes without reboot.

Trap 3: The mount point must be remounted with the 'remount' option.

Remounting does not resize filesystem.

A
The filesystem on the logical volume has not been resized.
Need to run resize2fs or xfs_growfs.
B
lvresize must be used instead of lvextend.
Why wrong: lvextend is correct; lvresize is similar.
C
The kernel has not detected the new size; reboot required.
Why wrong: Kernel can detect changes without reboot.
D
The mount point must be remounted with the 'remount' option.
Why wrong: Remounting does not resize filesystem.

Question 14easymultiple choice

A system administrator receives an alert that disk /dev/sda is predicted to fail soon. The server uses LVM, and /dev/sda is part of a volume group named vg_system. Which of the following is the best course of action to replace the failing disk without downtime?

Trap 1: Use dd to clone /dev/sda to a new disk and then replace.

dd may cause downtime and I/O errors.

Trap 2: Use ddrescue to copy data, then replace the disk.

ddrescue is for failing disks but does not handle LVM metadata well.

Trap 3: Remove /dev/sda from the volume group and add a new disk.

Removing without moving data first causes loss.

A
Use dd to clone /dev/sda to a new disk and then replace.
Why wrong: dd may cause downtime and I/O errors.
B
Use ddrescue to copy data, then replace the disk.
Why wrong: ddrescue is for failing disks but does not handle LVM metadata well.
C
Remove /dev/sda from the volume group and add a new disk.
Why wrong: Removing without moving data first causes loss.
D
Use pvmove to move physical extents to another disk, then remove the old disk.
pvmove safely relocates data online.

Question 15hardmultiple choice

The administrator wants to create a new logical volume of 5GB for /var/log. Which of the following is the most appropriate first step?

Network Topology

Trap 1: Use lvresize to shrink lv_root by 5G and then create lv_var_log

Shrinking root LV is risky and not straightforward.

Trap 2: Mount a new filesystem directly on a new partition /dev/sdc1

No new disk is mentioned; also not using LVM.

Trap 3: Use lvcreate -L 5G vg_root -n lv_var_log

vg_root has no free space.

A
Use lvresize to shrink lv_root by 5G and then create lv_var_log
Why wrong: Shrinking root LV is risky and not straightforward.
B
Add a new disk (e.g., /dev/sdc) to the system, create a PV, and extend vg_root.
This provides free space to create the new LV.
C
Mount a new filesystem directly on a new partition /dev/sdc1
Why wrong: No new disk is mentioned; also not using LVM.
D
Use lvcreate -L 5G vg_root -n lv_var_log
Why wrong: vg_root has no free space.

Question 16hardmultiple choice

Your company runs a critical database server that uses a 2TB XFS filesystem mounted at /data. The filesystem resides on an LVM logical volume (lv_data) within a volume group (vg_data) that spans four physical volumes (each 600GB SSD). You have been receiving low-space alerts: /data is at 95% capacity. After reviewing usage, you determine that the database will need an additional 500GB within the next month. The server has no additional physical disks available, but there is an unused 1TB SSD in inventory that you can install. However, the server is in production and cannot be rebooted. The system uses a 5.10 Linux kernel. Which of the following is the best approach to increase the available space for /data?

Trap 1: Create a RAID 0 array with the existing SSDs and the new SSD using…

RAID 0 would require rebuilding and data migration; not simple expansion.

Trap 2: Shrink other logical volumes in vg_data that are not important to…

Shrinking XFS is not supported online; also may not free enough space.

Trap 3: Backup /data to an external drive, delete the logical volume,…

Unnecessary downtime and data restoration risk.

A
Create a RAID 0 array with the existing SSDs and the new SSD using mdadm, then format with XFS and mount at a different mount point, then move data.
Why wrong: RAID 0 would require rebuilding and data migration; not simple expansion.
B
Shrink other logical volumes in vg_data that are not important to free up space, then extend lv_data.
Why wrong: Shrinking XFS is not supported online; also may not free enough space.
C
Install the new SSD, create a partition with fdisk, run pvcreate, vgextend vg_data, lvextend -L +500G /dev/vg_data/lv_data, and then run xfs_growfs /data.
Online expansion of XFS is supported; all steps are non-disruptive.
D
Backup /data to an external drive, delete the logical volume, volume group, and physical volumes, then recreate everything including the new SSD to have a single large filesystem, then restore data.
Why wrong: Unnecessary downtime and data restoration risk.

