LPIC-1 Devices, Filesystems and FHS Practice Test 9 — 15 Questions

Question 1

A Linux administrator needs to create an ext4 filesystem on the second partition of the third SCSI disk, /dev/sdc2. After running mkfs.ext4 /dev/sdc2, the command completes successfully. Which additional step is required before the filesystem can be mounted and used?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Create a mount point and mount the filesystem.. Creating a filesystem with mkfs.ext4 only writes the filesystem metadata and structures onto the partition. To access the filesystem, it must be mounted to a directory in the existing directory tree. The administrator must create a mount point and use the mount command. Without mounting, the filesystem remains inaccessible to users and applications.

Answer

Run e2fsck /dev/sdc2 to initialize the journal.

Answer

Add an entry to /etc/fstab to make the filesystem usable immediately.

Answer

Run partprobe /dev/sdc to update the kernel partition table.

Question 2

A Linux administrator is preparing a new server and needs to create an ext4 filesystem on the /dev/sdb1 partition. Which command should be used?

Accepted Answer

mkfs -t ext4 /dev/sdb1. The mkfs command is the standard utility for creating filesystems. Using mkfs -t ext4 /dev/sdb1 explicitly specifies the ext4 filesystem type. This invokes the mkfs.ext4 program, which writes the ext4 superblock, inode tables, and journal to the partition. Other commands like fsck and tune2fs are for checking or modifying existing filesystems, not for creation.

Answer

fsck.ext4 /dev/sdb1

Answer

tune2fs -t ext4 /dev/sdb1

Answer

mke2fs -j /dev/sdb1

Question 3

A technician needs to inspect the filesystem type, UUID, and filesystem label of the partition /dev/sdb1 without mounting it. Which command provides all of this information in a single invocation?

Accepted Answer

blkid /dev/sdb1. blkid reads on-disk superblock metadata and reports UUID, TYPE, and LABEL for a block device without requiring a mount. That single invocation answers all three questions the technician has. fdisk shows partition-table data, lsblk -f is less reliable when given a single partition argument, and tune2fs works only on ext-family filesystems, so each of those alternatives leaves part of the requirement unmet.

Answer

lsblk -f /dev/sdb1

Answer

tune2fs -l /dev/sdb1

Answer

fdisk -l /dev/sdb1

Question 4

A junior administrator needs to create a new ext4 filesystem on the partition /dev/sdb2. The partition already exists but has never been formatted. Which command should the administrator run to create the filesystem?

Accepted Answer

mkfs.ext4 /dev/sdb2. Creating a filesystem requires a mkfs-family tool, and the ext4-specific front end is mkfs.ext4. Because the partition exists but is blank, no partitioning step is needed and no mount or repair step applies. The command writes the on-disk structures that make /dev/sdb2 mountable as ext4.

Answer

fsck.ext4 /dev/sdb2

Answer

mount -t ext4 /dev/sdb2 /mnt

Answer

fdisk /dev/sdb2

Question 5

A junior administrator accidentally deleted a large log file that is still being written to by a running process. The file no longer appears in directory listings, but `df -h` shows the filesystem is still nearly full. Which command will reclaim the space without interrupting the running process?

Accepted Answer

truncate -s 0 /proc//fd/ using the file descriptor path. An unlinked file that remains open keeps its inode and data blocks allocated until the last descriptor closes. Truncating the file through its /proc//fd/ descriptor zeroes the content and frees the blocks while the process continues running, satisfying the requirement of no interruption. Diagnostics like lsof help locate the descriptor, but the reclamation itself must act on the open file.

Answer

Run sync to flush dirty pages and free the deleted file's blocks

Answer

lsof | grep deleted, then kill the process holding the file

Answer

Run fsck on the filesystem to release orphaned inodes

Question 6

A server has a dedicated disk /dev/sdc that will store application logs. The administrator wants the filesystem to be checked automatically only after 30 mounts or 60 days, whichever comes first, and wants to reduce the reserved block percentage to 1 percent. Which single command accomplishes both changes on the existing ext4 filesystem?

Accepted Answer

tune2fs -c 30 -i 60d -m 1 /dev/sdc. Adjusting existing ext filesystem behavior is the job of tune2fs, which writes superblock fields such as maximum mount count, check interval, and reserved block percentage. Formatting tools would destroy data, and checking or reporting tools cannot alter policy. The single command combining -c, -i, and -m meets both requirements.

Answer

dumpe2fs -c 30 -i 60d -m 1 /dev/sdc

Answer

e2fsck -c 30 -i 60d -m 1 /dev/sdc

Answer

mkfs.ext4 -c 30 -i 60d -m 1 /dev/sdc

Question 7

A Linux administrator runs df -h and sees that the /var filesystem is 100% full. The administrator deletes several large log files, but df still shows 100% usage. Which command should the administrator use to identify processes that are holding deleted files open?

Accepted Answer

lsof +L1. When a file is deleted but still open by a process, the directory entry is removed, but the inode and data blocks remain allocated until the process closes the file. df reflects the actual blocks allocated, while du only sees directory entries. lsof +L1 lists open files with link count less than 1, identifying deleted files still in use. Restarting the holding process releases the space.

Answer

fdisk -l /dev/sda

Answer

fsck /dev/sda1

Answer

du -sh /var

Question 8

A user reports that a USB flash drive plugged into a Linux workstation is not automatically mounted. The administrator runs 'lsblk' and sees the device as /dev/sdb1 with no mountpoint. Which command should the administrator use to manually mount the filesystem on /dev/sdb1 to the /mnt/usb directory?

Accepted Answer

mount /dev/sdb1 /mnt/usb. The correct command is 'mount /dev/sdb1 /mnt/usb'. This uses the standard syntax of device followed by mount point. The system will auto-detect the filesystem type. Other options either reverse the arguments, add unnecessary options, or use loop mounting which is not applicable.

