I am facing problem while taking dump of mysql database.
Everytime I am getting error

mysqldump: Got error: 1105: File './megablog_mega/wp_63_postmeta.MYD' not found (Errcode: 24) when using LOCK TABLES
and

mysqldump: Got error: 1017: Can't find file:
> './megablog_mega/wp_63_post2cat.frm' (errno: 24) when using LOCK TABLES

Can anyone please suggest.