RHEL (3-9) CentOS (5-9) Scientific Linux Fedora Debian Ubuntu (LTS) SLES Rocky Linux AlmaLinux Oracle Linux Amazon Linux Gentoo Arch Mint Alpine

HP-UX (11.x) AIX (5L-7.x) Solaris (8-11) Tru64 IRIX FreeBSD OpenBSD

Oracle VM (OVM) Server/Manager Oracle Linux Virtualization Manager (OLVM) KVM QEMU libvirt virt-manager oVirt Proxmox VE VMware vSphere (ESXi) vCenter VMware Workstation/Fusion Microsoft Hyper-V Xen XenServer XCP-ng Nutanix AHV Acropolis Prism OpenStack (Nova, Neutron, Cinder) Red Hat Virtualization (RHV) RHEV Citrix Hypervisor VirtualBox Vagrant Packer CloudStack OpenNebula VM lifecycle Templates/Cloning Snapshots Live Migration (vMotion) High Availability (HA) Fault Tolerance DRS Resource Pools Storage (VMFS, NFS, OVM repo, Ceph RBD, Nutanix DSF) Virtual Networking (vSwitch, OVS, VXLAN, SR-IOV) P2V/V2V migration VMware Converter virt-p2v/virt-v2v

Apache HTTPD Nginx Tomcat JBoss WildFly Postfix Sendmail Exim Dovecot Courier Bind (named) Unbound PowerDNS dhcpd kea Samba (AD DC) NFS (v3/v4) vsftpd proftpd pure-ftpd OpenLDAP 389-ds sssd FreeIPA ntpd chrony rsyslog syslog-ng logrotate cron anacron CUPS lpd Redis Memcached RabbitMQ MySQL/MariaDB PostgreSQL SQLite MongoDB

Ansible Ansible Tower/AWX Puppet PuppetDB Foreman Chef SaltStack Terraform CloudFormation Pulumi Bash Python Perl Ruby Expect awk sed Kickstart Preseed AutoYaST Cobbler Spacewalk Red Hat Satellite (5/6) ULN RHSM GitHub Actions GitLab CI

Docker Podman Buildah Skopeo Kubernetes OpenShift LXC LXD containerd CRI-O rkt Docker Swarm Helm Kustomize Rancher Portainer K3s MicroK8s Minikube Kind OKD

Veritas Cluster (VCS) Red Hat Cluster Suite (RHCS) Pacemaker Corosync Keepalived HAProxy heartbeat DRBD GlusterFS Ceph OCFS2 GFS2 Cluster LVM Oracle RAC Microsoft Failover Cluster VMware HA/FT Nutanix HA Stretched clusters Metro clusters

LVM2 mdadm (software RAID) iSCSI FC SAN NAS NFS Samba/CIFS GlusterFS Ceph DRBD ext2/ext3/ext4 XFS ZFS Btrfs JFS ReiserFS FUSE autofs udev multipath device-mapper NTFS FAT OCFS2 VMFS Nutanix DSF

TCP/IP UDP ICMP ARP VLAN trunking bonding teaming bridging routing NAT port forwarding tunneling iptables nftables firewalld ebtables arptables tcpdump wireshark/tshark nmap netstat ss iproute2 ethtool mii-tool bridge-utils openvswitch OpenVPN WireGuard IPsec PPTP L2TP GRE VXLAN GENEVE DNS (BIND, Unbound) DHCP (ISC, Kea) RADIUS TACACS+ Load balancing (HAProxy, Nginx, F5) WAF CDN

SELinux (targeted/mls) AppArmor Tomoyo Smack PAM LDAP authentication Kerberos RADIUS TACACS+ OpenSCAP Lynis chkrootkit rkhunter AIDE Tripwire OS hardening (CIS benchmarks, STIG) system auditing (auditd) logwatch fail2ban GPG OpenSSL CA management certificates Let's Encrypt SSH (keys, tunneling, forwarding) stunnel sslh Fortinet (Fortigate) Checkpoint F5 BigIP pfSense OPNsense Snort Suricata Security Onion Wazuh

Nagios Core Nagios XI Icinga Zabbix Prometheus Grafana Loki ELK Stack (Elasticsearch, Logstash, Kibana) Graylog Splunk Datadog New Relic SNMP (v1/v2c/v3) MRTG RRDtool Cacti Netdata collectd telegraf influxdb statsd Graphite rsyslog syslog-ng fluentd fluentbit sar iostat vmstat mpstat top htop atop nmon

Relax-and-Recover (ReaR) Double-Take Zerto Veeam tar cpio dump/restore dd rsync rdiff-backup Amanda Bacula Bareos BackupPC Duplicity Duplicati Clonezilla Partimage Partclone Mondo Rescue P2V/V2V tools VMware Converter StarWind Acronis Nutanix Leap Nutanix Metro Availability Native replication RPO/RTO planning DR testing Business continuity

AWS (EC2, S3, VPC, IAM, RDS, ELB, CloudWatch) Azure (VMs, Storage, VNet, AD, Backup) Google Cloud (Compute Engine, GKE, Cloud Storage) OpenStack (Nova, Neutron, Cinder, Glance, Keystone, Horizon) VMware Cloud on AWS Azure Stack Google Anthos Hybrid cloud architectures Cloud migrations Lift-and-shift Infrastructure as Code (IaC)

Git SVN CVS RCS GitHub GitLab Bitbucket GitFlow GitHub Actions GitLab CI Jenkins Bamboo TeamCity CircleCI Travis CI ArgoCD Flux

RPM DEB YUM APT DNF Zypper dpkg rpmbuild Red Hat Network (RHN) ULN EPEL Remi RPMForge Kickstart Preseed AutoYaST Firstboot cloud-init Cobbler Spacewalk Foreman Katello

GRUB (Legacy/2) LILO SYSLINUX ISOLINUX PXELINUX MBR GPT parted fdisk gdisk sfdisk init systemd SysVinit Upstart runit OpenRC initrd initramfs dracut mkinitrd

sysstat iostat vmstat mpstat pidstat sar top htop atop btop nmon glances perf strace ltrace gprof valgrind systemtap tuned numactl irqbalance cgroups ulimit kernel parameters (sysctl) swap tuning memory overcommit disk scheduler (CFQ, deadline, noop, mq-deadline, kyber) network tuning (sysctl net.*) TCP tuning socket buffers

journalctl dmesg kernel ring buffer strace ltrace gdb objdump nm readelf lsof fuser ps pstree kill pkill netstat ss lsof -i tcpdump tshark nmap ping traceroute mtr pathping tracepath dig nslookup host whois curl wget df du lsblk blkid fdisk -l parted smartctl badblocks fsck xfs_repair tune2fs vmstat iostat mpstat sar top -H