實驗案例一：遷移/home分區
（一）實驗環境
公司原來安裝的RHEL6服務器採用了自動分區的方案，隨着使用服務器的系統用戶數量不斷增多，根據分區經常面臨磁盤空間耗盡的情況，偶爾有幾次還導致系統無法啓動。爲了解決這些問題，現需要爲服務器新增加一塊SCSI硬盤，並將用戶目錄“/home”中的數據遷移到該硬盤中，要求遷移不能影響原有用戶賬號的使用。
（二）需求描述
在虛擬機中添加一塊80G的SCSI磁盤。
在新硬盤中建立一個20G的分區，用於存放所有普通用戶的宿主文件夾
新建的分區仍然掛載到“/home”目錄下，需要導入系統中原有用戶的數據
服務器在每次開機後能夠自動掛載該分區
（三）推薦步驟
1. 關機後添加新硬盤，重新開機進入RHEL6系統 2. 分區並格式化 1. 使用fdisk命令對新硬盤進行分區，建立一個20GB的主分區（“/dev/sdb1”） 2. 執行“partprobe”更新分區表信息，使用mkfs命令將上一步新建的分區格式化爲ext4文件系統 3. 遷移“/home”分區 1. 轉移原有“/home"目錄中的內容並做好備份 2. 修改“/etc/fstab”文件中的分區掛載設置。 3. 按“/etc/fstab”文件中的設置將新建的分區掛載到“/home”目錄下。 4. 將本步驟1中備份的數據複製到新掛載的“/home”文件系統。
實施過程
實驗案例：遷移/home分區
實驗環境
公司原來安裝的RHEL6服務器採用了自動分區的方案，隨着使用服務器的系統用戶數量不斷增多，根據分區經常面臨磁盤空間耗盡的情況，偶爾有幾次還導致系統無法啓動。爲了解決這些問題，現需要爲服務器新增加一塊SCSI硬盤，並將用戶目錄“/home”中的數據遷移到該硬盤中，要求遷移不能影響原有用戶賬號的使用。
需求描述
在虛擬機中添加一塊80G的SCSI磁盤。
選擇添加硬盤
選擇硬盤類型
選擇硬盤
選擇硬盤容量
指定存儲路徑
添加硬盤完成
在初始界面可以看到新增加的硬盤
查看硬盤信息：
[root@test2 jason]# 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: 0x000d0a36 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/sdb: 85.9 GB, 85899345920 bytes 255 heads, 63 sectors/track, 10443 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: 0xa8f24694 Device Boot Start End Blocks Id System /dev/sdb1 1 2612 20980858+ 83 Linux /dev/sdb2 2613 5224 20980890 83 Linux /dev/sdb3 5225 10443 41921617+ 83 Linux Disk /dev/sdc: 85.9 GB, 85899345920 bytes 255 heads, 63 sectors/track, 10443 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/vg_jason-lv_root: 18.8 GB, 18798870528 bytes 255 heads, 63 sectors/track, 2285 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/vg_jason-lv_swap: 2147 MB, 2147483648 bytes 255 heads, 63 sectors/track, 261 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 [root@test2 jason]#
新建的分區：
在新硬盤中建立一個20G的分區，用於存放所有普通用戶的宿主文件夾
分區前查看sdc信息：
[root@test2 jason]# Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with disk identifier 0x764db371. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): **Disk /dev/sdc: 85.9 GB, 85899345920 bytes** 255 heads, 63 sectors/track, 10443 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: 0x764db371 Device Boot Start End Blocks Id System
截圖：
分區；查看信息；保存：
[root@test2 jason]# fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x8967e34e.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help):
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10443, default 10443): +20G
Command (m for help):
Disk /dev/sdc: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 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: 0x8967e34e
Device Boot Start End Blocks Id System
/dev/sdc1 1 2612 20980858+ 83 Linux
Command (m for help):
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.格式化成ext4：
[root@test2 jason]# mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 1313760 inodes, 5245214 blocks 262260 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 161 block groups 32768 blocks per group, 32768 fragments per group 8160 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 23 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@test2 jason]#
截圖：
探測/dev/sdc1：
[root@test2 jason]# sdc sdc1 [root@test2 jason]# partprobe /dev/sdc
查看
[root@test2 jason]# fdisk -l /dev/sdc1 Disk /dev/sdc1: 21.5 GB, 21484399104 bytes 255 heads, 63 sectors/track, 2611 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 [root@test2 jason]#
截圖：
新建的分區仍然掛載到“/home”目錄下，需要導入系統中原有用戶的數據
備份/home
具體方式tar czvf home.bak.tar.gzip /root/Documents
[root@test2 ~]# tar czvf home.bak.tar.gzip /home/*
截圖：
查看備份後的信息：
[root@test2 ~]# ls anaconda-ks.cfg Downloads install.log man.txt Pictures Videos Desktop etc.tar.gz install.log.syslog Music Public Documents home.bak.tar.gzip man2.txt mvtotrash Templates [root@test2 ~]#
截圖：
服務器在每次開機後能夠自動掛載該分區
修改/etc/fstab
[root@test2 Documents]# vi /etc/fstab # # /etc/fstab # Created by anaconda on Wed May 18 04:04:40 2016 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/vg_jason-lv_root / ext4 defaults 1 1 UUID=12a13375-c595-4876-9fc2-3158f535861d /boot ext4 defaults 1 2 /dev/mapper/vg_jason-lv_swap swap swap defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
截圖：
掛載，mount
[root@test2 Documents]# mount /home
查看mount信息：
[root@test2 Documents]# mount /dev/mapper/vg_jason-lv_root 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) /dev/sda1 on /boot type ext4 (rw) none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw) vmware-vmblock on /var/run/vmblock-fuse type fuse.vmware-vmblock (rw,nosuid,nodev,default_permissions,allow_other) gvfs-fuse-daemon on /root/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev) /dev/sr0 on /media/CentOS_6.5_Final type iso9660 (ro,nosuid,nodev,uhelper=udisks,uid=0,gid=0,iocharset=utf8,mode=0400,dmode=0500) [root@test2 Documents]#
截圖：
掛載後home目錄下只有lost+found：
[root@test2 Documents]# cd /home [root@test2 home]# ls lost+found [root@test2 home]#
截圖：
恢復/home：
[root@test2 ~]# tar xzvf home.bak.tar.gzip -C /home
截圖：
恢復結果：
[root@test2 ~]# cd /home [root@test2 home]# ls home lost+found [root@test2 home]#
截圖：
分析：可能是恢復路徑的問題
恢復路徑得寫/：
[root@test2 Documents]# cd /home [root@test2 home]# ls home [root@test2 home]# rm -rf home [root@test2 home]# ls
繼續恢復：
[root@test2 ~]# tar xzvf home.bak.tar.gzip -c /
恢復完成：
[root@test2 ~]# cd /home [root@test2 home]# ls backup jason
截圖：
