Index

A

• active processes, troubleshooting
  • server performance, tuning with memory management and swap / Tuning server performance with memory management and swap
  • memory, managing with vmstat / Managing memory with vmstat
  • system load, checking with top command / Checking the system load with the top command
  • disk I/O, monitoring with iotop / Monitoring disk I/O with iotop
  • processes, checking with ps command / Checking processes with the ps command
  • performance, checking with iostat and lsof / Checking performance with iostat and lsof
  • system load, calculating / Calculating the system load
  • process IDs, discovering with pgrep and systemctl / Discovering process IDs with pgrep and systemctl
  • systemd / More about systemd
  • kill signal, issuing / Issuing the kill signal
  • orphaned process, dealing with / Dealing with an orphaned process
• Age / Testing Varnish with cURL
• Akamai headers
  • debugging, with cURL / Debugging Akamai headers with cURL
• Apache
  • Varnish, adding to / Adding Varnish to Apache
  • mod_status, enabling / Enabling mod_status in Apache
• aureport utility / Auditing SELinux with aureport and setroubleshoot
• autofs
  • used, for mounting external drive / Using autofs to mount an external drive

B

• bandwidth
  • monitoring, with iftop / Monitoring bandwidth with iftop
• BIND
  • used, for performing system sanity checks / Performing system sanity checks with BIND

C

• cache
  • flushing / Flushing the cache
• cat command
  • about / Using cat, less, and more
• CentOS
  • basic tools, installing / Installing some basic tools
  • hardware information, obtaining / Gathering hardware information
  • dmesg / Understanding dmesg
  • log files / Understanding log files
  • log files, reading / Reading log files and affecting the output
  • log files, monitoring with tail / Using tail to monitor log files
  • cat command, using / Using cat, less, and more
  • grep, using / Using grep
  • diff, using / Using diff
  • truncation, using / Using truncation
  • references / References
• CentOS 7 server
  • NFS shares, providing on / Providing NFS shares on a CentOS 7 server
• CentOS client
  • NFS shares, mounting on / Mounting NFS shares on a CentOS client
• CIFS
  • used, for mounting external drive / Mounting an external drive with CIFS
• corrupt RPM database
  • diagnosing / Diagnosing a corrupt RPM database
• cpio command / Downloading an RPM package with Yum
• cURL
  • server, auditing with / Auditing the server with cURL
  • Akamai headers, debugging with / Debugging Akamai headers with cURL
  • Varnish, testing with / Testing Varnish with cURL
  • used, for accessing FTP directory / Using cURL to access an FTP directory

D

• deleted files
  • recovering, with Scalpel / Recovering lost or deleted files with Scalpel
• demsg file
  • about / Understanding dmesg
• diff command
  • about / Using diff
  • using / Using diff
• dig command
  • about / The dig and host commands
  • using / The dig and host commands
• directories
  • auditing / Auditing directories and files
  • visualizing / Visualizing directories and files
• disk I/O
  • monitoring, with iotop / Monitoring disk I/O with iotop
• dmesg command
  • about / Understanding dmesg
• DNS services, troubleshooting
  • hostname, changing / Changing the hostname and managing the FQDN
  • FQDN, managing / Changing the hostname and managing the FQDN
  • system sanity checks, performing with BIND / Performing system sanity checks with BIND
  • bandwidth, monitoring with iftop / Monitoring bandwidth with iftop
  • cache, flushing / Flushing the cache

E

• external drive
  • mounting on CentOS 7, CIFS used / Mounting an external drive with CIFS
  • mounting, autofs used / Using autofs to mount an external drive
• Extra Packages for Enterprise Linux (EPEL) repository
  • about / EPEL

F

• file
  • directory permissions / Restoring file and directory permissions
• files
  • restoring / Restoring file and directory permissions
  • auditing / Auditing directories and files
  • visualizing / Visualizing directories and files
• Firewalld
  • about / Firewalld – zone, service, and port management
  • running / Firewalld – zone, service, and port management
  • predefined zones, listing / Firewalld – zone, service, and port management
  • removing / Removing Firewalld and returning to iptables
  • returning, to iptables / Removing Firewalld and returning to iptables
• FQDN
  • managing / Changing the hostname and managing the FQDN
• fragmentation
  • investigating, on XFS / Investigating fragmentation on XFS
• FTP directory
  • accessing, with cURL / Using cURL to access an FTP directory

