基于逻辑卷LVM的MySQL、mariadb数据库备份还原详细实现

前提是数据库的数据是放在逻辑卷上的；数据库数据和日志分开存放；正常情况下数据和日志是放在两个独立的磁盘上，如果是raid的话，那么就无所谓了。

创建分区：

        [root@mysql ~]$fdisk /dev/sda        Command (m for help): n        All primary partitions are in use        Adding logical partition 6        First sector (153098240-419430399, default 153098240):         Using default value 153098240        Last sector, +sectors or +size{K,M,G} (153098240-419430399, default 419430399): +10G        Partition 6 of type Linux and of size 10 GiB is set        Command (m for help): t        Partition number (1-6, default 6): 6        Hex code (type L to list all codes): 8e        Changed type of partition 'Linux' to 'Linux LVM'        Command (m for help): w        The partition table has been altered!        Calling ioctl() to re-read partition table.        WARNING: Re-reading the partition table failed with error 16: Device or resource busy.        The kernel still uses the old table. The new table will be used at        the next reboot or after you run partprobe(8) or kpartx(8)        Syncing disks.        [root@mysql ~]$partprobe         Warning: Unable to open /dev/sr0 read-write (Read-only file system).  /dev/sr0 has been opened read-only.        [root@mysql ~]$lsblk        NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT        sda      8:0    0  200G  0 disk         ├─sda1   8:1    0    1G  0 part /boot        ├─sda2   8:2    0   50G  0 part /        ├─sda3   8:3    0   20G  0 part /app        ├─sda4   8:4    0  512B  0 part         ├─sda5   8:5    0    2G  0 part [SWAP]        └─sda6   8:6    0   10G  0 part         sr0     11:0    1  8.1G  0 rom          loop0    7:0    0  8.1G  1 loop /mnt/cdrom

创建PV，vg，lv：

加入PV、VG和LV；[root@mysql ~]$pvcreate /dev/sda6  Physical volume "/dev/sda6" successfully created.[root@mysql ~]$pvs  PV         VG Fmt  Attr PSize  PFree   /dev/sda6     lvm2 ---  10.00g 10.00g[root@mysql ~]$vgcreate vg0 /dev/sda6  Volume group "vg0" successfully created[root@mysql ~]$vgs  VG  #PV #LV #SN Attr   VSize   VFree    vg0   1   0   0 wz--n- <10.00g <10.00g[root@mysql ~]$vgdisplay   --- Volume group ---  VG Name               vg0  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  1  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                0  Open LV               0  Max PV                0  Cur PV                1  Act PV                1  VG Size               <10.00 GiB  PE Size               4.00 MiB  Total PE              2559  Alloc PE / Size       0 / 0     Free  PE / Size       2559 / <10.00 GiB  VG UUID               fuGxOy-IVrf-SnWd-C0ie-eb9O-LIWz-sMx17T[root@mysql ~]$pvs  PV         VG  Fmt  Attr PSize   PFree    /dev/sda6  vg0 lvm2 a--  <10.00g <10.00g创建的LV，剩余的空间用于放置快照数据；[root@mysql ~]$lvcreate -n mysqldata -L 2G vg0   Logical volume "mysqldata" created.[root@mysql ~]$lvcreate -n binlogs -L 3G vg0   Logical volume "binlogs" created.[root@mysql ~]$pvs  PV         VG  Fmt  Attr PSize   PFree   /dev/sda6  vg0 lvm2 a--  <10.00g <5.00g[root@mysql ~]$vgs  VG  #PV #LV #SN Attr   VSize   VFree   vg0   1   2   0 wz--n- <10.00g <5.00g格式化文件系统：[root@mysql ~]$mkfs.xfs /dev/vg0/mysqldata meta-data=/dev/vg0/mysqldata     isize=512    agcount=4, agsize=131072 blks         =                       sectsz=512   attr=2, projid32bit=1         =                       crc=1        finobt=0, sparse=0data     =                       bsize=4096   blocks=524288, imaxpct=25         =                       sunit=0      swidth=0 blksnaming   =version 2              bsize=4096   ascii-ci=0 ftype=1log      =internal log           bsize=4096   blocks=2560, version=2         =                       sectsz=512   sunit=0 blks, lazy-count=1realtime =none                   extsz=4096   blocks=0, rtextents=0[root@mysql ~]$mkfs.xfs /dev/vg0/binlogs meta-data=/dev/vg0/binlogs       isize=512    agcount=4, agsize=196608 blks         =                       sectsz=512   attr=2, projid32bit=1         =                       crc=1        finobt=0, sparse=0data     =                       bsize=4096   blocks=786432, imaxpct=25         =                       sunit=0      swidth=0 blksnaming   =version 2              bsize=4096   ascii-ci=0 ftype=1log      =internal log           bsize=4096   blocks=2560, version=2         =                       sectsz=512   sunit=0 blks, lazy-count=1realtime =none                   extsz=4096   blocks=0, rtextents=0[root@mysql ~]$[root@mysql ~]$blkid/dev/sda1: UUID="07deeea1-2041-4e34-98ba-2529dfb30c32" TYPE="xfs" /dev/sda2: UUID="a7595dc1-7958-4728-954b-e8dcfb6bca3c" TYPE="xfs" /dev/sda3: UUID="3c26d76c-a6a6-4c40-90fd-c2a38520b674" TYPE="xfs" /dev/sda5: UUID="7f480b58-5216-4561-a933-43766aa0ff05" TYPE="swap" /dev/sda6: UUID="1dGdT7-kPEX-pLCH-id8y-0269-244Y-3hiJcW" TYPE="LVM2_member" /dev/sr0: UUID="2017-09-06-10-53-42-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos" /dev/loop0: UUID="2017-09-06-10-53-42-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos" /dev/mapper/vg0-mysqldata: UUID="6f9f0f27-dba5-4479-adb6-532362d80d38" TYPE="xfs" /dev/mapper/vg0-binlogs: UUID="150de97a-7a76-465e-9d6a-1357600fa152" TYPE="xfs"

