New to Percona - need help starting server

MySQL & MariaDB Other MySQL® Questions
1

I’m running CentOS 6.5 with Percona 5.5 on a server that used to have Server version: 5.6.17 MySQL Community Server (GPL). MySQL was removed and Percona installed. MySQL won’t start. I’ve researched the errors and none of the suggestions helped.

[root@servername init.d]# ./mysql status
ERROR! MySQL (Percona Server) is not running, but lock file (/var/lock/subsys/mysql) exists

[root@servername init.d]# ./mysql start
Starting MySQL (Percona Server)… ERROR! The server quit without updating PID file (/var/lib/mysql/servername.pid).

/var/lib/MySQL/servername.err contains:

140624 15:07:58 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
140624 15:07:58 [Note] Plugin ‘FEDERATED’ is disabled.
140624 15:07:58 InnoDB: The InnoDB memory heap is disabled
140624 15:07:58 InnoDB: Mutexes and rw_locks use GCC atomic builtins
140624 15:07:58 InnoDB: Compressed tables use zlib 1.2.3
140624 15:07:58 InnoDB: Using Linux native AIO
140624 15:07:58 InnoDB: Initializing buffer pool, size = 128.0M
140624 15:07:58 InnoDB: Completed initialization of buffer pool
140624 15:07:58 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 50535
140624 15:07:58 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files…
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer…
InnoDB: Doing recovery: scanned up to log sequence number 1597945
140624 15:07:58 InnoDB: Starting an apply batch of log records to the database…
InnoDB: Progress in percents: 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
140624 15:07:59 InnoDB: Waiting for the background threads to start
140624 15:08:00 Percona XtraDB (http://www.percona.com) 5.5.37-35.1-35.1 started; log sequence number 1597945
140624 15:08:00 [ERROR] /usr/sbin/mysqld: Can’t find file: ‘./mysql/host.frm’ (errno: 13)
140624 15:08:00 [ERROR] Fatal error: Can’t open and lock privilege tables: Can’t find file: ‘./mysql/host.frm’ (errno: 13)
140624 15:08:00 mysqld_safe mysqld from pid file /var/lib/mysql/servername.pid ended

Need help to get this server started. Thanks in advance.

2

140624 15:08:00 [ERROR] /usr/sbin/mysqld: Can’t find file: ‘./mysql/host.frm’ (errno: 13)
140624 15:08:00 [ERROR] Fatal error: Can’t open and lock privilege tables: Can’t find file: ‘./mysql/host.frm’ (errno: 13)

Error 13 means “Permission denied” Check if those two files exist and if they are owned by mysql user and group.

If you moved from 5.6 to 5.5, then that’s a downgrade. Check this link please:

[url]http://dev.mysql.com/doc/refman/5.6/en/downgrading-to-previous-series.html[/url]