CompTIA Server+ (SK0-005)TroubleshootingEasy
A server administrator receives an alert that a critical Windows Server is experiencing extremely high disk I/O wait times, consistently above 90%, despite the CPU and memory utilization being well within normal limits. The server hosts several high-transaction databases. What is the MOST likely cause of this issue?
- ACPU throttling due to overheating
- BMemory leak in a database application
- CDisk subsystem bottleneck
- DInsufficient network bandwidth
Show answer & explanationAnswer & explanation
Correct answer: C. Disk subsystem bottleneck
High disk I/O wait times with normal CPU and memory utilization strongly indicate that the storage subsystem is the bottleneck. Database servers are particularly sensitive to disk performance due to frequent read/write operations.
Why the other options are wrong
- A. CPU throttling would result in high CPU utilization or reduced processing power, which is not indicated here.
- B. A memory leak would typically cause high memory utilization or swapping, not primarily high disk I/O wait times if CPU and memory are normal.
- D. Insufficient network bandwidth would manifest as high network utilization or latency, not primarily high disk I/O wait times.
Disk I/O Bottleneck
A Disk I/O bottleneck occurs when the storage subsystem cannot process read/write requests fast enough, leading to high wait times and reduced application performance.
- Characterized by high disk I/O wait times.
- CPU and memory utilization often remain normal.
- Common in database servers or applications with heavy disk access.
- Can be resolved by faster disks (SSDs), RAID optimization, or increasing disk controllers.
Memory trick: Imagine a server like a highway; if one lane (disk) is jammed, everything slows down.