MySQL更改默认的数据文档存储目录

MySQL默认的数据文档存储目录为/var/lib/mysql。假如要把MySQL目录移到/home/data下需要进行下面几步：

1、创建目录

cd /opt && mkdir data

2、把MySQL服务进程停掉

mysqladmin -u root -p shutdown .. 或者 service mysqld stop

3、把/var/lib/mysql整个目录移到/home/data
mv /var/lib/mysql/* /opt/data/
这样就把MySQL的数据文档移动到了/home/data/下 。

4、找到my.cnf配置文档 

假如/etc/目录下没有my.cnf配置文档，请到/usr/share/mysql/下找到*.cnf文档，拷贝其中一个到/etc/并改名为my.cnf)中。
命令如下：
[root@test1 mysql]# cp /usr/share/mysql/my-medium.cnf /etc/my.cnf

5、编辑MySQL的配置文档/etc/my.cnf 
为确保MySQL能够正常工作，需要指明mysql.sock文档的产生位置。修改socket=/var/lib/mysql/mysql.sock一行中等号右边的值为：/home/mysql/mysql.sock 。操作如下： .
vi my.cnf (用vi工具编辑my.cnf文档，找到下列数据修改之，有的版本上是有的，就不用改了) .
# The MySQL server
[mysqld]
port = 3306
#socket = /var/lib/mysql/mysql.sock(原内容，为了更稳妥用“#”注释此行)
socket = /opt/data/mysql/mysql.sock (加上此行) .

6、修改MySQL启动脚本/etc/init.d/mysql   
最后，需要修改MySQL启动脚本/etc/init.d/mysql，把其中datadir=/var/lib/mysql一行中，等号右边的路径改成您现在的实际存放路径：home/data/mysql。
[root@test1 etc]# vi /etc/init.d/mysql
#datadir=/var/lib/mysql (注释此行) 。
datadir=/opt/data/mysql (加上此行) ..

7、重新启动MySQL服务

/etc/init.d/mysql start ... 或者 service mysqld start

8、配置文件示例 

[root@test1 etc]# more /etc/my.cnf
# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# MySQL programs look for option files in a set of
# locations which depend on the deployment platform.
# You can copy this option file to one of those
# locations. For information about these locations, see:
# http://dev.mysql.com/doc/mysql/en/option-files.html
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password    = your_password
port        = 3306
#socket        = /var/lib/mysql/mysql.sock
socket        = /opt/data/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[mysqld]
port        = 3306
#socket        = /var/lib/mysql/mysql.sock
socket        = /opt/data/mysql.sock
skip-external-locking
key_buffer_size = 16M
max_allowed_packet = 1M
table_open_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M

# Don‘t listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking

# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin

# binary logging format - mixed recommended
binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id    = 1

# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master‘s port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST=‘125.564.12.1‘, MASTER_PORT=3306,
#    MASTER_USER=‘joe‘, MASTER_PASSWORD=‘secret‘;
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables‘ values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin

# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = /var/lib/mysql
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = /var/lib/mysql
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 16M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 5M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[myisamchk]
key_buffer_size = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

[root@test1 etc]#
[root@test1 etc]#
[root@test1 etc]#
[root@test1 etc]# more /etc/init.d/mysqld
#!/bin/sh
#
# mysqld    This shell script takes care of starting and stopping
#        the MySQL subsystem (mysqld).
#
# chkconfig: - 64 36
# description:    MySQL database server.
# processname: mysqld
# config: /etc/my.cnf
# pidfile: /var/run/mysqld/mysqld.pid

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

exec="/usr/bin/mysqld_safe"
prog="mysqld"

# Set timeouts here so they can be overridden from /etc/sysconfig/mysqld
STARTTIMEOUT=120
STOPTIMEOUT=60

[ -e /etc/sysconfig/$prog ] && . /etc/sysconfig/$prog

lockfile=/var/lock/subsys/$prog

# extract value of a MySQL option from config files
# Usage: get_mysql_option SECTION VARNAME DEFAULT
# result is returned in $result
# We use my_print_defaults which prints all options from multiple files,
# with the more specific ones later; hence take the last match.
get_mysql_option(){
    result=`/usr/bin/my_print_defaults "$1" | sed -n "s/^--$2=//p" | tail -n 1`
    if [ -z "$result" ]; then
        # not found, use default
        result="$3"
    fi
}

