Mysql MYISAM table keeps crashing
If OOM triggers the &quot;crashes&quot;, then there is too much running on that machine and/or the processes are using too much ram.
It sounds like you have a mixture of MyISAM and InnoDB tables:
innodb-buffer-pool-size        = 4G  -- change to 3G

That might decrease the frequency of OOMs.
Yes, moving to InnoDB is a good idea for many reasons, including avoiding the need to &quot;repair&quot; that big table.  Caution: That big table may grow to 15GB when switching to InnoDB.