实验案例一：迁移/home分区
（一）实验环境
公司原来安装的RHEL6服务器采用了自动分区的方案，随着使用服务器的系统用户数量不断增多，根据分区经常面临磁盘空间耗尽的情况，偶尔有几次还导致系统无法启动。为了解决这些问题，现需要为服务器新增加一块SCSI硬盘，并将用户目录“/home”中的数据迁移到该硬盘中，要求迁移不能影响原有用户账号的使用。
（二）需求描述
在虚拟机中添加一块80G的SCSI磁盘。
在新硬盘中建立一个20G的分区，用于存放所有普通用户的宿主文件夹
新建的分区仍然挂载到“/home”目录下，需要导入系统中原有用户的数据
服务器在每次开机后能够自动挂载该分区
（三）推荐步骤
1. 关机后添加新硬盘，重新开机进入RHEL6系统2. 分区并格式化 1. 使用fdisk命令对新硬盘进行分区，建立一个20GB的主分区（“/dev/sdb1”） 2. 执行“partprobe”更新分区表信息，使用mkfs命令将上一步新建的分区格式化为ext4文件系统3. 迁移“/home”分区 1. 转移原有“/home"目录中的内容并做好备份 2. 修改“/etc/fstab”文件中的分区挂载设置。 3. 按“/etc/fstab”文件中的设置将新建的分区挂载到“/home”目录下。 4. 将本步骤1中备份的数据复制到新挂载的“/home”文件系统。
实施过程
实验案例：迁移/home分区
实验环境
公司原来安装的RHEL6服务器采用了自动分区的方案，随着使用服务器的系统用户数量不断增多，根据分区经常面临磁盘空间耗尽的情况，偶尔有几次还导致系统无法启动。为了解决这些问题，现需要为服务器新增加一块SCSI硬盘，并将用户目录“/home”中的数据迁移到该硬盘中，要求迁移不能影响原有用户账号的使用。
需求描述
在虚拟机中添加一块80G的SCSI磁盘。
选择添加硬盘
选择硬盘类型
选择硬盘
选择硬盘容量
指定存储路径
添加硬盘完成
在初始界面可以看到新增加的硬盘
查看硬盘信息：
[root@test2 jason]# fdisk -lDisk /dev/sda: 21.5 GB, 21474836480 bytes255 heads, 63 sectors/track, 2610 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000d0a36 Device Boot Start End Blocks Id System/dev/sda1 * 1 64 512000 83 LinuxPartition 1 does not end on cylinder boundary./dev/sda2 64 2611 20458496 8e Linux LVMDisk /dev/sdb: 85.9 GB, 85899345920 bytes255 heads, 63 sectors/track, 10443 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk 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 LinuxDisk /dev/sdc: 85.9 GB, 85899345920 bytes255 heads, 63 sectors/track, 10443 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/mapper/vg_jason-lv_root: 18.8 GB, 18798870528 bytes255 heads, 63 sectors/track, 2285 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/mapper/vg_jason-lv_swap: 2147 MB, 2147483648 bytes255 heads, 63 sectors/track, 261 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000[root@test2 jason]#
新建的分区：
在新硬盘中建立一个20G的分区，用于存放所有普通用户的宿主文件夹
分区前查看sdc信息：
[root@test2 jason]# Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding 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 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x764db371 Device Boot Start End Blocks Id System
截图：
分区；查看信息；保存：
[root@test2 jason]# fdisk /dev/sdcDevice contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding 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)pPartition number (1-4): 1First cylinder (1-10443, default 1):Using default value 1Last cylinder, +cylinders or +size{K,M,G} (1-10443, default 10443): +20GCommand (m for help): Disk /dev/sdc: 85.9 GB, 85899345920 bytes255 heads, 63 sectors/track, 10443 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x8967e34e Device Boot Start End Blocks Id System/dev/sdc1 1 2612 20980858+ 83 LinuxCommand (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: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks1313760 inodes, 5245214 blocks262260 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=4294967296161 block groups32768 blocks per group, 32768 fragments per group8160 inodes per groupSuperblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000Writing inode tables: doneCreating journal (32768 blocks): doneWriting superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 23 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.[root@test2 jason]#
截图：
探测/dev/sdc1：
[root@test2 jason]# sdc sdc1[root@test2 jason]# partprobe /dev/sdc
查看
[root@test2 jason]# fdisk -l /dev/sdc1Disk /dev/sdc1: 21.5 GB, 21484399104 bytes255 heads, 63 sectors/track, 2611 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000[root@test2 jason]#
截图：
新建的分区仍然挂载到“/home”目录下，需要导入系统中原有用户的数据
备份/home
具体方式tar czvf home.bak.tar.gzip /root/Documents
[root@test2 ~]# tar czvf home.bak.tar.gzip /home/*
截图：
查看备份后的信息：
[root@test2 ~]# lsanaconda-ks.cfg Downloads install.log man.txt Pictures VideosDesktop etc.tar.gz install.log.syslog Music PublicDocuments home.bak.tar.gzip man2.txt mvtotrash Templates[root@test2 ~]#
截图：
服务器在每次开机后能够自动挂载该分区
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 1UUID=12a13375-c595-4876-9fc2-3158f535861d /boot ext4 defaults 1 2/dev/mapper/vg_jason-lv_swap swap swap defaults 0 0tmpfs /dev/shm tmpfs defaults 0 0devpts /dev/pts devpts gid=5,mode=620 0 0sysfs /sys sysfs defaults 0 0proc /proc proc defaults 0 0~~~~~~~~~~~~~~
截图：
挂载，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]#
截图：
挂载后home目录下只有lost+found：
[root@test2 Documents]# cd /home[root@test2 home]# lslost+found[root@test2 home]#
截图：
恢复/home：
[root@test2 ~]# tar xzvf home.bak.tar.gzip -C /home
截图：
恢复结果：
[root@test2 ~]# cd /home[root@test2 home]# lshome lost+found[root@test2 home]#
截图：
分析：可能是恢复路径的问题
恢复路径得写/：
[root@test2 Documents]# cd /home[root@test2 home]# lshome[root@test2 home]# rm -rf home[root@test2 home]# ls
继续恢复：
[root@test2 ~]# tar xzvf home.bak.tar.gzip -c /
恢复完成：
[root@test2 ~]# cd /home[root@test2 home]# lsbackup jason
截图：