提供数据目录，挂载：

[root@mysql ~]$mkdir /data/{mysqldata,binlogs} -pvmkdir: created directory '/data'mkdir: created directory '/data/mysqldata'mkdir: created directory '/data/binlogs'[root@mysql ~]$ll /data/total 0drwxr-xr-x 2 root root 6 Feb 25 10:07 binlogsdrwxr-xr-x 2 root root 6 Feb 25 10:07 mysqldata[root@mysql ~]$vim /etc/fstab...UUID=6f9f0f27-dba5-4479-adb6-532362d80d38   /data/mysqldata/    xfs     defaults    0   0UUID=150de97a-7a76-465e-9d6a-1357600fa152   /data/binlogs/      xfs     defaults    0   0[root@mysql ~]$mount -a[root@mysql ~]$df -PhFilesystem                 Size  Used Avail Use% Mounted on/dev/sda2                   50G  3.5G   47G   7% /devtmpfs                   474M     0  474M   0% /devtmpfs                      489M     0  489M   0% /dev/shmtmpfs                      489M  7.2M  482M   2% /runtmpfs                      489M     0  489M   0% /sys/fs/cgroup/dev/sda3                   20G   33M   20G   1% /app/dev/loop0                 8.1G  8.1G     0 100% /mnt/cdrom/dev/sda1                 1014M  158M  857M  16% /boottmpfs                       98M     0   98M   0% /run/user/0/dev/mapper/vg0-mysqldata  2.0G   33M  2.0G   2% /data/mysqldata/dev/mapper/vg0-binlogs    3.0G   33M  3.0G   2% /data/binlogs[root@mysql ~]$ll /data/total 0drwxr-xr-x 2 root root 6 Feb 25 10:05 binlogsdrwxr-xr-x 2 root root 6 Feb 25 10:05 mysqldata[root@mysql ~]$chown -R mysql.mysql /data/[root@mysql ~]$ll /data/total 0drwxr-xr-x 2 mysql mysql 6 Feb 25 10:07 binlogsdrwxr-xr-x 2 mysql mysql 6 Feb 25 10:07 mysqldata[root@mysql ~]$ll /data/ -ddrwxr-xr-x 4 mysql mysql 38 Feb 25 10:07 /data/

