Devices, Filesystems and FHS

You manage a CentOS 7 server that runs a critical application storing data on an XFS filesystem mounted at /data. The server experiences an unexpected power outage. After rebooting, the application fails to start, and you suspect filesystem corruption. You boot into single-user mode and attempt to mount /data, but the mount fails with an error: 'mount: /dev/sdb1: can't read superblock'. You run 'xfs_repair -n /dev/sdb1' and it reports the log is dirty and must be replayed or the filesystem repaired with the -L option (force log zeroing). You want to recover the filesystem with minimal data loss. Which action should you take?

A Linux system has multiple disk partitions. The administrator wants to view the UUID of a specific partition for use in /etc/fstab. Which command will display the UUID?

A system is experiencing frequent crashes. Investigation shows that the root filesystem is mounted with 'errors=remount-ro'. The admin wants to prevent data loss by mounting with 'errors=panic' in /etc/fstab. Which change is correct?

Refer to the exhibit. Which filesystem will be checked last during system boot by fsck?

Refer to the exhibit. A user tries to execute a script on a mounted filesystem but gets a permission denied error. The script has execute permissions. What is the most likely cause?

Refer to the exhibit. An administrator wants to add a new partition that uses the remaining space on /dev/sda (total 40GB). What is the next free sector for the start of the new partition?

Match each networking tool to its primary use.

A Linux administrator is troubleshooting a server that fails to boot with the error 'Give root password for maintenance (or press Control-D to continue)'. The root filesystem is on /dev/sda2, formatted as ext4. The administrator suspects a filesystem inconsistency. The server is in a remote data center and the administrator has console access via IPMI. Which of the following is the safest procedure to repair the filesystem?

A system fails to mount an XFS filesystem with the entry in /etc/fstab. The entry looks correct. Which fstab field might be missing or incorrect?

Which FHS directory contains essential binaries needed for booting and repairing the system, even before /usr is mounted?

Refer to the exhibit. An admin attempts to execute a shell script located in /tmp but gets 'Permission denied'. Which mount option is most likely causing this?

Based on the lsblk output, which of the following is true?

Which THREE of the following commands can be used to display information about block devices?

Which TWO utilities can be used to check and repair an XFS filesystem?

Refer to the exhibit. An administrator notices that /proc is mounted with 'noexec'. What is the impact of this mount option?

Which directory in the Filesystem Hierarchy Standard (FHS) contains essential user command binaries that are needed in single-user mode?

A database server with high I/O requirements needs a filesystem layout optimized for performance. The server has four identical 500GB SSDs. Which design best balances performance and reliability, considering the need to separate transaction logs from data files?

You are a system administrator at a hosting company. A customer reports that their website hosted on a shared LAMP server is returning error 500. The server runs Ubuntu 22.04 with Apache, MySQL, and PHP. You log in and find that the /var partition (on /dev/sda3, ext4) is almost full. You identify that the MySQL database directory /var/lib/mysql contains several large binary logs that are no longer needed. You delete the binary logs using 'rm -f /var/lib/mysql/mysql-bin.*'. However, the available space does not increase. You also notice that an inode leak is suspected. You check inode usage with 'df -i' and see that the partition has plenty of free inodes. You then check with 'lsof | grep deleted' and see several entries for mysqld holding deleted files. What is the correct procedure to free the space?

A technician runs 'blkid' and sees output like '/dev/sda2: UUID="abc-def-ghi" TYPE="ext4"'. Which command can mount this partition using its UUID?

A user complains that a filesystem is reporting 'Disk quota exceeded' even though the user has not stored any new files recently. What could be the cause?

A system is running out of disk space on /var. The administrator finds that /var/log/syslog is 4GB. Which of the following is the best course of action to prevent future issues while keeping recent logs?

A Linux system fails to boot with the error 'Kernel panic: VFS: Unable to mount root fs on unknown-block(0,0)'. After investigation, the administrator suspects that the root filesystem device is not being detected. Which of the following is the most likely cause?

A system administrator notices that the /tmp directory is filling up quickly, causing applications to fail. The administrator wants to ensure that files in /tmp are automatically cleaned after a certain period. Which of the following is the best approach without installing additional software?

Refer to the exhibit. The system administrator notices the /var/log partition is nearly full. The syslog file is 2GB. Which command will safely reduce the size of this log file without stopping the logging daemon?

During boot, a Linux system displays 'Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. Which of the following is the most likely cause?

Which directory under the root filesystem is defined by FHS as containing variable data that may change in size, such as logs and spools?

