5 places to check first when systems slow down
When the "everything is slow" complaint comes in, check these five places in order instead of guessing.
“The system is slow” is the sentence we hear most, and the one that says least. Slowness usually comes from a bottleneck in a single resource. Looking in the right place turns hours of debate into a few minutes.
1. Disk
The disk is one of the most common causes of slowness. If the CPU looks idle but the system is slow, check the disk queue and latency. A disk that is nearly full, or a backup job sharing the same disk, can slow everything down.
2. Memory
When memory runs out, the system starts swapping to disk and everything slows down at once. Look at swap usage rather than total usage. Tuning operating system parameters can reduce swap use.
3. CPU
A CPU constantly above 90 percent is a real bottleneck. On virtual servers, also measure how long the server waits for CPU time, with metrics like “CPU ready”.
4. Network and DNS
Not everything that opens slowly is a server problem. Slow DNS resolution or dropped packets make an application feel slow.
5. Database
Most applications wait on the database. Slow queries, missing indexes and locks become visible as the number of users grows.
For technical teams: a quick look
# disk latency and queue
iostat -x 5 3
# memory and swap
free -h; vmstat 5 5
These measurements are a snapshot. The real value comes from collecting the same values for weeks and knowing what normal looks like. One of the most important tools for finding slowness is a monitoring application. Our recommendation at Sorgu Teknoloji is to set up Zabbix or an equivalent monitoring environment, so the causes of slowness can be tracked quickly from one place. We can help you with setting up and consulting on a monitoring environment.
As part of Performance and Monitoring, we monitor your systems, measure the bottleneck and fix it for good.