mysqldump: Got error: 145: Table './dbname/tablename' is marked as crashed and should be repaired when using LOCK TABLES

If you get this error message while backing up mysql database with mysqldump, you can fix it simply using a command.
# myisamchk -r /var/lib/mysql/dbname/tablename.MYI
- recovering (with sort) MyISAM-table '/var/lib/mysql/dbname/tablename.MYI'
Data records: 4301
- Fixing index 1
Found block that points outside data file at 2051036
Found block that points outside data file at 2051040



Here is myisamchk is the utility tool that we need to use and "/var/lib/mysql/dbname/tablename.MYI" is the physical path of the table.

Hope this will help you to solve your problem.