Answer

mount -t auto /dev/sdb1 /mnt/usb

Answer

mount /mnt/usb /dev/sdb1

Answer

mount -o loop /dev/sdb1 /mnt/usb

Question 9

An administrator must configure persistent mounts for two filesystems on a database server. One is an ext4 volume that should be mounted at boot without failing the whole boot process if it is unavailable. The other is a swap partition that must be activated at boot. Which TWO entries belong in /etc/fstab to meet these requirements? (Choose two.)

Accepted Answer

UUID=5678-efgh /data ext4 defaults,nofail 0 2. Persistent mounts are declared in /etc/fstab using the device, mount point, filesystem type, options, dump, and fsck pass fields. The ext4 volume needs nofail so an unavailable device does not halt boot, while swap uses the mount point none, type swap, and option sw. The two entries matching those patterns are correct.

Answer

UUID=1234-abcd /data ext4 defaults,noauto 0 2

Answer

UUID=90ab-cdef /swap swap defaults 0 2

Answer

UUID=5678-efgh /data ext4 defaults 1 1

Question 10

A user reports that they cannot create new files in their home directory even though the filesystem shows free space. Running df -h shows the filesystem at 100 percent inode usage. Which action most directly resolves the immediate problem?

Accepted Answer

Delete unneeded files that consume many inodes, such as old session files or cached mail, to free inode entries.. When df -h reports 100 percent inode usage, the filesystem has no free inode entries even though data blocks may remain. Deleting many small files, such as session or cache files, releases inodes and restores file creation. Expanding the filesystem, remounting with noatime, or adjusting the check interval do not increase available inodes and therefore do not fix the immediate issue.

Answer

Run resize2fs to expand the filesystem onto additional space.

Answer

Remount the filesystem with the noatime option to stop inode updates.

Answer

Increase the inode count by running tune2fs -i 0 on the mounted filesystem.

Question 11

A Linux administrator needs to create a new ext4 filesystem on a logical volume /dev/vg0/lv_data and mount it persistently at /data. Which TWO of the following steps are required to accomplish this? (Choose two.)

Accepted Answer

Add an entry for /dev/vg0/lv_data in /etc/fstab. To create and persistently mount a new ext4 filesystem on an existing logical volume, the administrator must first create the filesystem with mkfs.ext4, then add an entry to /etc/fstab to ensure it mounts at boot. Other commands like pvcreate, vgcreate, and mount -a are either incorrect or not strictly required for this task.

Answer

Run pvcreate /dev/vg0/lv_data

Answer

Run mount -a to mount all filesystems

Answer

Run vgcreate vg0 /dev/vg0/lv_data

Question 12

A technician is troubleshooting a server whose /var partition is reported as full by applications, but df -h shows the filesystem at only 40 percent usage. The technician suspects deleted files are still held open by running processes. Which command best identifies the process holding a deleted file open on that filesystem?

Accepted Answer

lsof +L1. When a file is unlinked while a process still holds it open, the blocks remain allocated but the name disappears from the directory tree, so df shows usage that du cannot account for. lsof with the +L1 filter enumerates files whose link count has dropped below one, exposing the process responsible and allowing the administrator to restart it and reclaim space.

Answer

fuser -m /var

Answer

df -i /var

Answer

du -sh /var

Question 13

A server has an LVM logical volume mounted at /data. The administrator needs to add a new physical disk to the volume group and then extend both the logical volume and the filesystem online, without unmounting. Which sequence of commands achieves this?

Accepted Answer

pvcreate /dev/sdc1; vgextend data_vg /dev/sdc1; lvextend -r -L +50G /data. Extending LVM storage online requires initializing the new device with pvcreate, adding it to the existing group with vgextend, and growing the logical volume with lvextend while using -r so the filesystem is expanded in the same step. Reversing the first two commands, creating a new volume group, or omitting the filesystem resize all leave the task incomplete or failing outright.

Answer

vgextend data_vg /dev/sdc1; pvcreate /dev/sdc1; lvextend -L +50G /data; resize2fs /data

Answer

pvcreate /dev/sdc1; vgextend data_vg /dev/sdc1; lvresize -L +50G /data; mount -o remount /data

Answer

pvcreate /dev/sdc1; vgcreate data_vg /dev/sdc1; lvextend -r -L +50G /data

Question 14

An administrator needs to gather detailed information about the partition table and filesystem geometry of /dev/sda before migrating data. Which TWO commands will display the partition layout of the disk? (Choose two.)

Accepted Answer

fdisk -l /dev/sda. Both fdisk -l and parted print read and display the on-disk partition table, enumerating partitions with their start and end positions and the table type. The other tools focus on filesystem identity or capacity rather than partitioning: blkid and lsblk -f describe what filesystems exist, and df reports mount usage. For migration planning that requires partition geometry, the partition-table readers are the correct choices.

Answer

lsblk -f /dev/sda

Answer

blkid /dev/sda

Answer

df -h /dev/sda

Question 15

An administrator is preparing a new USB drive for use as a portable ext4 data disk. After writing the partition table, the administrator wants to confirm the partition layout and the filesystem type currently on the device before formatting. Which command displays both the partition table and the detected filesystem types for /dev/sdd?

Accepted Answer

lsblk -f /dev/sdd. Verifying a device before formatting requires both the partition layout and any existing filesystem signatures. lsblk with the -f option merges block device topology from sysfs with filesystem metadata detected by libblkid, showing each partition's type, label, UUID, and mount point in a single tree view, which covers both needs at once.

Answer

partprobe /dev/sdd

Answer

fdisk -l /dev/sdd

Answer

blkid /dev/sdd