#get_mysql_option mysqld datadir "/var/lib/mysql"
get_mysql_option mysqld datadir "/opt/data/mysql"
datadir="$result"
get_mysql_option mysqld socket "$datadir/mysql.sock"
socketfile="$result"
get_mysql_option mysqld_safe log-error "/var/log/mysqld.log"
errlogfile="$result"
get_mysql_option mysqld_safe pid-file "/var/run/mysqld/mysqld.pid"
mypidfile="$result"

start(){
    [ -x $exec ] || exit 5
    # check to see if it‘s already running
    RESPONSE=`/usr/bin/mysqladmin --socket="$socketfile" --user=UNKNOWN_MYSQL_USER ping 2&gt;&1`
    if [ $? = 0 ]; then
    # already running, do nothing
    action $"Starting $prog: " /bin/true
    ret=0
    elif echo "$RESPONSE" | grep -q "Access denied for user"
    then
    # already running, do nothing
    action $"Starting $prog: " /bin/true
    ret=0
    else
        # prepare for start
    touch "$errlogfile"
    chown mysql:mysql "$errlogfile"
    chmod 0640 "$errlogfile"
    [ -x /sbin/restorecon ] && /sbin/restorecon "$errlogfile"
    if [ ! -d "$datadir/mysql" ] ; then
        # First, make sure $datadir is there with correct permissions
        if [ ! -e "$datadir" -a ! -h "$datadir" ]
        then
        mkdir -p "$datadir" || exit 1
        fi
        chown mysql:mysql "$datadir"
        chmod 0755 "$datadir"
        [ -x /sbin/restorecon ] && /sbin/restorecon "$datadir"
        # Now create the database
        action $"Initializing MySQL database: " /usr/bin/mysql_install_db --datadir="$datadir" --user=mysql
        ret=$?
        chown -R mysql:mysql "$datadir"
        if [ $ret -ne 0 ] ; then
        return $ret
        fi
    fi
    chown mysql:mysql "$datadir"
    chmod 0755 "$datadir"
    # Pass all the options determined above, to ensure consistent behavior.
    # In many cases mysqld_safe would arrive at the same conclusions anyway
    # but we need to be sure.  (An exception is that we don‘t force the
    # log-error setting, since this script doesn‘t really depend on that,
    # and some users might prefer to configure logging to syslog.)
    # Note: set --basedir to prevent probes that might trigger SELinux
    # alarms, per bug #547485
    $exec   --datadir="$datadir" --socket="$socketfile" \
        --pid-file="$mypidfile" \
        --basedir=/usr --user=mysql &gt;/dev/null 2&gt;&1 &
    safe_pid=$!
    # Spin for a maximum of N seconds waiting for the server to come up;
    # exit the loop immediately if mysqld_safe process disappears.
    # Rather than assuming we know a valid username, accept an "access
    # denied" response as meaning the server is functioning.
    ret=0
    TIMEOUT="$STARTTIMEOUT"
    while [ $TIMEOUT -gt 0 ]; do
        RESPONSE=`/usr/bin/mysqladmin --socket="$socketfile" --user=UNKNOWN_MYSQL_USER ping 2&gt;&1` && break
        echo "$RESPONSE" | grep -q "Access denied for user" && break
        if ! /bin/kill -0 $safe_pid 2&gt;/dev/null; then
        echo "MySQL Daemon failed to start."
        ret=1
        break
        fi
        sleep 1
        let TIMEOUT=${TIMEOUT}-1
    done
    if [ $TIMEOUT -eq 0 ]; then
        echo "Timeout error occurred trying to start MySQL Daemon."
        ret=1
    fi
    if [ $ret -eq 0 ]; then
        action $"Starting $prog: " /bin/true
        touch $lockfile
    else
        action $"Starting $prog: " /bin/false
    fi
    fi
    return $ret
}

stop(){
    if [ ! -f "$mypidfile" ]; then
        # not running; per LSB standards this is "ok"
        action $"Stopping $prog: " /bin/true
        return 0
    fi
    MYSQLPID=`cat "$mypidfile"`
    if [ -n "$MYSQLPID" ]; then
        /bin/kill "$MYSQLPID" &gt;/dev/null 2&gt;&1
        ret=$?
        if [ $ret -eq 0 ]; then
        TIMEOUT="$STOPTIMEOUT"
        while [ $TIMEOUT -gt 0 ]; do
            /bin/kill -0 "$MYSQLPID" &gt;/dev/null 2&gt;&1 || break
            sleep 1
            let TIMEOUT=${TIMEOUT}-1
        done
        if [ $TIMEOUT -eq 0 ]; then
            echo "Timeout error occurred trying to stop MySQL Daemon."
            ret=1
            action $"Stopping $prog: " /bin/false
        else
            rm -f $lockfile
            rm -f "$socketfile"
            action $"Stopping $prog: " /bin/true
        fi
        else
        action $"Stopping $prog: " /bin/false
        fi
    else
        # failed to read pidfile, probably insufficient permissions
        action $"Stopping $prog: " /bin/false
        ret=4
    fi
    return $ret
}
 
restart(){
    stop
    start
}

condrestart(){
    [ -e $lockfile ] && restart || :
}

# See how we were called.
case "$1" in
  start)
    start
    ;;
  stop)
    stop
    ;;
  status)
    status -p "$mypidfile" $prog
    ;;
  restart)
    restart
    ;;
  condrestart|try-restart)
    condrestart
    ;;
  reload)
    exit 3
    ;;
  force-reload)
    restart
    ;;
  *)
    echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
    exit 2
esac

exit $?

[root@test1 etc]#
[root@test1 etc]# chkconfig --add mysqld
[root@test1 etc]# chkconfig --level mysqld on
[root@test1 etc]#
[root@test1 etc]#