G

• grep command
  • about / Using grep
  • using / Using grep

H

• hardware information
  • obtaining / Gathering hardware information
• hop count / The ping command
• host-based intrusion detection system (HIDS) / Intrusion detection with Tripwire
• host command
  • using / The dig and host commands
  • about / The dig and host commands
• hostname
  • changing / Changing the hostname and managing the FQDN

I

• intrusion detection
  • with Tripwire / Intrusion detection with Tripwire
• iostat command
  • used, for checking performance / Checking performance with iostat and lsof
• iotop
  • used, for monitoring disk I/O / Monitoring disk I/O with iotop
• IUS repository
  • about / The IUS repository

K

• kill signal
  • issuing / Issuing the kill signal

L

• log files
  • about / Understanding log files
  • /var/log/messages / Understanding log files
  • /var/log/boot.log / Understanding log files
  • /var/log/maillog / Understanding log files
  • /var/log/secure / Understanding log files
  • /var/log/wtmp / Understanding log files
  • /var/log/btmp / Understanding log files
  • /var/log/cron / Understanding log files
  • /var/log/lastlog / Understanding log files
  • /var/log/yum.log / Understanding log files
  • reading / Reading log files and affecting the output
  • log level values / Reading log files and affecting the output
• lsof command
  • used, for checking performance / Checking performance with iostat and lsof

M

• MariaDB
  • obtaining / Getting up-and-running with MariaDB
  • installing / Getting up-and-running with MariaDB
  • root password, recovering with / Resetting and recovering a root password with MariaDB
  • root password, resetting with / Resetting and recovering a root password with MariaDB
  • tuning / Tuning MariaDB and MySQL
  • metrics, obtaining from / Obtaining metrics from MariaDB and MySQL
• memory
  • managing, with vmstat / Managing memory with vmstat
• metrics
  • obtaining, from MariaDB and MySQL / Obtaining metrics from MariaDB and MySQL
• minor release upgrades / Minor release upgrades
• mod_status
  • about / Enabling mod_status in Apache
  • enabling, in Apache / Enabling mod_status in Apache
• mtr command
  • about / The mtr command
  • using / The mtr command
• MySQL
  • tuning / Tuning MariaDB and MySQL
  • metrics, obtaining from / Obtaining metrics from MariaDB and MySQL
  • returning to / Returning to MySQL

N

• network connections
  • monitoring, with ss command / Monitoring network connections with the ss command
• network environment, troubleshooting
  • ping command, using / The ping command
  • dig command, using / The dig and host commands
  • host command, using / The dig and host commands
  • traceroute command, using / The traceroute command
  • mtr command, using / The mtr command
  • packet analysis, with tcpdump / Packet analysis with tcpdump
• NFS exports
  • about / About NFS exports
  • no_all_squash / About NFS exports
  • rw / About NFS exports
  • ro / About NFS exports
  • sync / About NFS exports
  • async / About NFS exports
  • secure / About NFS exports
  • insecure / About NFS exports
  • wdelay / About NFS exports
  • no_wdelay / About NFS exports
  • subtree_check / About NFS exports
  • no_subtree_check / About NFS exports
  • anonuid=UID / About NFS exports
  • anongid=GID / About NFS exports
• NFS shares
  • providing, on CentOS 7 server / Providing NFS shares on a CentOS 7 server
  • mounting, on CentOS client / Mounting NFS shares on a CentOS client

O

• orphaned process
  • dealing with / Dealing with an orphaned process

P

• performance
  • checking, with iostat and lsof / Checking performance with iostat and lsof
• pgrep command
  • used, for discovering process IDs / Discovering process IDs with pgrep and systemctl
• ping command
  • about / The ping command
  • using / The ping command
• PostgreSQL 9
  • installing / Installing and configuring PostgreSQL 9
  • configuring / Installing and configuring PostgreSQL 9
• predefined zones, Firewalld
  • drop / Firewalld – zone, service, and port management
  • block / Firewalld – zone, service, and port management
  • public / Firewalld – zone, service, and port management
  • external / Firewalld – zone, service, and port management
  • dmz / Firewalld – zone, service, and port management
  • work/home/internal / Firewalld – zone, service, and port management
  • trusted / Firewalld – zone, service, and port management
• processes
  • checking, with ps command / Checking processes with the ps command
• process IDs
  • discovering, with pgrep and systemctl / Discovering process IDs with pgrep and systemctl
• ps command
  • used, for checking processes / Checking processes with the ps command

