接收到数据转储项目组需求，需要将虚拟机的硬盘扩容，满足后续运维需求； 操作系统:CENTOS 6

命令清单

  • lsblk:查看分区信息
  • df -h查看文件系统及空间使用信息
  • fdisk [-l][/dev/sda]查看，修改系统分区信息，创建分区
  • pvdisplsy查看LVM中PV信息
  • vgdisplay查看LVM中VG信息
  • lvdisplay查看LVM中LV信息
  • pvcreate [/dev/sda3]基于现有分区，创建PV
  • vgextend [vg_bigdata] [/dev/sda3]扩充VG
  • lvextend -L +149G /dev/vg_bigdata/lv_home扩充LV
  • resize2fs /dev/vg_bigdata/lv_home 增大或者收缩未加载的“ext2/ext3”文件系统的大小。如果文件系统是处于mount状态下，那么它只能做到扩容

操作步骤

  1. 在虚拟机控制台，扩展现有硬盘大小，步骤如下图所示
    虚拟机扩展硬盘大小 - 图1
  2. ssh登录进目标系统ssh root@172.16.0.250

  3. 查看系统分析信息及文件系统信息，主要关注LV名称与挂载点

    1. [root@bigdata ~]# lsblk
    2. NAME                          MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
    3. sda                             8:0    0   650G  0 disk 
    4. ©À©¤sda1                          8:1    0   500M  0 part /boot
    5. ©¸©¤sda2                          8:2    0 499.5G  0 part 
    6. ©À©¤vg_bigdata-lv_root (dm-0) 253:0    0    50G  0 lvm  /
    7. ©À©¤vg_bigdata-lv_swap (dm-1) 253:1    0   7.9G  0 lvm  [SWAP]
    8. ©¸©¤vg_bigdata-lv_home (dm-2) 253:2    0 441.7G  0 lvm  /home
    9. sr0                            11:0    1  1024M  0 rom  
    10. [root@bigdata ~]# df -h
    11. Filesystem            Size  Used Avail Use% Mounted on
    12. /dev/mapper/vg_bigdata-lv_root
    13.                     50G  2.5G   45G   6% /
    14. tmpfs                 7.8G     0  7.8G   0% /dev/shm
    15. /dev/sda1             477M   40M  412M   9% /boot
    16. /dev/mapper/vg_bigdata-lv_home
    17.                    435G  6.1G  407G   2% /home

    lsblk可以看到硬盘已经扩充了，需要将扩充的150G的空间加到vg_bigdata-lv_home中

  4. 首先查看当前分区信息，添加磁盘分区

    1. [root@bigdata ~]# fdisk -l
    2. Disk /dev/sda: 697.9 GB, 697932185600 bytes
    3. 255 heads, 63 sectors/track, 84852 cylinders
    4. Units = cylinders of 16065 * 512 = 8225280 bytes
    5. Sector size (logical/physical): 512 bytes / 512 bytes
    6. I/O size (minimum/optimal): 512 bytes / 512 bytes
    7. Disk identifier: 0x00014553
    8. Device Boot      Start         End      Blocks   Id  System
    9. /dev/sda1   *           1          64      512000   83  Linux
    10. Partition 1 does not end on cylinder boundary.
    11. /dev/sda2              64       65271   523774976   8e  Linux LVM
    12. Disk /dev/mapper/vg_bigdata-lv_root: 53.7 GB, 53687091200 bytes
    13. 255 heads, 63 sectors/track, 6527 cylinders
    14. Units = cylinders of 16065 * 512 = 8225280 bytes
    15. Sector size (logical/physical): 512 bytes / 512 bytes
    16. I/O size (minimum/optimal): 512 bytes / 512 bytes
    17. Disk identifier: 0x00000000
    18. Disk /dev/mapper/vg_bigdata-lv_swap: 8438 MB, 8438939648 bytes
    19. 255 heads, 63 sectors/track, 1025 cylinders
    20. Units = cylinders of 16065 * 512 = 8225280 bytes
    21. Sector size (logical/physical): 512 bytes / 512 bytes
    22. I/O size (minimum/optimal): 512 bytes / 512 bytes
    23. Disk identifier: 0x00000000
    24. Disk /dev/mapper/vg_bigdata-lv_home: 474.2 GB, 474216398848 bytes
    25. 255 heads, 63 sectors/track, 57653 cylinders
    26. Units = cylinders of 16065 * 512 = 8225280 bytes
    27. Sector size (logical/physical): 512 bytes / 512 bytes
    28. I/O size (minimum/optimal): 512 bytes / 512 bytes
    29. Disk identifier: 0x00000000
    30. [root@bigdata ~]# fdisk /dev/sda
    31. WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
    32.       switch off the mode (command 'c') and change display units to
    33.       sectors (command 'u').
    34. Command (m for help): m
    35. Command action
    36. a   toggle a bootable flag
    37. b   edit bsd disklabel
    38. c   toggle the dos compatibility flag
    39. d   delete a partition
    40. l   list known partition types
    41. m   print this menu
    42. n   add a new partition
    43. o   create a new empty DOS partition table
    44. p   print the partition table
    45. q   quit without saving changes
    46. s   create a new empty Sun disklabel
    47. t   change a partition's system id
    48. u   change display/entry units
    49. v   verify the partition table
    50. w   write table to disk and exit
    51. x   extra functionality (experts only)
    52. Command (m for help): n
    53. Command action
    54. e   extended
    55. p   primary partition (1-4)
    56. p
    57. Partition number (1-4): 2
    58. Partition 2 is already defined.  Delete it before re-adding it.
    59. Command (m for help): n
    60. Command action
    61. e   extended
    62. p   primary partition (1-4)
    63. p
    64. Partition number (1-4): 3
    65. First cylinder (65271-84852, default 65271): 
    66. Using default value 65271
    67. Last cylinder, +cylinders or +size{K,M,G} (65271-84852, default 84852): 
    68. Using default value 84852
    69. Command (m for help): m
    70. Command action
    71. a   toggle a bootable flag
    72. b   edit bsd disklabel
    73. c   toggle the dos compatibility flag
    74. d   delete a partition
    75. l   list known partition types
    76. m   print this menu
    77. n   add a new partition
    78. o   create a new empty DOS partition table
    79. p   print the partition table
    80. q   quit without saving changes
    81. s   create a new empty Sun disklabel
    82. t   change a partition's system id
    83. u   change display/entry units
    84. v   verify the partition table
    85. w   write table to disk and exit
    86. x   extra functionality (experts only)
    87. Command (m for help): w
    88. The partition table has been altered!
    89. Calling ioctl() to re-read partition table.
    90. WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.
    91. The kernel still uses the old table. The new table will be used at
    92. the next reboot or after you run partprobe(8) or kpartx(8)
    93. Syncing disks.
    • 此次分区创建为创建了第三个主分区，注意创建过程中各个选项的选择，另外在这个场景下，创建主分区或者扩展分区都是可以的；
    • 创建分区的过程中会涉及到分区大小的选择，这个场景下为全部分配，
      First cylinder (65271-84852, default 65271):
      Using default value 65271
      Last cylinder, +cylinders or +size{K,M,G} (65271-84852, default 84852):
      注意分区大小的指定
    • 分区创建完成后按w保存，重启系统

