LPIC-2 Practice Test 3 — 10 Questions

Question 1

Refer to the exhibit. What is the effect of this sudoers configuration?

Accepted Answer

Users alice and bob can run apt-get and dpkg on any host as root, requiring a password.. The sudoers configuration specifies that users alice and bob are allowed to run only the commands /usr/bin/apt-get and /usr/bin/dpkg as root on any host (ALL). The absence of the NOPASSWD tag means that a password is required for these commands. The syntax 'alice,bob ALL=(root) /usr/bin/apt-get, /usr/bin/dpkg' restricts the command set and requires authentication.

Answer

Users alice and bob can run any software command on the localhost only.

Answer

Members of ADMINS can run any command as root on any host.

Answer

Users alice and bob can run apt-get and dpkg without a password.

Question 2

A Samba share is intended for guest (anonymous) access. Which global parameter must be set to allow this?

Accepted Answer

map to guest = Bad User. The `map to guest = Bad User` parameter in Samba's global configuration forces any connection attempt with an invalid or non-existent username to be treated as a guest (anonymous) login. This is the standard way to allow anonymous access to shares while still using `security = user` (the default in modern Samba), as it maps failed authentication to the guest account.

Answer

guest account = nobody

Answer

security = share

Answer

security = user

Question 3

A Linux system administrator is tasked with upgrading the kernel on a server running a custom compiled kernel (version 4.19) with many in-house modules. The new kernel (5.10) has significant changes, including a different API for some module functions. After compiling the new kernel and the modules, the system boots but some modules fail to load with 'Unknown symbol' errors. The administrator needs to identify which symbols are missing and fix the modules. Which of the following is the most effective approach?

Accepted Answer

Run 'modprobe --dump-modversions mymodule.ko' and compare with 'cat /proc/kallsyms' to identify mismatches. `modprobe --dump-modversions mymodule.ko` displays the symbol version (CRC) checksums for each symbol the module uses, and comparing these with `/proc/kallsyms` (which lists all symbols exported by the running kernel along with their CRC values) directly pinpoints which symbols have mismatched versions. This is the most efficient method to identify 'Unknown symbol' errors caused by API changes between kernel 4.19 and 5.10, as it reveals exactly which symbols need updating in the module source code.

Answer

Check dmesg for each module load error and recompile modules one by one

Answer

Rename the missing symbols in the source code to match the new kernel's exported symbols

Answer

Use 'nm mymodule.ko' to list all symbols and manually compare with the kernel's symbol table

Question 4

An administrator notices that an NFS mount on a client becomes unresponsive when the NFS server goes offline. The admin wants the mount to return an error to the application after a short timeout instead of hanging indefinitely. Which mount option should be added to the fstab entry?

Accepted Answer

soft. The `soft` mount option causes the NFS client to return an error to the application after a short timeout (typically 60 seconds by default) if the NFS server becomes unresponsive, rather than hanging indefinitely. This is the correct choice because the administrator specifically wants the mount to return an error after a short timeout instead of hanging.

Answer

intr

Answer

bg

Answer

hard

Question 5

A Linux client is configured with the following in /etc/nslcd.conf: 'uri ldap://10.0.0.1/', 'base dc=example,dc=com'. Which command can be used to test connectivity to the LDAP server and verify the base DN?

Accepted Answer

ldapsearch -x -H ldap://10.0.0.1 -b dc=example,dc=com. The `ldapsearch` command with `-x` (simple authentication), `-H ldap://10.0.0.1` (specifying the LDAP URI), and `-b dc=example,dc=com` (setting the search base DN) directly performs an anonymous LDAP search against the server. If the server is reachable and the base DN exists, it returns entries, confirming both connectivity and the validity of the base DN. This matches the configuration in `/etc/nslcd.conf` and is the standard tool for testing LDAP server responses.

Answer

authconfig --test

Answer

getent passwd

Answer

nslcd -d

Question 6

Which command is used to list the NFS exports available from a specific server?

Accepted Answer

showmount -e server. The `showmount -e server` command queries the NFS server's mount daemon (rpc.mountd) to list the exported filesystems that are currently available. This is the standard method for a client to discover which NFS shares a server is offering, as it directly interrogates the server's export list via the RPC protocol.

Answer

mount -t nfs4 server:/export /mnt

Answer

nfsstat

Answer

exportfs -a

Question 7

A Samba server is configured with 'security = ads' and joined to an Active Directory domain. Users can authenticate but cannot access shares. The smb.conf includes 'winbind use default domain = yes'. What could be the problem?

Accepted Answer

The 'valid users' parameter uses domain prefix while default domain is set. When 'winbind use default domain = yes' is set, Winbind strips the domain prefix from usernames, so users authenticate as 'username' instead of 'DOMAIN\username'. If the 'valid users' parameter in a share definition explicitly uses the domain prefix (e.g., 'valid users = DOMAIN\username'), the stripped username will not match, and access is denied. This mismatch is the most direct cause of authentication succeeding but share access failing.

Answer

The 'winbind use default domain' option should be 'no'

Answer

The 'idmap backend' is not configured

Answer

The Samba server's time is not synchronized with the domain controller

Question 8

A Samba server experiences slow file transfers for large files. The administrator suspects oplock issues. Which set of parameters should be adjusted to disable opportunistic locking?

Accepted Answer

oplocks = no and level2 oplocks = no. Disabling opportunistic locking (oplocks) in Samba requires setting both 'oplocks = no' and 'level2 oplocks = no'. The 'oplocks = no' directive disables exclusive oplocks, but Samba's default behavior still allows level2 oplocks (read-only caching). To fully disable all forms of oplock caching, both parameters must be set to 'no', preventing client-side caching that can cause conflicts and slow transfers for large files.

Answer

oplocks = false alone is sufficient

Answer

strict locking = yes

Answer

kernel oplocks = no

Question 9

Refer to the exhibit. What is the most likely cause of this Apache error?

Accepted Answer

The semaphore limit for the Apache user is exceeded.. The Apache error 'semaphore limit exceeded' occurs when the number of semaphores allocated to the Apache user exceeds the system-wide or per-user semaphore limit. Apache uses semaphores for inter-process communication (IPC) in its prefork or worker MPMs to coordinate child processes. The correct answer is C because this error directly indicates that the kernel's semaphore limits (e.g., `SEMMSL`, `SEMMNS`, or `SEMOPM` in `/proc/sys/kernel/sem`) have been exhausted for the Apache user, often due to too many child processes or a misconfigured `MaxClients` directive.

Answer

The filesystem containing the logs is full.

Answer

The server is out of memory.

Answer

The RewriteMap file specified is missing.

Question 10

A database server experiences performance degradation. Analysis shows high I/O wait on a LVM logical volume that uses striping across two physical volumes. What is the most effective way to improve performance?

Accepted Answer

Add a cache layer using lvmcache on a fast SSD. Adding a cache layer using lvmcache on a fast SSD is the most effective way to reduce high I/O wait because it places frequently accessed (hot) data on the faster SSD while keeping the bulk of data on the slower striped HDDs. This directly addresses the I/O bottleneck without requiring data migration or downtime, and it leverages the existing striped layout for sequential throughput while improving latency for random reads/writes.

Answer

Increase the stripe size and recreate the LV

Answer

Add an additional PV to the VG and extend the LV

Answer

Convert the LV to use linear mapping instead of striping