EX200 Create and configure file systems — Timed 20 Questions

Question 1

A system administrator needs to create a new ext4 filesystem on /dev/sdb1 and mount it persistently at /data. Which set of commands should be used?

Accepted Answer

mkfs -t ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab. Option A is correct because it creates the ext4 filesystem with `mkfs -t ext4 /dev/sdb1`, creates the mount point directory with `mkdir /data`, mounts the filesystem immediately with `mount /dev/sdb1 /data`, and then adds an entry to `/etc/fstab` using the correct format (device, mount point, filesystem type, options, dump, pass) to ensure the mount persists across reboots. The `&&` operator ensures each command only runs if the previous one succeeds, which is a safe practice for scripting this task.

Answer

mkfs.ext4 /dev/sdb1 && mount /dev/sdb1 /data

Answer

mkfs -t ext4 /dev/sdb1 && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab && mount /data

Answer

mkfs.ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && blkid /dev/sdb1 >> /etc/fstab

Question 2

A file server is experiencing slow write performance. The admin suspects the filesystem is nearly full. Which command should be used to check disk usage per partition?

Accepted Answer

df -h. The `df -h` command displays disk space usage for all mounted filesystems in human-readable format (e.g., GB, MB). This directly answers the admin's need to check per-partition usage and identify if a filesystem is nearly full, which can cause slow write performance due to lack of free space.

Answer

df -i

Answer

du -h --max-depth=1 /

Answer

du -sh /

Question 3

A technician attempts to mount an XFS filesystem from /dev/sdc1 to /mnt/backup but receives: 'mount: /mnt/backup: mount point does not exist.' The directory /mnt/backup does exist. What is the most likely cause?

Accepted Answer

SELinux context of /mnt/backup prevents mounting.. The error message 'mount: /mnt/backup: mount point does not exist' is misleading because the directory does exist. The most likely cause is that SELinux is blocking the mount due to a missing or incorrect context on the mount point. SELinux requires the mount point directory to have a specific context (e.g., `default_t` or a context matching the filesystem type) for the mount to succeed; if the context is wrong or missing, the kernel may treat the directory as nonexistent for the mount operation.

Answer

The directory /mnt/backup is not empty.

Answer

The device /dev/sdc1 does not exist.

Answer

The filesystem on /dev/sdc1 is not XFS.

Question 4

An administrator needs to add a 1GB swap partition on /dev/sdd1. Which series of commands accomplishes this?

Accepted Answer

fdisk /dev/sdd, create partition, then mkswap /dev/sdd1, swapon /dev/sdd1, and add to /etc/fstab.. Option D is correct because it includes all necessary steps: first create the partition with fdisk (since /dev/sdd1 does not exist yet), then format it as swap with mkswap, activate it with swapon, and finally add an entry to /etc/fstab to ensure persistence across reboots. The other options omit the critical partition creation step or fail to make the swap permanent.

Answer

mkswap /dev/sdd1 && echo '/dev/sdd1 swap swap defaults 0 0' >> /etc/fstab

Answer

mkfs.swap /dev/sdd1 && swapon /dev/sdd1

Answer

mkswap /dev/sdd1 && swapon /dev/sdd1

Question 5

A filesystem is reported as 'read-only' after a system crash. The admin runs fsck and sees 'clean' status. What is the most likely reason it remains read-only?

Accepted Answer

fsck detected errors but did not fix them automatically.. Option D is correct because when fsck reports a filesystem as 'clean' but the system still shows it as read-only, it typically means fsck detected errors during the check but did not automatically repair them. By default, fsck runs in non-interactive mode on boot and may require the '-y' flag or manual intervention to apply fixes. The 'clean' status can be misleading if the journal indicates no corruption, but underlying metadata inconsistencies remain unaddressed.

Answer

fsck cannot fix errors on ext4 filesystems.

Answer

The filesystem is still mounted; fsck cannot fix it while mounted.

Answer

The filesystem is XFS, and fsck does not repair XFS.

Question 6

A system has two 500GB disks in a RAID1 (mirror) using mdadm. One disk fails. After replacement, what is the correct procedure to restore redundancy?

Accepted Answer

Use sfdisk to copy partition table from /dev/sda to /dev/sdb, then 'mdadm --manage /dev/md0 --add /dev/sdb1'. Option D is correct because when replacing a failed disk in a RAID1 array managed by mdadm, the new disk must have a partition table that matches the surviving disk. Using sfdisk to copy the partition table from /dev/sda to /dev/sdb ensures that the partition layout (e.g., partition type 0xFD for Linux RAID autodetect) is identical, which is required before adding the partition (e.g., /dev/sdb1) to the array with mdadm --manage --add. Simply adding the raw disk without a proper partition table would fail because mdadm expects a partition with the correct RAID superblock and partition type.

