Data Center, Storage & Virtualization

Where systems physically run: the buildings, racks, power and cooling behind every server, the storage that holds the data, the virtualization clusters on top, and the backups and second sites that bring it all back when something fails.

19 pages 128 glossary terms Server+

How to use this topic

The first six pages are about the facility: what a data center is, how its resilience is classified, racks and cabling, power, cooling, and physical security. The next seven cover the equipment inside: servers and their management controllers, the kinds of storage, how storage is attached and shared, and what storage arrays and software-defined storage do. The last six are about running it: virtualization clusters, the data center network, backup, disaster recovery, daily operations and energy use.

Hypervisors and virtual machines are introduced in Virtualization and Hypervisors, disks and RAID in Hardware, and switching in Networking; these pages link there and focus on the data center.

Pages about servers, storage, virtualization, backup, disaster recovery and the physical side of a server room are tagged Server+ (CompTIA Server+). The introduction and the pages on availability tiers, software-defined storage, data center networking and energy go beyond that exam and are untagged.

Learning path

  1. 01What Is a Data Center?What a data center is and why organizations still run or rent one: on-premises, colocation, hyperscale and edge facilities, what is inside, and who works there.Beginner
  2. 02Availability Tiers and RedundancyHow data centers are classified by resilience: the Uptime Institute Tiers, EN 50600 availability classes, and what N, N+1 and 2N redundancy really mean.Beginner
  3. 03Racks, Rack Units and CablingThe 19-inch rack and the rack unit, rack PDUs, structured cabling between racks, and the labeling and documentation that keep a data center manageable.BeginnerServer+
  4. 04Power: Utility, UPS and GeneratorsHow power reaches a server without interruption: utility feeds, uninterruptible power supplies, generators, transfer switches, A/B feeds and power budgets.IntermediateServer+
  5. 05Cooling and AirflowWhy every watt becomes heat and how data centers remove it: hot and cold aisles, containment, recommended temperatures, liquid cooling for dense AI racks, and PUE.IntermediateServer+
  6. 06Physical Security and Environmental MonitoringKeeping people, fire and water away from the equipment: access control layers, mantraps, fire detection and suppression, and sensors that warn before something breaks.BeginnerServer+
  7. 07Servers: Rack, Blade and HyperconvergedWhat makes a server different from a PC, and the main form factors in a data center: rack servers, blade chassis and hyperconverged nodes, with redundant parts and hot-swap.BeginnerServer+
  8. 08Out-of-Band ManagementManaging a server when its operating system is down: baseboard management controllers, iDRAC and iLO, IPMI and Redfish, console servers, and how to keep the management network safe.IntermediateServer+
  9. 09Storage Fundamentals: Block, File and ObjectThe three ways systems store and reach data — block, file and object storage — what each one is good at, and the numbers that matter: capacity, IOPS, throughput and latency.BeginnerServer+
  10. 10DAS, NAS and SANThree ways to attach storage to servers: direct-attached storage, network-attached storage for shared files, and storage area networks for shared block storage.BeginnerServer+
  11. 11SAN Protocols: Fibre Channel, iSCSI and NVMe over FabricsHow servers talk to shared block storage: Fibre Channel fabrics with WWNs and zoning, iSCSI over ordinary Ethernet, NVMe over Fabrics, and multipathing for redundancy.IntermediateServer+
  12. 12Storage Arrays in PracticeWhat happens inside a storage array: LUNs and volumes, thin provisioning, snapshots, clones, deduplication, compression and tiering — and the traps that come with them.IntermediateServer+
  13. 13Software-Defined Storage and Hyperconverged InfrastructureStorage built from ordinary servers instead of a dedicated array: software-defined storage such as Ceph, and hyperconverged infrastructure that combines compute and storage in one cluster.Intermediate
  14. 14Data Center Virtualization in PracticeRunning many virtual machines on a cluster of hosts: vSphere, Hyper-V, Proxmox and KVM, shared storage, live migration, high availability, load balancing, and the licensing changes since Broadcom bought VMware.IntermediateServer+
  15. 15Data Center NetworkingHow servers inside a data center are connected: top-of-rack switches, spine-leaf fabrics built for east-west traffic, VXLAN and EVPN overlays, and the link speeds in use today.Intermediate
  16. 16Backup and RecoveryMaking sure data can come back: full, incremental and differential backups, the 3-2-1-1-0 rule, immutable and offline copies against ransomware, tape, and why only a tested restore counts.BeginnerServer+
  17. 17Disaster Recovery and Site ResilienceSurviving the loss of a whole data center: RPO and RTO in practice, synchronous and asynchronous replication, active-active and active-passive sites, and how to test a DR plan.IntermediateServer+
  18. 18Operations and LifecycleRunning a data center day to day: DCIM and documentation, capacity planning, remote hands, changes on the floor, and the hardware lifecycle from delivery to secure data destruction.IntermediateServer+
  19. 19Energy and SustainabilityHow much energy data centers use and how it is measured and reported: PUE, WUE and renewable energy, reporting rules per region, residual heat reuse, and the Dutch context of grid congestion and siting rules.Intermediate

Data Center, Storage & Virtualization glossary

Short definitions of the terms used in this topic. The full glossary covers every topic.