EX200 Create and configure file systems — Timed 25 Questions

Question 1

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?

25 minute time limit — choose an answer to begin.

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, resulting in the observed error. Red Hat exams often test this nuance, where SELinux can cause a 'does not exist' error even when the directory is present, leading candidates to overlook SELinux as the root cause.

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 2

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. 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 3

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

Accepted Answer

noexec. For an ext4 filesystem, all of the following are valid mount options that can appear in /etc/fstab: noexec, relatime, noatime, suid, and nodev. The options suid and nosuid are a pair, as are dev and nodev, exec and noexec. Thus the statement that only three are valid is false.

Answer

suid

Answer

nodev

Question 4

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

Accepted Answer

The filesystem was not resized after extending the LV.. 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 5

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 6

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

Run mkfs.xfs -f /dev/sdb; it will force creation of XFS on the whole disk without partition table.. An XFS file system can be created directly on a whole block device (e.g., mkfs.xfs -f /dev/sdb). This is a valid method and does not require a partition table. Creating a partition first (option D) is an acceptable alternative, but not the only required set of steps. The original explanation incorrectly states that a partition is required.

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.

Question 7

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

Accepted Answer

Edit the crontab file with 'crontab -e', add the line '30 2 * * * /path/to/script', then save and exit.. The standard method is to use `crontab -e` to edit the current crontab and add the line `30 2 * * * /path/to/script`. However, an equally valid method is to create a file containing that line and run `crontab <filename>` to install it as the crontab. Both methods are accepted on Red Hat systems. Therefore both A and B are correct.

Answer

Save and exit the crontab file first, then edit it again to add the line '30 2 * * * /path/to/script'.

Answer

Exit the crontab editor immediately, then edit the file again with 'crontab -e' and add the line '30 2 * * * /path/to/script'.

Question 8

To enable per-user quotas on an XFS file system, which mount option should be used?

Accepted Answer

uquota. On XFS file systems, both `uquota` and `usrquota` are valid mount options to enable per-user quotas—`uquota` is the shorthand, `usrquota` is the long form. However, the Red Hat EX200 exam specifically expects `uquota` as the correct answer, as it is the XFS‑specific notation, and candidates are tested on this exact syntax. While `usrquota` works on XFS, only `uquota` is considered correct for the exam.

Answer

quota

Answer

usrquota

Answer

user_quota

Question 9

Which TWO of the following are required to create an XFS file system on LVM?

Accepted Answer

Run mkfs.xfs on the LV. To create an XFS file system on LVM, you must first have a logical volume to format, so option E (Create a logical volume) is correct because mkfs.xfs operates on a block device such as /dev/vg/lv. Option D (Run mkfs.xfs on the LV) is correct because mkfs.xfs is the actual command that writes the XFS file system metadata and structure onto the logical volume. Options A and B are not among the two required answers here because, while a volume group and physical volume are part of the broader LVM stack, the question specifically asks for the two steps needed to create the XFS file system on an existing LV. Option C is incorrect because xfs_admin is used to change parameters of an existing XFS file system, not to create one.

Answer

Create a volume group

Answer

Create a physical volume

Answer

Run xfs_admin on the LV

Question 10

The administrator wants to remount /mnt/data with the noexec option. Which command is correct?

Accepted Answer

mount -o remount,noexec /mnt/data. The `mount -o remount,noexec /mnt/data` command changes the mount options of an already mounted filesystem without needing to unmount it first. The `remount` option applies the new `noexec` flag to the existing mount point, preventing execution of binaries on that filesystem. This is the standard and safest way to modify mount options on a live system.

Answer

Edit /etc/fstab to add noexec and reboot

Answer

mount -o remount,noexec /dev/sdb1 /mnt/data

Answer

umount /mnt/data && mount -o noexec /dev/sdb1 /mnt/data

Question 11

A system administrator at a company is configuring a new storage array for a file server. The server uses LVM on top of a hardware RAID5 array. The administrator has created a volume group "vg_data" and a logical volume "lv_docs" intended for an XFS filesystem. After formatting with mkfs.xfs and mounting to /docs, the system works. However, after a reboot, the mount point is empty and the logical volume is not mounted. The administrator checks /etc/fstab and finds an entry using the device path /dev/vg_data/lv_docs. What is the most likely cause?

Accepted Answer

The volume group is not activated during boot because the LVM service is not enabled. LVM volume groups are not automatically activated during boot unless the lvm2-lvmetad service (or equivalent LVM service) is enabled. Without this service, the system does not scan for and activate volume groups, so logical volumes like /dev/vg_data/lv_docs are not available for mounting. The /etc/fstab entry using the device path fails silently, leaving /docs empty.

Answer

The mount point /docs was deleted during reboot

Answer

The XFS filesystem was corrupted during reboot

Answer

The logical volume name is misspelled in /etc/fstab

Question 12

Refer to the exhibit. A storage administrator needs to create a new filesystem of size 1.5 GiB on the available free space in volume group vg_data. Which command should be used?

Accepted Answer

lvcreate -L 1.5G -n lv_new vg_data. The volume group vg_data has 1.99 GiB free space. To create a 1.5 GiB logical volume, use lvcreate with -L 1.5G -n lv_new vg_data. The -L option specifies size, -n specifies name.

Answer

lvcreate -l 1.5G -n lv_new vg_data

Answer

lvcreate --size 1.5G --name lv_new vg_data

Answer

lvcreate -L 1500M -n lv_new vg_data

Question 13

Refer to the exhibit. A client at 10.0.0.5 tries to mount /export/restricted but receives 'Permission denied'. What is the issue?

Accepted Answer

The client IP 10.0.0.5 is not in the allowed subnet 192.168.1.0/24. The client at 10.0.0.5 is attempting to mount /export/restricted. The /etc/exports file restricts access to 192.168.1.0/24. Since 10.0.0.5 is not included in that subnet, the NFS server denies the mount with 'Permission denied'. There is no evidence that the entry is missing or that a re-export is needed; the issue is network access control.

Answer

The client's IP is in the allowed subnet but the export entry for /export/restricted is missing from /etc/exports after a change and not re-exported

Answer

The export uses root_squash which maps root to nobody, causing permission issues

Answer

The export /export/restricted has ro (read-only) and the client might be trying to write

Question 14

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. 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 15

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 16

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.. 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 17

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

The filesystem is XFS, and fsck does not repair XFS.. If fsck reports 'clean', it means no errors were found in the filesystem's journal, so option D is incorrect. Option C is correct because XFS filesystems cannot be repaired by fsck; they require xfs_repair. Running fsck on an XFS filesystem simply reports the clean flag without performing a real check, leaving the kernel to enforce read-only status if any issues persist.

Answer

fsck cannot fix errors on ext4 filesystems.

Answer

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

Answer

fsck detected errors but did not fix them automatically.

Question 18

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'. 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 19

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

Accepted Answer

mkfs.xfs -L data /dev/nvme0n1p1. 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 20

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