LFCS Storage Management Practice Test 2 — 15 Questions

Question 1

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?

Accepted Answer

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.. Option C is correct because it follows the proper procedure to add a new physical disk to an existing LVM volume group, extend the logical volume, and then grow the XFS filesystem online without unmounting or rebooting. The `xfs_growfs` command is specifically designed to expand an XFS filesystem while it is mounted, which is essential for a production database server that cannot be rebooted.

Answer

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.

Answer

Shrink other logical volumes in vg_data that are not important to free up space, then extend lv_data.

Answer

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.

Question 2

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?

Accepted Answer

mkfs.ext4 -m 2 /dev/sdb1. Option A is correct because the `-m` flag in `mkfs.ext4` sets the reserved block percentage for the superuser, and specifying `-m 2` overrides the default of 5% to reserve only 2% of the blocks on the new ext4 filesystem on /dev/sdb1.

Answer

mkfs.ext4 -R 2 /dev/sdb1

Answer

mkfs.ext4 -r 2 /dev/sdb1

Answer

tune2fs -m 2 /dev/sdb1

Question 3

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

Accepted Answer

mount -o hard,intr server:/export /mnt. Option B is correct because the `mount` command with `-o hard,intr` specifies NFS-specific mount options: `hard` ensures that NFS operations retry indefinitely until the server responds, and `intr` allows signals to interrupt a hung NFS operation. The command `mount -o hard,intr server:/export /mnt` uses the default NFS version (typically NFSv3) and is a valid method to mount an NFS filesystem on a client.

Answer

echo 'server:/export /mnt nfs defaults 0 0' >> /etc/fstab && mount -a

Answer

mount -t cifs server:/share /mnt

Question 4

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

Accepted Answer

mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1. Option B is correct because RAID 1 (mirroring) requires exactly two devices to provide redundancy by duplicating data across both disks. The `--level=1` parameter specifies RAID 1, and `--raid-devices=2` matches the two partitions /dev/sdb1 and /dev/sdc1.

Answer

mdadm --create /dev/md0 --level=5 --raid-devices=2 /dev/sdb1 /dev/sdc1

Answer

mdadm --create /dev/md0 --level=10 --raid-devices=2 /dev/sdb1 /dev/sdc1

Answer

mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sdb1 /dev/sdc1

Question 5

Order the steps to configure a cron job that runs a script every day at 2 AM.

Question 6

Match each Linux package management command to its distribution.

Question 7

A Linux administrator needs to view the UUID and filesystem type of all block devices. Which command provides this information?

Accepted Answer

blkid. The `blkid` command is the correct tool because it directly queries the kernel's block device attributes via the libblkid library, displaying the UUID, filesystem type (e.g., ext4, xfs), and other metadata (like LABEL or PARTUUID) for all block devices. It reads from the `/dev/disk/by-uuid/` symlinks and the kernel's device mapper, making it the standard utility for this specific task.

Answer

/proc/partitions

Answer

ls -l /dev

Answer

fdisk -l

Question 8

An administrator wants to see the disk usage of the /var directory in a human-readable format. Which command should be used?

Accepted Answer

du -sh /var. The `du -sh /var` command is correct because `du` (disk usage) estimates file and directory space usage, and the `-s` flag summarizes the total for `/var` while `-h` provides human-readable output (e.g., KiB, MiB, GiB). This directly shows the disk space consumed by the `/var` directory and its contents.

Answer

df -h /var

Answer

fdisk -l /var

Answer

ls -lh /var

Question 9

A system administrator needs to partition a new 2TB disk using GPT. Which tool should be used?

Accepted Answer

parted. Parted is the correct tool because it explicitly supports GPT partition tables on disks larger than 2TB, whereas fdisk and cfdisk traditionally use MBR (which is limited to 2TB) and sfdisk is primarily a script-based tool that, while it can handle GPT, is not the standard interactive tool for initial partitioning of a new 2TB GPT disk. Parted provides both interactive and scriptable modes and is designed to handle modern partition table formats like GPT.

Answer

cfdisk

Answer

fdisk

Answer

sfdisk

Question 10

An administrator has created an LVM thin pool. Which command should be used to create a thin logical volume named 'thinvol' of size 100GB from the thin pool 'pool1' in volume group 'vg1'?

Accepted Answer

lvcreate -V 100G -T vg1/pool1 --name thinvol. Option C is correct because the `lvcreate` command for thin logical volumes requires the `-V` flag to specify the virtual size of the thin volume and the `-T` flag to reference the thin pool. The syntax `-V 100G -T vg1/pool1 --name thinvol` correctly creates a thin logical volume named 'thinvol' with a virtual size of 100GB from the thin pool 'pool1' in volume group 'vg1'.

