Random problems with filesystem corruption.

[Paul Groves]

So I have my own personal web server running Ubuntu 18.04.1 LTS, it has 
two partitions on a 160GB HDD, sda1 is the grub partition and sda2 is 
the root partition.

A few months ago I had a bad superblock error and it wouldn't boot.

I booted to the installer USB and run fsck -y /dev/sda2 and this fixed 
the problem.

Now today, I noticed mysql wouldn't start and that the root partition 
was read only....

So I run fsck as before and bam! the server is working again.

I have tested the hard disk using SMART with the long and short tests 
and cannot find any errors.

Can anyone shed some light on this as I have not seen this before and a 
search online just tells me to do what I have already done.

I am worried the HDD is failing perhaps?

thanks

Paul