Question 17mediummultiple choice

A system administrator needs to create a new ext4 filesystem on /dev/sdb1 with a reserved block percentage of 2% instead of the default 5%. Which command should be used?

Trap 1: mkfs.ext4 -R 2 /dev/sdb1

Incorrect: -R is not a valid option for mkfs.ext4.

Trap 2: mkfs.ext4 -r 2 /dev/sdb1

Incorrect: -r is for RAID stride.

Trap 3: tune2fs -m 2 /dev/sdb1

Incorrect: tune2fs modifies an existing filesystem, not creation.

A
mkfs.ext4 -m 2 /dev/sdb1
Correct: -m sets reserved blocks percentage.
B
mkfs.ext4 -R 2 /dev/sdb1
Why wrong: Incorrect: -R is not a valid option for mkfs.ext4.
C
mkfs.ext4 -r 2 /dev/sdb1
Why wrong: Incorrect: -r is for RAID stride.
D
tune2fs -m 2 /dev/sdb1
Why wrong: Incorrect: tune2fs modifies an existing filesystem, not creation.

Question 18hardmulti select

Which THREE of the following are valid methods to mount an NFS filesystem on a client?

Trap 1: echo 'server:/export /mnt nfs defaults 0 0' >> /etc/fstab && mount…

Incorrect: mount -a reads /etc/fstab but the command as written is incomplete; also mount -a alone is not a mount method.

Trap 2: mount -t cifs server:/share /mnt

Incorrect: -t cifs is for CIFS, not NFS.

A
echo 'server:/export /mnt nfs defaults 0 0' >> /etc/fstab && mount -a
Why wrong: Incorrect: mount -a reads /etc/fstab but the command as written is incomplete; also mount -a alone is not a mount method.
B
mount -o hard,intr server:/export /mnt
Correct: NFS mount with options.
C
mount -t cifs server:/share /mnt
Why wrong: Incorrect: -t cifs is for CIFS, not NFS.
D
mount -t nfs server:/export /mnt
Correct: Explicit NFS type.
E
mount -t nfs4 server:/export /mnt
Correct: NFSv4 type.

Question 19easymultiple choice

Refer to the exhibit. The administrator wants to create a RAID 1 array using /dev/sdb1 and /dev/sdc1. Which command should be used?

Exhibit

Refer to the exhibit.

# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0   20G  0 disk
├─sda1   8:1    0    1G  0 part /boot
├─sda2   8:2    0   10G  0 part /
└─sda3   8:3    0    9G  0 part [SWAP]
sdb      8:16   0   10G  0 disk
└─sdb1   8:17   0   10G  0 part
sdc      8:32   0    5G  0 disk
└─sdc1   8:33   0    5G  0 part /data

Trap 1: mdadm --create /dev/md0 --level=5 --raid-devices=2 /dev/sdb1…

Incorrect: RAID 5 needs at least 3 devices.

Trap 2: mdadm --create /dev/md0 --level=10 --raid-devices=2 /dev/sdb1…

Incorrect: RAID 10 needs at least 4 devices.

Trap 3: mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sdb1…

Incorrect: level=0 creates RAID 0, not RAID 1.

A
mdadm --create /dev/md0 --level=5 --raid-devices=2 /dev/sdb1 /dev/sdc1
Why wrong: Incorrect: RAID 5 needs at least 3 devices.
B
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1
Correct: RAID 1 requires level=1.
C
mdadm --create /dev/md0 --level=10 --raid-devices=2 /dev/sdb1 /dev/sdc1
Why wrong: Incorrect: RAID 10 needs at least 4 devices.
D
mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sdb1 /dev/sdc1
Why wrong: Incorrect: level=0 creates RAID 0, not RAID 1.

Question 20mediumdrag order