Mysqldump: Got error: 1016: Can’t open file (errno: 24) when using LOCK TABLES

Ok so today I had to dump 700mb mysql database. I have tried using standard syntax:

mysqldump -uUSER -pPASS db_name > dump.sql

But I have got the following error:
Mysqldump: Got error: 1016: Can’t open file: ‘./db_name/xxx.frm’ (errno: 24) when using LOCK TABLES

I’ve searched a bit and I have found that solution was to add parameter –lock-tables=false so the final working mysqldump command was like this

mysqldump -uUSER -pPASS db_name --lock-tables=false > dump.sql