Answer

Run 'mdadm --manage /dev/md0 --add /dev/sdb'

Answer

Remove the failed disk with 'mdadm /dev/md0 --fail /dev/sdb1' then add new.

Answer

Run 'mdadm --assemble --scan' to rebuild the array automatically.

Question 7

An admin needs to mount an NFS export from server nfs.example.com:/exports/app to /mnt/app with options for read-only and no root squash. Which command is correct?

Accepted Answer

mount -t nfs -o ro,no_root_squash nfs.example.com:/exports/app /mnt/app. Option A is correct because the `mount -t nfs -o ro,no_root_squash` command mounts the NFS export from `nfs.example.com:/exports/app` to `/mnt/app` as read-only (`ro`) and disables root squash (`no_root_squash`), which allows the root user on the client to retain root privileges when accessing files on the NFS server. The `-t nfs` specifies the NFS filesystem type, and the mount point `/mnt/app` must exist prior to execution.

Answer

mount -t nfs -o ro,root_squash nfs.example.com:/exports/app /mnt/app

Answer

mount -t nfs -o ro,no_root_squash,nosuid nfs.example.com:/exports/app /mnt/app

Answer

mount -t nfs -o rw,no_root_squash nfs.example.com:/exports/app /mnt/app

Question 8

Which command creates an XFS filesystem on /dev/nvme0n1p1 and sets the label to 'data'?

Accepted Answer

mkfs.xfs -L data /dev/nvme0n1p1. Option C is correct because the `-L` flag in `mkfs.xfs` is used to set the filesystem label. The command `mkfs.xfs -L data /dev/nvme0n1p1` creates an XFS filesystem on the specified partition and assigns it the label 'data'.

Answer

mkfs.xfs -l data /dev/nvme0n1p1

Answer

mkfs.xfs -f /dev/nvme0n1p1

Answer

mkfs.xfs -n data /dev/nvme0n1p1

Question 9

Which TWO commands can be used to check the UUID of a filesystem on /dev/sda1?

Accepted Answer

lsblk -o UUID /dev/sda1. The `blkid` command directly queries the UUID of a block device from the libblkid cache or by reading the filesystem superblock, and `lsblk -o UUID` filters the lsblk output to show only the UUID column for the specified device. Both commands reliably retrieve the UUID of /dev/sda1.

Answer

e2label /dev/sda1

Answer

findmnt /dev/sda1

Answer

file -s /dev/sda1

Question 10

Which THREE of the following are valid options for mounting an ext4 filesystem with specific mount options in /etc/fstab?

Accepted Answer

noexec. The `noexec` option prevents execution of binaries on the mounted filesystem, which is a common security hardening measure. It is a valid mount option for ext4 and can be specified in /etc/fstab.

Answer

relatime

Answer

suid

Question 11

Which TWO commands can be used to create a new directory that will serve as a mount point?

Accepted Answer

install -d /mnt/newmount. Option A is correct because `install -d /mnt/newmount` creates the directory `/mnt/newmount` if it does not already exist, setting it up as a mount point. Option D is correct because `mkdir /mnt/newmount` is the standard command to create a directory, which can then be used as a mount point for a filesystem.

Answer

touch /mnt/newmount

Answer

ln -s /mnt /mnt/newmount

Answer

ln /mnt /mnt/newmount

Question 12

After extending the logical volume to 500G, why does df still show 250G?

Accepted Answer

The filesystem was not resized after extending the LV.. Option C is correct because extending a logical volume (LV) with `lvextend` only increases the block device size; the filesystem on top must be resized separately using `resize2fs` (for ext4) or `xfs_growfs` (for XFS). Without this step, the filesystem still sees the original size, so `df` reports 250G instead of 500G.

Answer

The mount point is incorrect.

Answer

The physical volume is full.

Answer

The logical volume extension failed.

Question 13

What is the most likely cause of the mount error?

Accepted Answer

The NFS server IP address is unreachable or the nfs-utils package is not installed.. The mount error is most likely caused by the NFS server being unreachable or the nfs-utils package not being installed. Without the nfs-utils package, the system lacks the necessary NFS client tools (e.g., mount.nfs, rpcbind) to mount NFS shares. If the server IP is unreachable, the mount command will fail with a timeout or 'No route to host' error, which is a common issue when network connectivity or NFS services are not properly configured.