提供数据：

vim /etc/my.cnf[mysqld]#datadir=/var/lib/mysqldatadir=/data/mysqldata/socket=/var/lib/mysql/mysql.sock# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0log_bin=/data/binlogs/mysql-bininnodb_file_per_table[root@mysql ~]$ll /data/ -ddrwxr-xr-x 4 mysql mysql 38 Feb 25 10:07 /data/[root@mysql ~]$ll /data/total 0drwxr-xr-x 2 mysql mysql 101 Feb 25 10:17 binlogsdrwxr-xr-x 5 mysql mysql 159 Feb 25 10:17 mysqldata[root@mysql ~]$ll /data/mysqldata/total 36892-rw-rw---- 1 mysql mysql    16384 Feb 25 10:17 aria_log.00000001-rw-rw---- 1 mysql mysql       52 Feb 25 10:17 aria_log_control-rw-rw---- 1 mysql mysql 18874368 Feb 25 10:17 ibdata1-rw-rw---- 1 mysql mysql  5242880 Feb 25 10:17 ib_logfile0-rw-rw---- 1 mysql mysql  5242880 Feb 25 10:17 ib_logfile1drwx------ 2 mysql mysql     4096 Feb 25 10:17 mysqldrwx------ 2 mysql mysql     4096 Feb 25 10:17 performance_schemadrwx------ 2 mysql mysql        6 Feb 25 10:17 test[root@mysql ~]$ll /data/binlogs/total 1056-rw-rw---- 1 mysql mysql   30331 Feb 25 10:17 mysql-bin.000001-rw-rw---- 1 mysql mysql 1038814 Feb 25 10:17 mysql-bin.000002-rw-rw---- 1 mysql mysql     245 Feb 25 10:17 mysql-bin.000003-rw-rw---- 1 mysql mysql      93 Feb 25 10:17 mysql-bin.index[root@mysql ~]$mysql < hellodb_InnoDB.sqlMariaDB [(none)]> show databases;+--------------------+| Database           |+--------------------+| information_schema || hellodb            || mysql              || performance_schema || test               |+--------------------+5 rows in set (0.00 sec)MariaDB [(none)]> show binary logs;+------------------+-----------+| Log_name         | File_size |+------------------+-----------+| mysql-bin.000001 |     30331 || mysql-bin.000002 |   1038814 || mysql-bin.000003 |      7655 |+------------------+-----------+3 rows in set (0.00 sec)开始备份之前，需要先加全局读锁；MariaDB [(none)]> flush tables with read lock;Query OK, 0 rows affected (0.00 sec)

刷新日志，记录二进制日志的位置：

MariaDB [(none)]> flush logs;Query OK, 0 rows affected (0.01 sec)MariaDB [(none)]> show binary logs;+------------------+-----------+| Log_name         | File_size |+------------------+-----------+| mysql-bin.000001 |     30331 || mysql-bin.000002 |   1038814 || mysql-bin.000003 |      7698 || mysql-bin.000004 |       245 |+------------------+-----------+4 rows in set (0.00 sec)记录二进制日志的位置：[root@mysql ~]$mysql -e 'show binary logs'+------------------+-----------+| Log_name         | File_size |+------------------+-----------+| mysql-bin.000001 |     30331 || mysql-bin.000002 |   1038814 || mysql-bin.000003 |      7698 || mysql-bin.000004 |       245 |+------------------+-----------+[root@mysql ~]$mysql -e 'show binary logs' > pos.log

