LPIC-2 Practice Test 27 — 15 Questions

Question 1

A junior administrator needs to determine which kernel is currently running on a production server before scheduling a maintenance reboot. Which command provides this information most directly?

Accepted Answer

uname -r. The running kernel is exposed directly by uname -r, which returns the release string of the kernel currently executing. Package queries and /boot listings describe installed images, which can differ from the active one after an upgrade until a reboot. /proc/version also works but is less focused. For a quick, unambiguous check before maintenance, uname -r is the appropriate command.

Answer

cat /proc/version

Answer

ls /boot/vmlinuz*

Answer

rpm -qa | grep kernel

Question 2

An administrator maintains an Apache HTTPD 2.4 server that proxies requests to a backend application. Users report that the application receives the proxy server's IP address in the client address field instead of the real client IP. The administrator wants the backend to see the original client IP when requests pass through the proxy. Which directive, used together with mod_remoteip, achieves this?

Accepted Answer

RemoteIPHeader X-Forwarded-For. mod_remoteip replaces the apparent client address with the value from a header named by RemoteIPHeader, commonly X-Forwarded-For. Trusted upstream proxies must also be declared with RemoteIPInternalProxy or RemoteIPTrustedProxy so spoofed headers from untrusted sources are ignored. The other directives affect host headers, environment variables, or trust lists without identifying the header that carries the client IP.

Answer

RemoteIPTrustedProxy 10.0.0.0/8

Answer

SetEnvIf X-Forwarded-For "^(.+)$" REMOTE_ADDR=$1

Answer

ProxyPreserveHost On

Question 3

A Linux server running a distribution kernel boots normally, but the administrator needs to add the boot parameter 'nomodeset' persistently to the kernel command line. Which file should be edited on a GRUB 2 system to make this change survive kernel updates?

Accepted Answer

/etc/default/grub. To persistently add a kernel boot parameter on a GRUB 2 system, the administrator edits /etc/default/grub and places the parameter in GRUB_CMDLINE_LINUX or GRUB_CMDLINE_LINUX_DEFAULT, then regenerates the configuration with grub-mkconfig or update-grub. This ensures the parameter is included in all generated boot entries and survives kernel updates, unlike direct edits to grub.cfg.

Answer

/etc/sysctl.conf

Answer

/boot/grub/grub.cfg

Answer

/etc/grub.conf

Question 4

A technician is preparing a new 500 GB SATA disk at /dev/sdc. The disk must contain a single GPT partition table with one partition spanning the entire disk, and the partition type must be set for Linux filesystems. Which command creates the GPT label on the disk?

Accepted Answer

parted /dev/sdc mklabel gpt. Creating a GPT partition table is a distinct step performed before any partitions exist. The parted mklabel gpt command writes the GUID Partition Table to the disk non-interactively, which is why it fits the requirement. Commands such as mkpart, interactive fdisk sequences, or nonexistent mkfs helpers either operate on an existing label or address the wrong layer entirely.

Answer

parted /dev/sdc mkpart primary 0% 100%

Answer

mkfs.gpt /dev/sdc

Answer

fdisk /dev/sdc then press g to create a new GPT disklabel

Question 5

A server has a software RAID5 array /dev/md0 built from four SATA disks. After a power loss, the array assembles but shows one member as faulty. The administrator replaces the failed disk with an identical model and partitions it to match the others. Which command should be used to add the new partition to the array and begin reconstruction?

Accepted Answer

mdadm --add /dev/md0 /dev/sde1. Replacing a failed member of an active RAID array requires hot-adding the new device as a spare. The mdadm --add command performs this and triggers a rebuild on a degraded RAID5 array. The grow option reshapes geometry, re-add expects prior membership, and assemble activates a stopped array, so none of them fit the replacement scenario.