  5. 创建PV

    1. [root@bigdata ~]# pvcreate /dev/sda3
    2. Physical volume "/dev/sda3" successfully created

  6. 扩展VG

    1. [root@bigdata ~]# vgextend vg_bigdata /dev/sda3
    2. Volume group "vg_bigdata" successfully extended

  7. 扩展LV

    1. [root@bigdata ~]# lvextend -L +149G /dev/vg_bigdata/lv_home
    2. Size of logical volume vg_bigdata/lv_home changed from 441.65 GiB (113062 extents) to 590.65 GiB (151206 extents).
    3. Logical volume lv_home successfully resized.

  8. 扩容文件系统

    1. [root@bigdata ~]# resize2fs /dev/vg_bigdata/lv_home
    2. resize2fs 1.41.12 (17-May-2010)
    3. Filesystem at /dev/vg_bigdata/lv_home is mounted on /home; on-line resizing required
    4. old desc_blocks = 28, new_desc_blocks = 37
    5. Performing an on-line resize of /dev/vg_bigdata/lv_home to 154834944 (4k) blocks.
    6. The filesystem on /dev/vg_bigdata/lv_home is now 154834944 blocks long.

  9. df -h查看扩容后的文件系统信息

    1. [root@bigdata ~]# df -h
    2. Filesystem            Size  Used Avail Use% Mounted on
    3. /dev/mapper/vg_bigdata-lv_root
    4.                     50G  2.5G   45G   6% /
    5. tmpfs                 7.8G     0  7.8G   0% /dev/shm
    6. /dev/sda1             477M   40M  412M   9% /boot
    7. /dev/mapper/vg_bigdata-lv_home
    8.                    582G  6.1G  546G   2% /home

    知识点说明

  10. LINUX中的LVM管理与AIX中的LVM管理是相通的，均存在PV/VG/LV/文件系统的概念，只是在具体操作上命令不同；

  11. 在AIX中，PV一般对应一块物理硬盘，在LINUX上，本场景对应的是磁盘的一个分区，理论上物理硬盘也是可以的，比如将第一步扩展当前硬盘大小变更为添加一个新的硬盘；
  12. AIX与LINUX，扩容的步骤都是一致的，如果当前VG有空间，则直接扩展文件系统，如果没有空间，则添加硬盘(扩展硬盘)，创建PV(linux下先分区)，加入VG，扩展LV，扩展文件系统；

  13. AIX下扩展大小要注意mirror的使用，一定要遵守先扩LV再扩文件系统的步骤，如果不按照此步骤操作，可能导致镜像盘的大小分配不平均；

    参考资料

  14. CentOS添加磁盘分区

  15. Centos下磁盘管理—-分区
  16. lvextend 扩展逻辑卷大小
  17. Centos/Linux下调整分区大小（以home和根分区为例）