If we find that our VPS server is abnormal, generally we can analyze it from the server logs to see if there is an IP source that does not follow the "rules". For example, we can use server log analysis tools: ngxtop and GoAccess to analyze the IP source, number of connections, error requests, browsers, traffic bandwidth, etc. in the statistical logs.
I don’t know if I used a VPS host with a high configuration before, or if there is a problem with the performance of the newly moved Alibaba Cloud Hong Kong VPS host. In short, every time I dig the site at night, the host becomes unstable and the system load suddenly becomes high. suddenly low. Using server log analysis tools: ngxtop and GoAccess, you can also find out that some IPs are constantly scanning server ports and WP background.
Regarding the problem of the Linux disk being full, I have encountered it before when using the WDCP panel because the website log was enabled in the background of the panel, but the log was not deleted regularly. In the long run, the disk space of the VPS host was filled up with logs. When the disk space reaches 100%, some inexplicable errors will occur on the website, such as being unable to log in to the background, unable to comment, and the page is blank, etc.