Answer

mdadm --assemble /dev/md0 /dev/sde1

Answer

mdadm --re-add /dev/md0 /dev/sde1

Answer

mdadm --grow /dev/md0 --raid-devices=4

Question 6

An administrator wants to verify that a file on a Linux server has not been altered since a known-good baseline. A SHA-256 checksum was recorded earlier and stored separately. Which command lets the administrator recompute the digest and compare it with the stored value?

Accepted Answer

sha256sum /path/to/file. Integrity verification against a stored checksum requires recomputing the same algorithm. Since the baseline was recorded with SHA-256, sha256sum is the matching tool. MD5 yields a different digest, signature verification needs a signature and keyring, and decryption is an unrelated operation. Only rehashing with the same algorithm enables a meaningful comparison.

Answer

md5sum /path/to/file

Answer

openssl enc -d -aes-256-cbc -in /path/to/file

Answer

gpg --verify /path/to/file

Question 7

A junior administrator needs to check the contents of a zone file for syntax errors before reloading BIND. Which command is specifically designed to verify the syntax of a BIND zone file and report errors without loading it into the running server?

Accepted Answer

named-checkzone. named-checkzone is the BIND tool dedicated to verifying zone file syntax and integrity. It allows an administrator to catch errors before reloading the server, whereas named-checkconf checks configuration files, dig queries live data, and rndc reload applies changes without validation.

Answer

rndc reload

Answer

dig

Answer

named-checkconf

Question 8

A Linux server runs Samba to share a directory with Windows clients, and the administrator wants to ensure that the share is discoverable in the network neighborhood and that clients can resolve the server by its NetBIOS name. Which two smb.conf global parameters should be configured to achieve this? (Choose two.)

Accepted Answer

wins support = yes. NetBIOS name resolution and discovery require the server to have a defined NetBIOS name and a mechanism to register and resolve it. Setting netbios name gives the server its identity, while enabling wins support lets Samba act as a WINS server so clients can resolve that name. Together they satisfy the discovery and resolution requirements.

Answer

server string = File Server

Answer

preferred master = yes

Answer

disable netbios = yes

Question 9

An administrator is configuring a Samba server to share a directory with Windows clients. The share is defined in smb.conf with the path /srv/samba/share. The administrator wants to ensure that only users in the 'sales' group can access the share, and that new files created in the share are group-owned by 'sales'. Which TWO additional settings are required in the share definition to meet these requirements? (Choose two.)

Accepted Answer

valid users = @sales. The correct settings are 'valid users = @sales' and 'force group = sales'. The first restricts share access to members of the sales group, ensuring only they can connect. The second forces all newly created files and directories to be owned by the sales group, satisfying the group ownership requirement. Together, they meet both conditions. Other parameters like 'write list' or 'create mask' do not fully address the access restriction or group ownership.

Answer

create mask = 0770

Answer

browseable = no

Answer

write list = @sales

Question 10

A storage administrator is reviewing a server that uses LVM snapshots of an XFS logical volume to provide consistent point-in-time copies for nightly backups. Which two statements about LVM snapshot behavior on this system are correct? (Choose two.)

Accepted Answer

Writing to the origin volume triggers copy-on-write, moving original chunks into the snapshot's exception store.. Classic LVM snapshots preserve a point-in-time view through copy-on-write: the first modification to an origin chunk copies the original data into the snapshot's exception store. The snapshot's capacity limits how much origin change it can track. Once that store fills completely, the snapshot is invalidated and unusable, which is why sizing must match the expected write volume during the snapshot's lifetime, not the origin's total size.

Answer

A snapshot of an XFS volume can be safely resized with lvextend while it is active.

Answer

The snapshot must be at least as large as the origin volume to guarantee it never fills.

Answer

Because the origin runs XFS, the snapshot must be mounted with the norecovery option before backup tools can read it.

Question 11

An administrator is configuring a Linux server to act as a DHCP relay agent for a remote subnet 192.168.2.0/24. The DHCP server is at 10.0.0.5. The server has an interface eth1 on the 192.168.2.0/24 network. Which command correctly starts the DHCP relay?