An administrator is configuring a new server with two SATA disks. The first disk (/dev/sda) holds the root filesystem. The second disk (/dev/sdb) is intended to provide additional storage for user home directories. The administrator partitions /dev/sdb using 'fdisk' to create a single partition /dev/sdb1, formats it with 'mkfs.ext4' and adds the following line to /etc/fstab: '/dev/sdb1 /home ext4 defaults 0 2'. After rebooting, the /home directory is empty and the command 'df -h' does not show /dev/sdb1. However, running 'mount /dev/sdb1 /home' manually works perfectly. The disk is not listed in 'cat /proc/mounts' before the manual mount. What is the most likely cause of this issue?

Which THREE directories under the root filesystem are typically used for variable data that changes frequently during system operation, according to FHS?

According to the Filesystem Hierarchy Standard (FHS), which TWO directories are intended for variable data that persists across system reboots? (Choose two.)

According to the Filesystem Hierarchy Standard (FHS), which directory contains essential system binaries required during boot?

Refer to the exhibit. The root filesystem is at 95% capacity. Which option will free space on the root filesystem?

A system administrator notices that a server with an ext4 filesystem fails to boot after editing /etc/fstab. The error message indicates that the root filesystem cannot be mounted. Which of the following is the most likely cause?

An admin needs to create a new filesystem on /dev/sdc1 with a 256-byte inode size and a 1:512 block to inode ratio for a mail server expected to store millions of small files. Which mkfs command best meets these requirements?

A Linux system has a 500GB SSD. The administrator wants to partition it to support a web server with the following requirements: root (/) 20GB, swap 4GB, /var 50GB, /home 100GB, and the remaining for /srv. Which partitioning strategy is best practice according to the FHS and performance considerations?

Which TWO of the following are true about the /proc filesystem?

A system administrator needs to check if a filesystem has any errors without actually performing a repair. Which command should be used?

A medium-sized company runs a web server on Linux with two 1TB disks in a software RAID1 (mdadm) configuration for the root filesystem and /var. Recently, the /var partition is reporting low disk space. The administrator discovers that old log files are consuming space but should be rotated. However, the logrotate service is not running. After starting logrotate, it fails to rotate some logs because of missing directories. Additionally, the administrator wants to add a third disk (500GB SSD) for additional storage and mount it under /srv/webdata. The disk is new and not partitioned. The server uses systemd and the current /etc/fstab uses UUIDs. What is the correct sequence of steps to add the new disk and ensure it is mounted automatically at boot?

Which of the following directories is NOT defined in the Filesystem Hierarchy Standard (FHS)?

Refer to the exhibit. A user tries to write to /mnt/usb/myfile.txt as a non-root user and receives a permission denied error. What is the most likely reason?

An administrator needs to identify the device file for the first SATA SSD in a server. Which device file should they use?

Which THREE conditions will cause the fsck command to automatically run on the root filesystem during boot? (Choose three.)

A server has a partition /dev/sda2 that is almost full. The admin suspects a large file has been deleted but is still held open by a process. Which command can identify such a file?

A Linux system has a software RAID1 array /dev/md0 consisting of /dev/sda1 and /dev/sdb1. After replacing a failed disk, the administrator runs 'mdadm --manage /dev/md0 --add /dev/sdc1', but the array remains degraded. Which command should be used to check the status of the array?

You are a junior system administrator tasked with adding a new 500GB HDD to a Debian 11 server that will be used for backup storage. The server currently has a 120GB SSD with two partitions: sda1 (boot) and sda2 (root). You have physically installed the HDD and it is recognized as /dev/sdb. You need to partition the disk with a single partition covering the entire disk, format it as ext4, and ensure it is automatically mounted at /backup at boot time. Which sequence of commands should you execute to accomplish this?

The /proc filesystem is described as a virtual filesystem. Which statement best describes its purpose?

Which THREE commands can be used to display the UUID of a filesystem on a Linux system without superuser privileges? (Choose three.)

Which TWO options in /etc/fstab affect whether a filesystem is mounted at boot? (Choose two.)

A disk is partitioned with GPT. The administrator wants to see the partition type GUIDs and partition UUIDs. Which command is most appropriate?

A system administrator wants to ensure that the filesystem on /dev/sdb1 is checked for errors every 30 mounts. Which command accomplishes this?

Which TWO of the following commands can be used to create a new filesystem on a partition?

A Linux system has two SATA disks: /dev/sda (250GB) and /dev/sdb (500GB). The administrator wants to create a logical volume group named 'vgdata' using partitions on both disks, then create a 600GB logical volume named 'lvdata' for a database. Which sequence of commands should be used?

Refer to the exhibit. An administrator attempts to remount /mnt as read-only but receives the error shown. What is the most likely cause?

