I had an incident happen not too long ago with a server running mysql. Someone had enabled slow query logging on the server but never bothered to implement a log rotation, so the log files slowly filled up the hard drive over time until the disk became completely full and mysql no longer worked properly. When I went to go investigate, I discovered what the problem was and so I deleted all the slow query log files and disabled slow query logging. This resolved the immediate problem, but about a month later the filesystem on the server spontaneously went read-only. The disk was only at about 18% usage when this happened, so the disk was nowhere near full. I contacted the datacenter to investigate for any possible hardware problems, but they told me the hardware was fine and that it was just filesystem errors.
So my question is, what might have caused this to happen? Could the disk being filled up a month before have caused some kind of filesystem errors that slowly grew worse over time until the filesystem eventually went read-only a month later?
P.S. I am aware that I probably should been paying more attention to the disk usage on the server. I know I could have prevented the disk from ever getting filled up in the first place if I did, which was my mistake. However, I am still curious to know what lead up the filesystem spontenously going read-only a month later. I'd appreciate you guys' feedback on this.
Thanks!