Accepted Answer

dhcrelay -i eth1 10.0.0.5. The dhcrelay command is part of the ISC DHCP package. To relay DHCP requests from a subnet, you specify the interface facing that subnet with -i and the DHCP server address as an argument. The correct syntax is 'dhcrelay -i eth1 10.0.0.5'. Using the wrong interface or incorrect option order prevents the relay from functioning.

Answer

dhcrelay -i eth0 10.0.0.5

Answer

dhcrelay 10.0.0.5 -i eth1

Answer

dhcrelay --interface eth1 --server 10.0.0.5

Question 12

A Linux server uses PAM for authentication. The administrator wants to ensure that after five failed login attempts, a user account is locked for 10 minutes. Which PAM module and configuration should be used?

Accepted Answer

pam_faillock.so with deny=5 and unlock_time=600. The pam_faillock.so module is designed to lock user accounts after a specified number of failed authentication attempts (deny=5) and automatically unlock them after a defined period (unlock_time=600 seconds). It is the current standard for this functionality, replacing the older pam_tally2.so. The other modules either lack these capabilities or are deprecated.

Answer

pam_unix.so with maxlogins=5 and lock_time=600

Answer

pam_tally2.so with deny=5 and unlock_time=600

Answer

pam_limits.so with deny=5 and unlock_time=600

Question 13

A software RAID5 array md0 is built from four 2 TB disks and is currently clean. The administrator adds a fifth 2 TB disk and runs mdadm --grow --raid-devices=5 /dev/md0. Users report the array is responsive but a status check shows a resync in progress. Which statement describes the state of the array?

Accepted Answer

The array is fully redundant and online while it redistributes data across all five members.. Growing a RAID5 array by adding a device triggers a reshape in which data and parity are redistributed across the larger set of members. Throughout this operation the array remains online and keeps its single-disk fault tolerance, so it is not degraded. Administrators can monitor progress through the sync action and speed fields reported for the array.

Answer

The grow operation has failed because RAID5 requires a power-of-two device count.

Answer

The array is degraded and cannot tolerate any disk failure until reshaping completes.

Answer

Data is being copied to the new disk by a background rebuild that temporarily removes parity.

Question 14

An administrator is troubleshooting a Linux client that uses LDAP for user authentication. The client is configured with nss-pam-ldapd and /etc/nsswitch.conf contains 'passwd: files ldap'. Users cannot log in, and the log shows 'nslcd: [8b4567] failed to bind to LDAP server: Invalid credentials'. Which action will most directly resolve the bind failure?

Accepted Answer

Verify and correct the binddn and bindpw credentials in /etc/nslcd.conf. The message 'failed to bind to LDAP server: Invalid credentials' points to nslcd being unable to authenticate to the directory. nslcd uses the binddn and bindpw directives from /etc/nslcd.conf to perform searches. If these are incorrect or absent, the bind fails and no user lookups can occur. Correcting the credentials to a valid account restores the bind and allows authentication to function.

Answer

Add 'ldap' to the shadow line in /etc/nsswitch.conf

Answer

Restart the nscd service to clear cached credentials

Answer

Change the LDAP URI in /etc/ldap/ldap.conf to use ldaps://

Question 15

A server has two paths to a SAN LUN, /dev/sdb and /dev/sdc, and multipath -ll reports a single mpath device with one active and one standby path. The administrator wants I/O to use both paths simultaneously for higher throughput. Which action is required?

Accepted Answer

Set path_grouping_policy to multibus in the multipath configuration and reload the maps.. Aggregate throughput across multiple paths requires the paths to share one priority group, which the multibus grouping policy accomplishes. With all paths in a single group, the path selector can distribute I/O across them. Standby grouping, by contrast, deliberately keeps one group active and the rest passive for failover only.

Answer

Increase the queue_if_no_path timeout so both paths remain queued and usable.

Answer

Enable the retain_attached_hw_handler option and restart the multipathd service.

Answer

Change the path_selector to round-robin and run multipath -r without altering grouping.