You are a Linux administrator for a large e-commerce company. The company's application server runs Ubuntu 22.04 and uses a Btrfs filesystem for the /srv/app partition to take advantage of snapshots and compression. During a routine maintenance window, you create a snapshot of the /srv/app subvolume using 'btrfs subvolume snapshot /srv/app /srv/app_snapshot'. Later, you need to roll back to the snapshot because of a failed application update. You attempt to delete the original subvolume with 'btrfs subvolume delete /srv/app', but the command fails with the error: 'ERROR: cannot delete '/srv/app': Device or resource busy'. You check that no processes are using the directory with lsof, and it shows no open files. The /srv/app subvolume is the default subvolume and is mounted via fstab with the option 'subvol=/' (the root of the Btrfs filesystem). What is the most likely reason for the deletion failure, and how should you proceed?

A Linux technician receives a report that a USB flash drive inserted into a system is not automatically detected. Which command should the technician use to verify if the device is recognized by the kernel?

Which TWO commands can be used to display information about block devices such as disks and partitions? (Choose exactly two.)

Refer to the exhibit. The system administrator wants to ensure the /data filesystem is mounted only if it is available at boot time, and if not, the system should continue to boot without error. Which change should be made to the /etc/fstab entry for /data?

According to FHS, which directory should NOT be mounted on a networked filesystem (e.g., NFS) because it contains host-specific configuration files?

An ext4 filesystem is experiencing performance degradation due to very frequent small writes. Which tune2fs option can help by reserving a percentage of blocks for the root user to prevent fragmentation?

Refer to the exhibit. The 'mount -a' command fails for the NFS mount. What is the most likely cause?

You are the system administrator for a small business running a Red Hat Enterprise Linux 8 server that hosts a MySQL database and a web server. The server has two physical disks: a 240GB SSD (sda) with partitions sda1 (boot), sda2 (root), sda3 (swap), and a 1TB HDD (sdb) with a single partition sdb1 mounted at /var/lib/mysql. The server has been running for months without issues. However, this morning you receive alerts that the MySQL database is not accepting new connections. You log in and find that the /var filesystem is 100% full. You check the disk usage and see that /var/lib/mysql uses 90% of the space, but there are also large log files in /var/log/httpd. To free up space immediately and restore database service while planning a permanent solution, you decide to compress old log files and move some database archives to a backup server. After compressing several log files with gzip, the available space increases by only a few MB. You then delete some old database backups from /var/lib/mysql/backup, but the space usage shown by df remains unchanged. What is the most likely cause of this behavior?

An administrator runs `fsck /dev/sdb1` on an ext4 filesystem that is currently mounted. What is the likely outcome?

An application assumes its data is stored in /opt/app/data, but the /opt filesystem is running out of space. The administrator moves the data to /var/app/data. Which method will allow the application to continue accessing the data at /opt/app/data without modifying the application's configuration?

Which TWO of the following are valid mount options for the ext4 filesystem?

After plugging in a USB storage device, the system does not automatically mount it. The 'lsusb' command shows the device. What is the first command to check if the kernel detected the block device?

Refer to the exhibit. A user 'user1' tries to run the setuid binary 'myapp' but gets permission denied. What is the most likely reason?

A company is setting up a database server that requires high reliability and support for snapshots. The storage will be on a single large disk. Which filesystem is best suited for this requirement?

Which TWO commands can be used to create an ext4 filesystem on a partition?

Which command creates an ext4 filesystem on /dev/sdb1 without interactive prompts?

Which THREE directories are required by the Filesystem Hierarchy Standard (FHS) to exist on the root filesystem? (Choose three.)

Refer to the exhibit. After adding a new disk to the system, the device /dev/sdb appears. However, the administrator cannot create partitions on /dev/sdb using fdisk. What is the most likely reason?

Refer to the exhibit. The root filesystem is nearly full. The administrator needs to increase its size. Which steps should be performed?

Which THREE of the following filesystem types are journaling filesystems? (Choose exactly three.)

Refer to the exhibit. The system logs show the above messages. What is the most likely cause and the correct first action?

Refer to the exhibit. On boot, which filesystem will be checked first by fsck?

After modifying /etc/fstab, an administrator wants to test if the new mount points can be mounted without rebooting. Which command should be used?

Which TWO commands can be used to display the UUID of a filesystem? (Choose two.)

Refer to the exhibit. The administrator wants to mount /dev/sdb1 persistently using its UUID. Which line should be added to /etc/fstab?

An admin runs 'lsblk' and sees that /dev/nvme0n1p1 is listed with size 512M and mounted at /boot/efi. What is the most likely filesystem type?

After running 'df -h', the administrator sees that /dev/sda1 is 100% used. 'du -sh /mountpoint' shows only 50% used. What is the most likely cause?

