Why is it slow to work through ssh?

Question

SSH

I connect to the server via ssh. Everything works fine. but periodically there comes such a period that the server reacts to commands for a long time (from instantly to several seconds). At the same time, the ping to it is 0.8-1.5 milliseconds, there are no losses. How to understand what is the problem?
ps the problem is clearly not in dns. There are other servers nearby, the connection is good with them

Answer 1

Set up constant load monitoring on the server. Perhaps some short periodic loads. Or really - the disk tupit / pours when accessing certain areas.
In addition, the fact that the ping is fast does not mean that there are no problems in the channel. Ping and SSH work slightly on different stack protocols. Somehow they investigated an indescribable case when SSH was dumb as hell. However, everything else was normal. The investigation showed that if you connect to the server via L2TP and go to SSH through the tunnel, then there were no brakes. L2TP works over UDP. The moral was this - the provider had problems on the channel when processing TCP traffic, while UDP and ICMP did not experience any problems.

Answer 2

mb the server is loaded? met similar when load_average > 2 per core