通過LVM邏輯卷實現MySQL備份及還原（幾乎熱備）：
前提：
1、數據文件要在邏輯捲上；
2、此邏輯卷所在卷組必須有足夠的空間使用快照卷；
3、數據文件和事務日誌要在同一個邏輯捲上；
步驟：
1、打開會話，施加讀鎖，鎖定所有表；
mysql> FLUSH TABLES WITH READ LOCK; #刷新表並對錶施加讀鎖
mysql> FLUSH LOGS; #滾動日誌
2、通過另一個終端，保存二進制日誌文件及相關位置信息；
[root@lamp ~]# mysql -uroot -p -e 'SHOW MASTER STATUS\G' > /path/to/master.info
#不登錄mysql客戶端直接查看位置狀態，並保存位置信息到相應目錄
3、創建快照卷
[root@lamp ~]# lvcreate -L SIZE -s -p r -n LV_NAME /path/to/source_lv
#創建快照卷，-s:指定爲所創建的是快照卷s=snapshot快照; -p:指定權限p=permission許可；
r:讀權限;-n:指定快照名稱；LV_NAME:快照名稱;/path/to/source_lv:針對哪個邏輯卷目錄
路徑做快照;-L:指定快照卷大小。
4、釋放鎖
mysql> UNLOCK TABLES; #釋放鎖
5、掛載快照卷，並備份；
mount /dev/myvg/mydata-snap /mnt -o ro #掛載快照卷至/mnt目錄，只讀掛載
cp -a ./* /backup/full-backup-2017-06-06/ #掛載後把數據複製到備份目錄， -a:表示
複製文件的所有屬性及內容，保留源文件的所有屬性及權限
6、刪除快照卷
umount /mnt #備份完後卸載快照卷掛載的目錄
lvremove --force /dev/myvg/mydata-snap #強制移除快照卷
rm -rf mysql-bin.* #把備份目錄中的日誌文件刪除掉，節省空間
7、增量備份二進制日誌
mysqlbinlog --start-datetime='2017-06-06 10:11:02' mysql-bin.000005 mysql-bin.000006 > /backup/incremental-`date +%F-%H-%M-%S`.sql #備份二進制日誌，如果增量備份的二進制日誌
含有2個或以上的日誌文件，需要通過指定開始時間點來備份。
實例：通過實際操作，實現lvm邏輯卷快照備份及恢復mysql操作；
首先打開mysql客戶端：
[root@lamp ~]# mysql #打開mysql客戶端
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.5.28-log Source distribution
Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> FLUSH TABLES WITH READ LOCK; #首先刷新表並施加讀鎖
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH LOGS; #滾動日誌
Query OK, 0 rows affected (0.06 sec)
mysql> SHOW MASTER STATUS; #查看二進制日誌位置狀態
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000005 | 107 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
不要退出或關閉此mysql客戶端，重新打開一個服務器終端，執行位置信息的保存；
[root@lamp ~]# mkdir /backup #新建一個備份目錄
[root@lamp ~]# mysql -e 'SHOW MASTER STATUS\G;' > /backup/master-`date +%F`.info #不登錄mysql客戶端，直接通過mysql -e直接編輯數據庫，把查看二進制日誌位置狀態保存至備份目錄下
[root@lamp ~]# ls /backup/
master-2017-06-06.info
對mysql數據目錄執行快照（所以說通過邏輯卷備份數據庫，前提必須是數據文件存放在邏輯捲上）
[root@lamp ~]# lvcreate -L 50M -s -p r -n mydata-snap /dev/myvg/mydata #對/dev/myvg/mydata邏輯卷做快照，大小爲50M，-s:表示snapshot快照，-p:指定權限permission
r:讀的權限read,-n:指定快照卷的名稱。
Rounding up size to full physical extent 52.00 MiB
Logical volume "mydata-snap" created
[root@lamp ~]# lvs #查看邏輯卷，剛新建的快照邏輯卷
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
mydata myvg owi-ao 10.00g
mydata-snap myvg sri-a- 52.00m mydata 0.02
[root@lamp ~]# mount #查看掛載相關信息
/dev/sda7 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
/dev/sda3 on /home type ext4 (rw)
/dev/sda5 on /tmp type ext4 (rw)
/dev/sda2 on /usr/local type ext4 (rw)
/dev/mapper/myvg-mydata on /mydata type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
執行完快照後，即可解鎖表；
mysql> UNLOCK TABLES; #解鎖
Query OK, 0 rows affected (0.00 sec)
對快照進行掛載並備份；
