Hi!

Populating my mysql on SL6.1 with biological data I ran into my primary 
SSDs limit and thus tried to move the location to another disk (HD). So 
I sudo cp -R'ed everything from /var/lib/mysql to /data/mysqldata and 
changed the permissions accordingly
drwxr-xr-x. 10 mysql   mysql      4096 Jan 28 12:20 mysqldata
and inside mysqldata
drwx------. 2 mysql mysql      4096 Jan 28 12:20 b2g
-rw-r-----. 1 mysql mysql 178257920 Jan 28 20:50 ibdata1
-rw-r-----. 1 mysql mysql   5242880 Jan 28 20:50 ib_logfile0
-rw-r-----. 1 mysql mysql   5242880 Jan 28 20:50 ib_logfile1
drwx------. 2 mysql mysql      4096 Jan 28 12:20 mysql
drwx------. 2 mysql mysql      4096 Jan 28 12:20 orthotest
Then went on to modify /etc/my.cnf to
[mysqld]
#datadir=/var/lib/mysql
datadir=/data/mysqldata
#socket=/var/lib/mysql/mysql.sock
socket=/data/mysqldata/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
#basedir=/data

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid.

Having stopped the server before doing all this I now started again, but 
it failed to work. less /var/log/mysqld.log says:
120128 21:03:08 mysqld_safe mysqld from pid file 
/var/run/mysqld/mysqld.pid ended
120128 21:09:06 mysqld_safe Starting mysqld daemon with databases from 
/data/mysqldata
120128 21:09:06 [Warning] Can't create test file 
/data/mysqldata/superrechenknecht.lower-test
120128 21:09:06 [Warning] Can't create test file 
/data/mysqldata/superrechenknecht.lower-test
^G/usr/libexec/mysqld: Can't change dir to '/data/mysqldata/' (Errcode: 13)
120128 21:09:06 [ERROR] Aborting

120128 21:09:06 [Note] /usr/libexec/mysqld: Shutdown complete

120128 21:09:06 mysqld_safe mysqld from pid file 
/var/run/mysqld/mysqld.pid ended

Tried to set a symbolic link from /var/lib/mysql -> /data/mysqldata but 
that failed to work as well (actually why can't I change the ownership 
of the link from root:root to mysql:mysql?). Finally reading up on 
SElinux I edited my new mysql directory /data/mysqldata to look the same 
as the original mysql folder:
drwxr-xr-x. mysql   mysql   system_u:object_r:mysqld_db_t:s0 mysqldata
drwxr-xr-x. mysql   mysql   system_u:object_r:mysqld_db_t:s0 mysql_old

and within mysqldata:
drwx------. mysql mysql system_u:object_r:mysqld_db_t:s0 b2g
-rw-r-----. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 ibdata1
-rw-r-----. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 ib_logfile0
-rw-r-----. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 ib_logfile1
drwx------. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 mysql
drwx------. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 orthotest
drwx------. mysql mysql system_u:object_r:mysqld_db_t:s0 sknstuff_insp

However, even that does leads to the same error messages in the log file 
and I am really at a loss. Any help with this would be highly 
appreciated (especially as I need a working db quite urgently).

Tschöö

Philipp