CompTIA Server+ case studies

CompTIA Server+ · Put your knowledge to work in context.

CompTIA Server+ is a vendor-neutral certification that validates skills in server installation, management, and troubleshooting, positioned for professionals working in data centers, on-premises, and hybrid environments. The current release is V5, exam series code SK0-005, launched May 18, 2021. The CompTIA Server+ case studies are 5 cases and about 4,713 words.

Memory upgrade on a NUMA-sensitive database host

A two-socket 2U database server runs an in-memory OLTP workload on two identical 24-core Xeon Scalable CPUs. Each CPU has eight memory channels and eight DIMM slots, for 16 slots total.

937 words, about 5 min 2

Firmware window on a five-host cluster at N+1

A five-host virtualization cluster runs 84 general-purpose VMs at 4 vCPU and 20 GB RAM with memory reservations set to 100%, plus six 64 GB, 8 vCPU SQL VMs whose replicas live at a DR site in another region. Each host has 32 physical cores and 512 GB RAM.

939 words, about 5 min 3

Ransomware: choosing the recovery point when the best backup is 7 hours old

A 40 TB file server and twelve SQL Server VMs were encrypted by ransomware at 09:40 on a Tuesday. The backup design in place is: hourly volume snapshots on the same SAN as production, nightly full plus hourly transaction-log backups to a NAS in the same room, a copy replicated to an immutable cloud bucket every six hours with the last successful sync at 02:00 Tuesday, and weekly tapes that go offsite on Fridays.

892 words, about 4 min 4

Periodic 40 ms write-latency spikes on a RAID 10 database server

An OLTP database running on bare metal shows a p95 write latency that jumps from about 2 ms to 45 ms for 25 to 40 minutes roughly every 30 days, then recovers on its own. Data lives on eight SAS SSDs in RAID 10 behind a hardware RAID controller with a 2 GB battery-backed cache.

921 words, about 5 min 5

Adding four nodes to a rack that is closer to its limit than it looks

An existing 42U rack holds six servers measuring 320 W each at the wall, two switches at 150 W each, and a KVM at 50 W. Everything is dual-corded: PSU A to PDU A, PSU B to PDU B, and each PDU is fed by its own 30 A, 208 V single-phase circuit.

1,024 words, about 5 min