[root@lamp ~]# mount /dev/myvg/mydata-snap /mnt -o ro #以只讀方式掛載剛做的快照卷
[root@lamp ~]# cd /mnt #進入掛載目錄
[root@lamp mnt]# ls
data lost+found
[root@lamp mnt]# cd data/
[root@lamp data]# ls
hellodb ib_logfile1 lamp.pid mysql-bin.000001 mysql-bin.000004 performance_schema testdb ibdata1 jiaowu mydb mysql-bin.000002 mysql-bin.000005 stu
ib_logfile0 lamp.err mysql mysql-bin.000003 mysql-bin.index test
[root@lamp data]# mkdir /backup/full-backup-`date +%F` #創建備份目錄並以時間格式命名
[root@lamp data]# cp -a ./* /backup/full-backup-2017-06-06/ #-a:複製當前目錄的所有內容及其權限屬性到備份的目錄
[root@lamp data]# cd
[root@lamp ~]# umount /mnt #卸載掛載的目錄/mnt
[root@lamp ~]# lvremove --force /dev/myvg/mydata-snap #移除剛纔創建的快照卷--force強制性
Logical volume "mydata-snap" successfully removed
[root@lamp ~]# cd /backup/full-backup-2017-06-06/
[root@lamp full-backup-2017-06-06]# ls
hellodb ib_logfile1 lamp.pid mysql-bin.000001 mysql-bin.000004 performance_schema testdb ibdata1 jiaowu mydb mysql-bin.000002 mysql-bin.000005 stu
ib_logfile0 lamp.err mysql mysql-bin.000003 mysql-bin.index test
[root@lamp full-backup-2017-06-06]# rm -rf mysql-bin.* #刪除相關的二進制日誌文件以便節省空間
[root@lamp full-backup-2017-06-06]# ls
hellodb ib_logfile0 jiaowu lamp.pid mysql stu testdb
ibdata1 ib_logfile1 lamp.err mydb performance_schema test
root@lamp ~]# cd /mydata/data
[root@lamp data]# ls
hellodb ib_logfile1 lamp.pid mysql-bin.000001 mysql-bin.000004 performance_schema testdb ibdata1 jiaowu mydb mysql-bin.000002 mysql-bin.000005 stu
ib_logfile0 lamp.err mysql mysql-bin.000003 mysql-bin.index test
[root@lamp data]# cat /backup/master-2017-06-06.info
*************************** 1. row ***************************
File: mysql-bin.000005 #記錄的二進制日誌文件
Position: 107 #二進制日誌的位置
Binlog_Do_DB:
Binlog_Ignore_DB:
mysql> FLUSH LOGS; #滾動日誌
Query OK, 0 rows affected (0.01 sec)
mysql> USE jiaowu
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> INSERT INTO tutors(Tname) VALUES ('stu0003'); #往表tutors中插入數據,字段Tname 值stu0003
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO tutors(Tname) VALUES ('stu0004'); #往表tutors中插入數據,字段Tname 值stu0004
Query OK, 1 row affected (0.00 sec)
mysql> SHOW MASTER STATUS; #查看此時二進制日誌的位置狀態信息
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000006 | 575 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
mysql> \q
Bye
[root@lamp data]# mysqlbinlog --start-datetime='2017-06-06 10:11:02' mysql-bin.000005 mysql-bin.000006 > /backup/incremental-`date +%F-%H-%M-%S`.sql #導出二進制日誌文件bin.000005和bin.000006時間點從2017-06-06 10:11:02開始後的內容
[root@lamp data]# ls /backup/incremental-2017-06-06-17-01-41.sql
/backup/incremental-2017-06-06-17-01-41.sql
[root@lamp data]# service mysqld stop #停止mysqld進程
Shutting down MySQL.. [ OK ]
[root@lamp data]# rm -rf ./* #模擬mysql數據庫數據目錄內容丟失（手動刪除）