使用lv创建数据库快照：

[root@mysql ~]$lvs  LV        VG  Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert  binlogs   vg0 -wi-ao---- 3.00g                                                      mysqldata vg0 -wi-ao---- 2.00g      [root@mysql ~]$lvcreate -n mysqldata-snapshot -s -p r -L 2G /dev/vg0/mysqldata  Using default stripesize 64.00 KiB.  Logical volume "mysqldata-snapshot" created.[root@mysql ~]$lvs  LV                 VG  Attr       LSize Pool Origin    Data%  Meta%  Move Log Cpy%Sync Convert  binlogs            vg0 -wi-ao---- 3.00g                                                         mysqldata          vg0 owi-aos--- 2.00g                                                         mysqldata-snapshot vg0 sri-a-s--- 2.00g      mysqldata 0.00             [root@mysql ~]$lvdisplay --- Logical volume ---  LV Path                /dev/vg0/mysqldata-snapshot  LV Name                mysqldata-snapshot  VG Name                vg0  LV UUID                oQZBaU-IEld-M2wc-IQHo-A8nH-e53J-SrRujn  LV Write Access        read only  LV Creation host, time mysql, 2018-02-25 10:25:18 +0800  LV snapshot status     active destination for mysqldata  LV Status              available  # open                 0  LV Size                2.00 GiB  Current LE             512  COW-table size         2.00 GiB  COW-table LE           512  Allocated to snapshot  0.00%  Snapshot chunk size    4.00 KiB  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     8192  Block device           253:4当做完快照后，那么就可以继续让用户访问数据库了；MariaDB [(none)]> unlock tables;Query OK, 0 rows affected (0.00 sec)修改和破坏操作；MariaDB [(none)]> delete from hellodb.students;Query OK, 25 rows affected (0.01 sec)

挂载快照，将数据备份出来；    直接挂载是挂载不了的，因为两个设备文件的UUID是一样的；    /dev/mapper/vg0-mysqldata: UUID="6f9f0f27-dba5-4479-adb6-532362d80d38" TYPE="xfs"     /dev/mapper/vg0-binlogs: UUID="150de97a-7a76-465e-9d6a-1357600fa152" TYPE="xfs"     /dev/mapper/vg0-mysqldata--snapshot: UUID="6f9f0f27-dba5-4479-adb6-532362d80d38" TYPE="xfs"[root@mysql ~]$man mountnouuid Don''t check for double mounted file systems using the file system uuid.  This is useful to mount LVM snapshot vol‐              umes, and often used in combination with "norecovery" for mounting read-only snapshots.[root@mysql ~]$mkdir /mnt/snap[root@mysql ~]$mount -o nouuid,norecovery /dev/vg0/mysqldata-snapshot /mnt/snap/mount: /dev/mapper/vg0-mysqldata--snapshot is write-protected, mounting read-only[root@mysql ~]$df -PhFilesystem                           Size  Used Avail Use% Mounted on/dev/sda2                             50G  3.4G   47G   7% /devtmpfs                             474M     0  474M   0% /devtmpfs                                489M     0  489M   0% /dev/shmtmpfs                                489M  7.2M  482M   2% /runtmpfs                                489M     0  489M   0% /sys/fs/cgroup/dev/sda3                             20G   33M   20G   1% /app/dev/loop0                           8.1G  8.1G     0 100% /mnt/cdrom/dev/sda1                           1014M  158M  857M  16% /boottmpfs                                 98M     0   98M   0% /run/user/0/dev/mapper/vg0-mysqldata            2.0G   63M  2.0G   4% /data/mysqldata/dev/mapper/vg0-binlogs              3.0G   34M  3.0G   2% /data/binlogs/dev/mapper/vg0-mysqldata--snapshot  2.0G   31M  2.0G   2% /mnt/snap建议打包，放在远程存储上；有些企业使用磁带机进行备份；[root@mysql ~]$mkdir /backups[root@mysql ~]$cd /mnt/snap/[root@mysql snap]$lsaria_log.00000001  aria_log_control  hellodb  ibdata1  ib_logfile0  ib_logfile1  mysql  performance_schema  test[root@mysql snap]$cp -a /mnt/snap/* /backups/[root@mysql snap]$ll /backups/ -htotal 29M-rw-rw---- 1 mysql mysql  16K Feb 25 10:17 aria_log.00000001-rw-rw---- 1 mysql mysql   52 Feb 25 10:17 aria_log_controldrwx------ 2 mysql mysql  272 Feb 25 10:19 hellodb-rw-rw---- 1 mysql mysql  18M Feb 25 10:19 ibdata1-rw-rw---- 1 mysql mysql 5.0M Feb 25 10:19 ib_logfile0-rw-rw---- 1 mysql mysql 5.0M Feb 25 10:17 ib_logfile1drwx------ 2 mysql mysql 4.0K Feb 25 10:17 mysqldrwx------ 2 mysql mysql 4.0K Feb 25 10:17 performance_schemadrwx------ 2 mysql mysql    6 Feb 25 10:17 test删除快照，否则影响性能；[root@mysql snap]$umount /mnt/snap/umount: /mnt/snap: target is busy.        (In some cases useful info about processes that use         the device is found by lsof(8) or fuser(1))[root@mysql snap]$cd[root@mysql ~]$umount /mnt/snap/[root@mysql ~]$lvremove /dev/vg0/mysqldata-snapshot Do you really want to remove active logical volume vg0/mysqldata-snapshot? [y/n]: y  Logical volume "mysqldata-snapshot" successfully removed