Which THREE of the following directories are defined in the Filesystem Hierarchy Standard (FHS) and are expected to exist on a typical Linux system?

Arrange the steps to create a LVM logical volume and mount it.

Refer to the exhibit. How many physical disks are present in the system?

Refer to the exhibit. Based on the mount options shown, which filesystem is most likely to store filenames with mixed case and support long filenames?

Based on the /etc/fstab entry, which filesystem will be checked by fsck at boot time?

Which THREE of the following directories are part of the FHS and must be present on a standard Linux system? (Choose three.)

An administrator needs to mount a USB drive with the ext4 filesystem automatically at boot. The drive has a filesystem label 'DATA'. Which entry in /etc/fstab will mount it at /mnt/data with noatime and default mount options?

Refer to the exhibit. The system administrator sees that /var/log is 93% full and the syslog file is nearly 2 GB. What is the most appropriate immediate action to free up disk space without losing any critical log data?

An administrator needs to mount an ISO file located at /tmp/data.iso to /mnt/iso for read-only access. Which command should be used?

A company runs a web server on Linux with two hard disks: /dev/sda (500GB) and /dev/sdb (500GB). The root filesystem is on /dev/sda1, and /var is on /dev/sda2. The administrator wants to add a new disk /dev/sdc (500GB) to be used as additional storage for /var/www/html. The new disk should be configured as an LVM physical volume and added to an existing volume group named 'vg_web'. The volume group currently has 200GB free space from /dev/sdb1. The administrator intends to extend the logical volume 'lv_web' mounted at /var/www/html by 300GB. Which of the following is the correct sequence of commands to achieve this without data loss?

An administrator needs to mount an ISO image file /tmp/image.iso to the directory /mnt/iso. Which command should be used?

Which TWO statements about udev rules are correct? (Choose two.)

Which of the following commands displays the amount of free disk space on all mounted filesystems in a human-readable format?

Match each file system type to its typical description.

An administrator plans to back up the /home filesystem using dump. Which option to dump is required to perform a full backup?

A technician is repairing a system and needs to mount the root filesystem from a different disk to /mnt/sysroot. The partition is /dev/sda2 with an ext4 filesystem. Which command should be used?

A system administrator wants to mount a USB flash drive formatted with the ext4 filesystem. The device is detected as /dev/sdc1. Which command should be used to mount the device to /mnt/usb?

A user reports that a USB drive (device /dev/sdc1) is not automatically mounted at boot. The output of 'blkid' and the relevant line in /etc/fstab are shown in the exhibit. What is the most likely cause of the failure?

A system administrator wants to install custom scripts that should be available to all users. The scripts are not part of any package and should be placed under the Filesystem Hierarchy Standard (FHS). Which directory is most appropriate?

Refer to the exhibit. An administrator wants to mount /dev/sda4 persistently by its UUID. Which line should be added to /etc/fstab?

A company wants to migrate a database server from ext4 to XFS to support larger files and better scalability. The current data resides on a single partition /dev/sda1 mounted at /data. Which procedure ensures a successful migration with minimal downtime?

An administrator needs to create a new ext4 filesystem on /dev/sdb1 and wants to reserve 2% of the blocks for the root user. Which command should be used?

After a system crash, the root filesystem (ext4) is mounted read-only and the administrator needs to perform an interactive check. Which command should be used?

A Linux system fails to boot after an admin added an entry in /etc/fstab to mount an NFS share. The error message indicates 'mount: can't find /mnt/nfs in /etc/fstab'. Which is the most likely cause?

You are a systems administrator for a medium-sized company that runs a web server on a Linux host. The server has two physical disks: /dev/sda (250 GB) and /dev/sdb (500 GB). The root filesystem is on /dev/sda2, and /var is on /dev/sda3 (50 GB). The web application stores user-uploaded files in /var/www/uploads, which is part of the /var filesystem. Recently, /var has been running out of space because uploads have grown to 40 GB. You have added /dev/sdb1 (500 GB) and created an ext4 filesystem on it. You need to make the space available for uploads without disrupting the current file paths. The server must remain online during the process. Which of the following actions should you take?

Refer to the exhibit. How much unpartitioned space is available on /dev/sda?

A system administrator needs to locate the largest directories under /var to free up disk space. Which command is most appropriate?

Order the steps to create and apply a file system permission using ACLs.

A system reports 'No space left on device' but 'df -h' shows only 60% usage. Which command would help identify the cause?

A system administrator is troubleshooting a server where the /var partition is full, causing services to fail. The administrator deletes old log files in /var/log, but the available space does not increase. Which step should be taken next?

An administrator notices that a large file on an ext4 filesystem is taking up more disk space than expected based on its size. Which command would show the actual disk usage (block allocation) of the file?