Answer

lvcreate -L 100G -n thinvol vg1

Answer

lvcreate -s vg1/pool1 -n thinvol

Answer

lvcreate -L 100G -T vg1/pool1 --name thinvol

Question 11

An administrator needs to configure software RAID 5 on three disks /dev/sda, /dev/sdb, /dev/sdc with a spare disk /dev/sdd. Which command correctly creates the RAID array?

Accepted Answer

mdadm --create /dev/md0 --level=5 --raid-devices=3 --spare-devices=1 /dev/sda /dev/sdb /dev/sdc /dev/sdd. Option A is correct because it uses the `--spare-devices=1` flag to designate `/dev/sdd` as a hot spare, while `--raid-devices=3` specifies that only three disks form the active RAID 5 array. The spare disk is listed after the active disks, which is the correct syntax for `mdadm --create`.

Answer

mdadm --create /dev/md0 --level=5 --raid-devices=4 /dev/sda /dev/sdb /dev/sdc /dev/sdd

Answer

mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sda /dev/sdb /dev/sdc

Answer

mdadm --create /dev/md0 --level=5 --raid-devices=3 --spare-devices=1 /dev/sda /dev/sdb /dev/sdc --spare /dev/sdd

Question 12

An administrator needs to set the reserved block percentage on an ext4 filesystem to 1% for a non-root filesystem. Which command accomplishes this?

Accepted Answer

tune2fs -m 1 /dev/sdb1. Option B is correct because the `tune2fs -m` command sets the reserved block percentage for an ext4 filesystem, and `-m 1` sets it to exactly 1%. This is the standard way to adjust reserved space on a non-root ext4 filesystem, as root filesystems typically have a default of 5% reserved for system processes.

Answer

tune2fs -m 0.5 /dev/sdb1

Answer

tune2fs -r 1% /dev/sdb1

Answer

tune2fs -c 1 /dev/sdb1

Question 13

An admin notices a PV in a VG has failed. The VG is still accessible with redundancy. Which command sequence should be used to replace the faulty PV with a new one (/dev/sde) while the VG is active and without data loss?

Accepted Answer

pvcreate /dev/sde; vgextend VG_name /dev/sde; pvmove /dev/sdb /dev/sde; vgreduce VG_name /dev/sdb. Option C is correct because it first creates the new PV on /dev/sde, extends the VG to include it, then uses pvmove to migrate data from the failing PV (/dev/sdb) to the new PV while the VG is active, and finally removes the faulty PV from the VG with vgreduce. This sequence ensures no data loss and maintains VG availability throughout the replacement process.

Answer

pvcreate /dev/sde; vgreduce VG_name /dev/sdb; vgextend VG_name /dev/sde; pvmove /dev/sdb

Answer

pvcreate /dev/sde; pvmove /dev/sdb /dev/sde; vgextend VG_name /dev/sde; vgreduce VG_name /dev/sdb

Answer

vgreduce --removemissing VG_name; pvcreate /dev/sde; vgextend VG_name /dev/sde; pvmove /dev/sde

Question 14

An administrator receives an alert that the /var/log partition is 95% full. The partition is an LVM logical volume. The volume group has available free extents. Which of the following is the most efficient method to increase the size of the filesystem to 120GB (from current 100GB) without unmounting it?

Accepted Answer

lvextend -L +20G /dev/vg/log; resize2fs /dev/vg/log. Option C is correct because the partition is an LVM logical volume with an ext4 filesystem (implied by the use of resize2fs). The `lvextend -L +20G` command adds 20GB to the existing 100GB volume, making it 120GB, and `resize2fs /dev/vg/log` resizes the ext4 filesystem online without unmounting. This is the most efficient method as it uses relative sizing and the correct filesystem-specific resize tool.

Answer

lvextend -L 20G /dev/vg/log; resize2fs /dev/vg/log

Answer

lvextend -L +20G /dev/vg/log; xfs_growfs /data

Answer

lvextend -L 120G /dev/vg/log; resize2fs /dev/vg/log

Question 15

A storage administrator wants to create a software RAID 10 (1+0) array using six disks. Which mdadm command is appropriate?

Accepted Answer

mdadm --create /dev/md0 --level=10 --raid-devices=6 /dev/sd[abcdef]. Option B is correct because it uses the proper mdadm syntax to create a RAID 10 array with six disks. The --level=10 specifies RAID 10 (a striped mirror set), and --raid-devices=6 matches the number of disks provided via the /dev/sd[abcdef] glob, which expands to /dev/sda through /dev/sdf. This command correctly creates a RAID 10 array that combines striping and mirroring across all six devices.

Answer

mdadm --create /dev/md0 --level=10 --raid-devices=6 /dev/sda /dev/sdb /dev/sdc

Answer

mdadm --create /dev/md0 --level=1 --raid-devices=6 --chunk=64 /dev/sd[abcdef]

Answer

mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/sda /dev/sdb /dev/sdc /dev/sdd