[root@lamp data]# ls #目錄中的內容全部刪除，查看顯示爲空
[root@lamp data]# cp -a /backup/full-backup-2017-06-06/* ./ #複製之前快照卷備份的內容至當前數據目錄，-a:複製文件的內容及權限屬性。
[root@lamp data]# ll #確保所有文件的屬主爲mysql用戶
total 28712
drwx------. 2 mysql mysql 4096 Jun 2 15:30 hellodb
-rw-rw----. 1 mysql mysql 18874368 Jun 5 14:00 ibdata1
-rw-rw----. 1 mysql mysql 5242880 Jun 5 14:00 ib_logfile0
-rw-rw----. 1 mysql mysql 5242880 Jun 2 15:28 ib_logfile1
drwx------. 2 mysql mysql 4096 Jun 5 14:00 jiaowu
-rw-rw----. 1 mysql root 1853 Jun 2 15:28 lamp.err
-rw-rw----. 1 mysql mysql 6 Jun 2 15:28 lamp.pid
drwx------. 2 mysql mysql 4096 Jun 2 15:30 mydb
drwx------. 2 mysql root 4096 Jun 2 15:30 mysql
drwx------. 2 mysql mysql 4096 Jun 2 15:28 performance_schema
drwx------. 2 mysql mysql 4096 Jun 2 15:30 stu
drwx------. 2 mysql root 4096 Jun 2 15:28 test
drwx------. 2 mysql mysql 4096 Jun 2 15:30 testdb
[root@lamp data]# service mysqld start #開啓mysqld進程
Starting MySQL [ OK ]
[root@lamp data]# mysql -uroot -p #登錄mysql客戶端
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.28-log Source distribution
Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> USE jiaowu
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> SELECT * FROM tutors; #查詢tutors表的內容（此時後插入的2行數據沒有）
+-----+--------------+--------+------+
| TID | Tname | Gender | Age |
+-----+--------------+--------+------+
| 1 | HongQigong | M | 93 |
| 2 | HuangYaoshi | M | 63 |
| 3 | Miejueshitai | F | 72 |
| 4 | OuYangfeng | M | 76 |
| 5 | YiDeng | M | 90 |
| 6 | YuCanghai | M | 56 |
| 7 | Jinlunfawang | M | 67 |
| 8 | HuYidao | M | 42 |
| 9 | NingZhongze | F | 49 |
+-----+--------------+--------+------+
9 rows in set (0.00 sec)
mysql> SET sql_log_bin=0; #導入二進制日誌前，先關閉日誌記錄功能0爲關閉，1爲打開
Query OK, 0 rows affected (0.00 sec)
mysql> SOURCE /backup/incremental-2017-06-06-17-01-41.sql #導入備份的二進制日誌數據
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT * FROM tutors; #再次查詢tutors表的內容，此時後插入的2行數據已經生成
+-----+--------------+--------+------+
| TID | Tname | Gender | Age |
+-----+--------------+--------+------+
| 1 | HongQigong | M | 93 |
| 2 | HuangYaoshi | M | 63 |
| 3 | Miejueshitai | F | 72 |
| 4 | OuYangfeng | M | 76 |
| 5 | YiDeng | M | 90 |
| 6 | YuCanghai | M | 56 |
| 7 | Jinlunfawang | M | 67 |
| 8 | HuYidao | M | 42 |
| 9 | NingZhongze | F | 49 |
| 10 | stu0003 | M | NULL |
| 11 | stu0004 | M | NULL |
+-----+--------------+--------+------+
11 rows in set (0.00 sec)
mysql> SET sql_log_bin=1; #二進制日誌導入後再打開二進制日誌記錄功能
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW MASTER STATUS; #查看此時的二進制日誌位置狀態信息
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 | 107 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
至此通過lvm邏輯卷和二進制cp功能實現了mysql數據庫備份和還原。