DB Error: Table 'sessions' is marked as crashed and should be repaired

Stack Trace:

File: /var/www/html/lib/pkp/classes/session/SessionDAO.inc.php line 177
Function: DAO->update("DELETE FROM sessions WHERE (last_used < ? AND remember = 0) OR (...", Array(2))

File: /var/www/html/lib/pkp/classes/session/SessionManager.inc.php line 209
Function: SessionDAO->deleteSessionByLastUsed(1778708583, 1776202983)

File: (unknown) line (unknown)
Function: SessionManager->gc(3600)

File: /var/www/html/lib/pkp/classes/session/SessionManager.inc.php line 60
Function: session_start()

File: /var/www/html/lib/pkp/classes/session/SessionManager.inc.php line 130
Function: SessionManager->SessionManager(Object(SessionDAO), Object(Request))

File: /var/www/html/classes/security/Validation.inc.php line 281
Function: SessionManager->getManager()

File: /var/www/html/lib/pkp/classes/core/PKPPageRouter.inc.php line 66
Function: Validation->isLoggedIn()

File: /var/www/html/lib/pkp/classes/core/Dispatcher.inc.php line 117
Function: PKPPageRouter->isCacheable(Object(Request))

File: /var/www/html/lib/pkp/classes/core/PKPApplication.inc.php line 178
Function: Dispatcher->dispatch(Object(Request))

File: /var/www/html/index.php line 64
Function: PKPApplication->execute()