After restoring a backup the server can't start..

restoring

# tar -izxf /var/www/bak/db/2013-11-10-1437_mysql.tar.gz -C /var/www/bak/db_import
# innobackupex --use-memory=1G --apply-log /var/www/bak/db_import
# service mysql stop
# mv /var/lib/mysql /var/lib/mysql-old
# mkdir /var/lib/mysql
# innobackupex --copy-back /var/www/bak/db_import
# chown -R mysql:mysql /var/lib/mysql
# service mysql start

error log

131110 21:24:20 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
2013-11-10 21:24:21 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2013-11-10 21:24:21 6194 [Warning] Using pre 5.5 semantics to load error messages from /opt/mysql/server-5.6/share/english/.
2013-11-10 21:24:21 6194 [Warning] If this is not intended, refer to the documentation for valid usage of --lc-messages-dir and --language parameters.
2013-11-10 21:24:21 6194 [Note] Plugin 'FEDERATED' is disabled.
/usr/local/mysql/bin/mysqld: Table 'mysql.plugin' doesn't exist
2013-11-10 21:24:21 6194 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
2013-11-10 21:24:21 6194 [Note] InnoDB: The InnoDB memory heap is disabled
2013-11-10 21:24:21 6194 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2013-11-10 21:24:21 6194 [Note] InnoDB: Compressed tables use zlib 1.2.3
2013-11-10 21:24:21 6194 [Note] InnoDB: Using Linux native AIO
2013-11-10 21:24:21 6194 [Note] InnoDB: Not using CPU crc32 instructions
2013-11-10 21:24:21 6194 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2013-11-10 21:24:21 6194 [Note] InnoDB: Completed initialization of buffer pool
2013-11-10 21:24:21 6194 [Note] InnoDB: Highest supported file format is Barracuda.
2013-11-10 21:24:22 6194 [Note] InnoDB: 128 rollback segment(s) are active.
2013-11-10 21:24:22 6194 [Note] InnoDB: Waiting for purge to start
2013-11-10 21:24:22 6194 [Note] InnoDB: 5.6.12 started; log sequence number 636992658
2013-11-10 21:24:22 6194 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306
2013-11-10 21:24:22 6194 [Note]   - '127.0.0.1' resolves to '127.0.0.1';
2013-11-10 21:24:22 6194 [Note] Server socket created on IP: '127.0.0.1'.
2013-11-10 21:24:22 6194 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist
131110 21:24:22 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

mysql_upgrade

 /opt/mysql/server-5.6/bin/mysql_upgrade -u root -pxxxxx -P 3308
Warning: Using a password on the command line interface can be insecure.
Looking for 'mysql' as: /opt/mysql/server-5.6/bin/mysql
Looking for 'mysqlcheck' as: /opt/mysql/server-5.6/bin/mysqlcheck
FATAL ERROR: Upgrade failed