R

• Remi repository
  • about / Remi
• repairs
  • running, on XFS / Running repairs on XFS
• root password
  • resetting / Resetting the root password and enhancing logging
  • recovering, with MariaDB / Resetting and recovering a root password with MariaDB
  • resetting, with MariaDB / Resetting and recovering a root password with MariaDB
• RPM package
  • downloading, with Yum / Downloading an RPM package with Yum

S

• Scalpel
  • about / Recovering lost or deleted files with Scalpel
  • used, for recovering files / Recovering lost or deleted files with Scalpel
• SELinux
  • auditing, with aureport and setroubleshoot / Auditing SELinux with aureport and setroubleshoot
• server
  • auditing, with cURL / Auditing the server with cURL
• Server Message Block (SMB) / Mounting an external drive with CIFS
• server performance
  • tuning, with memory management and swap / Tuning server performance with memory management and swap
• setroubleshoot tool / Auditing SELinux with aureport and setroubleshoot
• software information
  • obtaining / Gathering software information
• ss command
  • used, for monitoring network connections / Monitoring network connections with the ss command
• SSH
  • tuning / Tuning SSH
• SSH banners
  • using / SSH banners
• systemd command
  • about / More about systemd
• systemd system
  • about / More about systemd
• system load
  • checking, with top command / Checking the system load with the top command
  • about / Calculating the system load
  • calculating / Calculating the system load
• system sanity checks
  • performing, with BIND / Performing system sanity checks with BIND

T

• tail command
  • used, for monitoring log files / Using tail to monitor log files
  • about / Using tail to monitor log files
• tcpdump command
  • about / Packet analysis with tcpdump
  • used, for packet analysis / Packet analysis with tcpdump
• top command
  • used, for checking system load / Checking the system load with the top command
• traceroute command
  • about / The traceroute command
  • using / The traceroute command
  • objectives / The traceroute command
• Tripwire
  • about / Intrusion detection with Tripwire
  • used, for intrusion detection / Intrusion detection with Tripwire
• truncation
  • about / Using truncation
  • using / Using truncation

U

• user activity
  • monitoring, with utmpdump / Monitoring user activity with utmpdump
• user management
  • about / Users
  • users, adding / Adding users and forcing a password change
  • password change, forcing / Adding users and forcing a password change
  • users, deleting / Deleting users
  • users, modifying / Modifying a user
  • login.defs / Meet login.defs
• utmpdump / Monitoring user activity with utmpdump

V

• Varnish
  • about / Adding Varnish to Apache
  • adding, to Apache / Adding Varnish to Apache
  • testing, with cURL / Testing Varnish with cURL
• vmstat
  • used, for managing memory / Managing memory with vmstat

W

• web services, troubleshooting
  • server, auditing with cURL / Auditing the server with cURL
  • Akamai headers, debugging with cURL / Debugging Akamai headers with cURL
  • Varnish, adding to Apache / Adding Varnish to Apache
  • Varnish, testing with cURL / Testing Varnish with cURL
  • FTP directory, accessing with cURL / Using cURL to access an FTP directory
  • mod_status, enabling in Apache / Enabling mod_status in Apache

X

• X-Cache / Debugging Akamai headers with cURL
  • TCP_HIT / Debugging Akamai headers with cURL
  • TCP_MISS / Debugging Akamai headers with cURL
  • TCP_REFRESH_HIT / Debugging Akamai headers with cURL
  • TCP_REFRESH_MISS / Debugging Akamai headers with cURL
  • TCP_REFRESH_FAIL_HIT / Debugging Akamai headers with cURL
  • TCP_IMS_HIT / Debugging Akamai headers with cURL
  • TCP_NEGATIVE_HIT / Debugging Akamai headers with cURL
  • TCP_DENIED / Debugging Akamai headers with cURL
  • TCP_COOKIE_DENY / Debugging Akamai headers with cURL
• X-Cache-Key / Debugging Akamai headers with cURL
• X-Check-Cacheable / Debugging Akamai headers with cURL
• X-Varnish / Testing Varnish with cURL
• XFS
  • repairs, running / Running repairs on XFS
  • fragmentation, investigating / Investigating fragmentation on XFS
• XFS filesystem
  • working with / Working with and extending the XFS filesystem
  • extending / Working with and extending the XFS filesystem

Y

• Yum
  • about / Using Yum plugins
  • additional repositories,installing / Installing additional Yum repositories
• Yum operations
  • fixing / Fixing Yum operations
• Yum plugins
  • using / Using Yum plugins
• Yum repositories
  • EPEL / EPEL
  • Remi / Remi
  • IUS repository / The IUS repository
• YUM repository configuration file
  • URL / Returning to MySQL