Randomly the server gets overloaded with queries. Queries are accepted and never executed, thus reaching max_connections limit . This I/O wait in top command reaches up to 90% Couple of restarts (and sometimes vacuum and reindex of my biggest tables) fix it for a while (about a week or so). I suspected full-text indexes going wild, but after i dropping indexes i had same issues again. I found that file system have errors. Can this lead to this kind of behavior ? I am planning downtime to fix the FS errors since this can't be done on mounted file systems.