Answer

The entry in /etc/fstab is malformed.

Answer

The filesystem type 'nfs4' is incorrect; should be 'nfs'.

Answer

The mount point /mnt/data does not exist.

Question 14

You are managing a Red Hat Enterprise Linux 9 server that hosts a critical database application. The database stores its data on an XFS filesystem mounted on /data, backed by a logical volume in a volume group named vg_db. Recently, the database team reported that write operations are failing with 'Disk quota exceeded' errors, but the filesystem still shows 40% free space. You check the filesystem quota configuration and find that no user or group quotas are set on /data. The database runs as user 'dbadmin' with group 'dba'. Which of the following is the most likely cause of the 'Disk quota exceeded' error?

Accepted Answer

An XFS project quota is configured on the /data directory, limiting the space used by the database files.. Option B is correct because XFS project quotas can limit the total space used by a directory tree, regardless of the user or group that owns the files. Even though no user or group quotas are set, a project quota on /data restricts the database files, causing 'Disk quota exceeded' errors despite 40% free space on the filesystem.

Answer

The logical volume is thin provisioned and the data pool is full.

Answer

SELinux is blocking the database writes due to a denial.

Answer

The filesystem has run out of inodes.

Question 15

A system administrator needs to create a file system on /dev/sdb1 with a size of 10 GB and mount it persistently at /data. The file system should support extended attributes and be suitable for large files. Which command sequence achieves this?

Accepted Answer

mkfs.xfs /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data xfs defaults 0 0' >> /etc/fstab. Option B is correct because it uses mkfs.xfs to create an XFS file system on /dev/sdb1, which supports extended attributes and is optimized for large files. It then creates the mount point /data, mounts the file system, and adds an entry to /etc/fstab for persistent mounting with the correct device, mount point, and file system type.

Answer

mkfs.xfs /dev/sda1 && mkdir /data && echo '/dev/sda1 /data xfs defaults 0 0' >> /etc/fstab

Answer

mkfs.ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab

Answer

mkswap /dev/sdb1 && mkdir /data && swapon /dev/sdb1 && echo '/dev/sdb1 /data swap defaults 0 0' >> /etc/fstab

Question 16

Which TWO commands are valid for resizing an XFS file system? (Choose exactly two.)

Accepted Answer

xfs_growfs /mnt. Option B is correct because `xfs_growfs` is the dedicated command for resizing (growing) an XFS file system while it is mounted. It expands the file system to fill the available space in the underlying device or logical volume, making it the primary tool for XFS resizing operations.

Answer

xfs_admin -L /mnt

Answer

resize2fs /dev/sda1

Answer

xfs_repair /dev/sda1

Question 17

Refer to the exhibit. The administrator wants to create a single file system that spans the entire 20 GB disk /dev/sdb. All data on the disk can be discarded. Which steps are required to create an XFS file system on the whole disk?

Accepted Answer

Use fdisk to delete all partitions, create a new partition spanning the whole disk, then run mkfs.xfs on the new partition.. Option D is correct because creating a file system directly on a whole block device (like /dev/sdb) without a partition table is not recommended and may cause issues with system tools and boot loaders. The proper procedure is to first create a single partition spanning the entire disk using fdisk (or parted), then format that partition (e.g., /dev/sdb1) with mkfs.xfs. This ensures a valid partition table is present, which is expected by most Linux utilities and the kernel.

Answer

Run mkfs.xfs /dev/sdb directly; it will overwrite the partition table and create a file system.

Answer

Use pvcreate /dev/sdb, then vgcreate, lvcreate, and format the logical volume with mkfs.xfs.

Answer

Run mkfs.xfs -f /dev/sdb; it will force creation of XFS on the whole disk without partition table.

Question 18

Put the steps to configure a cron job that runs a script every day at 2:30 AM in the correct order.

Question 19

Match each command to its function in managing storage.

Question 20

A junior administrator needs to create a new Ext4 file system on the device /dev/sdb1. Which command should be used?

Accepted Answer

mkfs.ext4 /dev/sdb1. The `mkfs.ext4` command is the standard utility for creating an ext4 filesystem on a block device. It formats the partition with the ext4 journaling filesystem, writing the superblock, inode table, and journal metadata. Option D is correct because it directly invokes the mke2fs program with the ext4 filesystem type.

Answer

fdisk /dev/sdb1

Answer

parted /dev/sdb1

Answer

tune2fs /dev/sdb1

Answer

fsck /dev/sdb1