数据库出现故障的模拟：    需要停止数据库服务；    [root@mysql ~]$systemctl stop mariadb    [root@mysql ~]$rm -rf /data/mysqldata/*数据库的还原操作：    [root@mysql ~]$cp -a /backups/* /data/mysqldata/    [root@mysql ~]$systemctl start mariadb    MariaDB [(none)]> show databases;    +--------------------+    | Database           |    +--------------------+    | information_schema |    | hellodb            |    | mysql              |    | performance_schema |    | test               |    +--------------------+MariaDB [(none)]> show master logs;+------------------+-----------+| Log_name         | File_size |+------------------+-----------+| mysql-bin.000001 |     30331 || mysql-bin.000002 |   1038814 || mysql-bin.000003 |      7698 || mysql-bin.000004 |       442 || mysql-bin.000005 |       245 |+------------------+-----------+5 rows in set (0.00 sec)此时只是恢复了一部分的数据，但是不是最新的，要想恢复至最新状态，那么需要使用mysql-bin.000004  245和mysql-bin.000005   245之间的二进制完成恢复；[root@mysql ~]$lsall_2018-02-24_21:46:13.sql  anaconda-ks.cfg  hellodb_InnoDB.sql    mariadb-bin.000010  r7.shall.sql                      binlog.sql       initial-setup-ks.cfg  pos.log[root@mysql ~]$less pos.log Log_name        File_sizemysql-bin.000001        30331mysql-bin.000002        1038814mysql-bin.000003        7698mysql-bin.000004        245[root@mysql ~]$cd /data/binlogs/[root@mysql binlogs]$lsmysql-bin.000001  mysql-bin.000002  mysql-bin.000003  mysql-bin.000004  mysql-bin.000005  mysql-bin.index[root@mysql binlogs]$cp -a mysql-bin.00000{4,5} ~MariaDB [(none)]> flush tables with read lock;Query OK, 0 rows affected (0.00 sec)[root@mysql ~]$mysqlbinlog --start-position=245 mysql-bin.000004 > binlog.sql [root@mysql ~]$mysqlbinlog mysql-bin.000005 >> binlog.sqlMariaDB [(none)]> set sql_log_bin=0;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> unlock tables;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> source binlog.sql此时发现students表是空的；MariaDB [(none)]> select * from hellodb.students;

注意：    MySQLdump 的备份是温备；    他的效率也不是特别的高，因为他的备份是相当于对MySQL数据库进行的查询操作的结果；    如果是T级别的数据库，那么查询备份就需要大量的时间。