在实际的企业当中，各种服务有服务的集群，存储有存储的集群（数据有数据的集群），这里我们使用数据库共享服务+共享存储=一个强壮的集群管理
迁移服务集群的时候，数据的同步是非常重要的
这里的存储我们要单独在一个主机上做，然后把存储共享给server1和server]
[root@server2 ~]# dd if=/dev/sdb of=mbr bs=512 count=1
1+0 records in
1+0 records out
512 bytes (512 B) copied, 0.00133835 s, 383 kB/s
[root@server2 ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 512000 sda1
8 2 20458496 sda2
253 0 19439616 dm-0
253 1 1015808 dm-1
8 16 8388608 sdb
8 17 8387584 sdb1
[root@server2 ~]# dd if=/dev/zero of=/dev/sdb bs=512 count=1
1+0 records in
1+0 records out
512 bytes (512 B) copied, 0.000753261 s, 680 kB/s
[root@server2 ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000340f9
Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 2611 20458496 8e Linux LVM
Disk /dev/mapper/VolGroup-lv_root: 19.9 GB, 19906166784 bytes
255 heads, 63 sectors/track, 2420 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/VolGroup-lv_swap: 1040 MB, 1040187392 bytes
255 heads, 63 sectors/track, 126 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdb: 8589 MB, 8589934592 bytes
64 heads, 32 sectors/track, 8192 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
[root@server2 ~]# partprobe
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sda (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
[root@server2 ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 512000 sda1
8 2 20458496 sda2
253 0 19439616 dm-0
253 1 1015808 dm-1
8 16 8388608 sdb
8 17 8387584 sdb1
[root@server2 ~]# mount /dev/sdb1 /mnt
mount: /dev/sdb1 already mounted or /mnt busy
mount: according to mtab, /dev/sdb1 is already mounted on /mnt分区表的恢复
[root@server2 ~]# dd if=mbr of=/dev/sdb
1+0 records in
1+0 records out
512 bytes (512 B) copied, 0.00112733 s, 454 kB/s
[root@server2 ~]# fdisk -cu /dev/sdb
Command (m for help): p
Disk /dev/sdb: 8589 MB, 8589934592 bytes
64 heads, 32 sectors/track, 8192 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa908f340
Device Boot Start End Blocks Id System
/dev/sdb1 2048 16777215 8387584 83 Linux
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@server2 ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 512000 sda1
8 2 20458496 sda2
253 0 19439616 dm-0
253 1 1015808 dm-1
8 16 8388608 sdb
8 17 8387584 sdb1
[root@server2 ~]# mount /dev/sdb1 /mnt
mount: /dev/sdb1 already mounted or /mnt busy
mount: according to mtab, /dev/sdb1 is already mounted on /mnt
[root@server2 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup-lv_root 19134332 1064932 17097420 6% /
tmpfs 510200 25656 484544 6% /dev/shm
/dev/sda1 495844 33466 436778 8% /boot
/dev/sdb1 8255928 149492 7687060 2% /mnt
[root@server2 ~]# cd /mnt
[root@server2 mnt]# ls
file lost+found
[root@server2 mnt]# rm -rf file
[root@server2 mnt]# cd
[root@server2 ~]# umount /mnt
[root@server2 ~]# fdisk -cu /dev/sdb
Command (m for help): d
Selected partition 1
Command (m for help): p
Disk /dev/sdb: 8589 MB, 8589934592 bytes
64 heads, 32 sectors/track, 8192 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa908f340
Device Boot Start End Blocks Id System
Command (m for help): wq
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@server2 ~]# mkfs.ext4 /dev/sdb
mke2fs 1.41.12 (17-May-2010)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
524288 inodes, 2097152 blocks
104857 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2147483648
64 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 29 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override