======================================================== 背景：開發伺服器是虛擬機器，原來只規劃了2G，後來發現硬碟不夠用了，需要進行擴容。 參考文章：《實戰Linux下VMware虛擬機器根目錄空間擴充》 http://blog.sina.com.cn/s/blog_709919050100wap1.html 注：請首先閱讀參考文章，本文是在其基礎之上，在不同環境中進行的案例。 同時，原文有幾處地方沒有交代的那麼清楚，初學者可能會走彎路，在這裡進行了相應補充。 ======================================================== 看到文章說必須基於LVM，那是不是呢？命令檢驗一下。據說centos預設安裝也是LVM的。 [

[email protected] ~]$lvdisplay  --- Logical volume ---
  LV Path                /dev/vg_vm/lv_root
  LV Name                lv_root
  VG Name                vg_vm
  LV UUID                bWyLlY-hYra-7hPc-2eU9-tXMH-FJFa-7ZLDoF
  LV Write Access        read/write
  LV Creation host, time vm.sss, 2015-01-05 03:29:55 +0800
  LV Status              available
  # open                 1
  LV Size                6.71 GiB
  Current LE             1718
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
  
  --- Logical volume ---
  LV Path                /dev/vg_vm/lv_swap
  LV Name                lv_swap
  VG Name                vg_vm
  LV UUID                oLj3cQ-USD7-JIGZ-HMJz-NlmA-aQf6-lECYyC
  LV Write Access        read/write
  LV Creation host, time vm.sss, 2015-01-05 03:29:56 +0800
  LV Status              available
  # open                 1
  LV Size                816.00 MiB
  Current LE             204
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1 [

[email protected] ~]$sudo fdisk -l Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 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: 0x00036057

   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        1045     7875584   8e  Linux LVM

Disk /dev/mapper/vg_vm-lv_root: 7205 MB, 7205814272 bytes
255 heads, 63 sectors/track, 876 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_vm-lv_swap: 855 MB, 855638016 bytes
255 heads, 63 sectors/track, 104 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 然後，在windows虛擬機器管理軟體上，給虛擬機器擴容——前提是關閉虛擬機器OS。 來個30G，當然，進去之後，可以看到總容量增加了。到32G了，還是沒有發現新的分割槽，虛擬機器軟體也已經提醒了。 [[email protected] ~]$ sudo fdisk /dev/sda 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. 最後一步出現這樣的提示。 但是我們發現，fdisk -l，這個分割槽已經出來了。
   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        1045     7875584   8e  Linux LVM
/dev/sda3            1045        3916    23066662   83  Linux 當然，這時候用ls /dev是看不到sd3的。因為還沒格式化。 sudo mkfs -t ext3 /dev/sda3 現在也是報錯的。 Could not stat /dev/sdb3之類的。
既然上次已經提示了要reboot，那就roboot一下吧。 [[email protected] ~]$partprobe 還是出現同樣的警告。難道還是不行？ Warning: WARNING: the kernel failed to re-read the partition table on /dev/sda (Device or resource busy).  As a result, it may not reflect all of your changes until after reboot. 管他呢，執行一下格式化吧。 [[email protected] ~]$sudo mkfs -t ext3 /dev/sda3 居然OK了！這不嚇唬人嗎？ [[email protected] ~]$ ll /dev/sda3
brw-rw----. 1 root disk 8, 3 Jan  6 10:33 /dev/sda3 嘿嘿，已經有了哦 然而，看看磁碟空間呢？怎麼還是這幾個分割槽呢 [[email protected] ~]$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/vg_vm-lv_root  6.7G  6.5G   83M  99% /
tmpfs                      495M   80K  495M   1% /dev/shm
/dev/sda1                  485M  326M  134M  71% /boot sudo fdisk -l也可以發現，還是隻有一個LVM的分割槽。    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        1045     7875584   8e  Linux LVM
/dev/sda3            1045        3916    23066662   83  Linux [[email protected] ~]$ sudo lvs
  LV      VG    Attr       LSize   Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root vg_vm -wi-ao----   6.71g                                            
  lv_swap vg_vm -wi-ao---- 816.00m   [[email protected] ~]$ sudo pvcreate /dev/sda3
  dev_is_mpath: failed to get device for 8:3
  Physical volume "/dev/sda3" successfully created 這裡有一個failed，以為出問題了呢，結果下面又success，玩我呢？不管他了。因為一查，都是這樣的提示，沒有問題。 /dev/mapper/vg_vm-lv_root  6.7G  6.5G   83M  99% /
tmpfs                      495M   80K  495M   1% /dev/shm
/dev/sda1                  485M  326M  134M  71% /boot /dev/mapper/vg_vm-lv_root這個應該就是LVM的組名，這裡顯示的不是sda2. 來擴充這個組吧。 [[email protected] ~]$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/vg_vm-lv_root  6.7G  6.5G   83M  99% /
tmpfs                      495M   80K  495M   1% /dev/shm
/dev/sda1                  485M  326M  134M  71% /boot
[[email protected] ~]$ sudo vgextend /dev/mapper/vg_vm-lv_root /dev/sda3
  Volume group name vg_vm/lv_root has invalid characters
[[email protected] ~]$ sudo vgextend /dev/mapper/vg_vm /dev/sda3       
  Volume group "vg_vm" successfully extended 原來這個組名，是-之前的字串——這要是沒有文章看著對比分析，誰知道啊？ [[email protected] ~]$ sudo vgdisplay
  --- Volume group ---
  VG Name               vg_vm
  System ID            
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               29.50 GiB
  PE Size               4.00 MiB
  Total PE              7553
  Alloc PE / Size       1922 / 7.51 GiB
  Free  PE / Size       5631 / 22.00 GiB
  VG UUID               8GwL0o-DTdc-Lmkc-gCCC-RBvv-yOQp-wMgpeq [[email protected] ~]$ sudo lvextend -L +22G /dev/vg_vm/lv_root /dev/sda3
  Extending logical volume lv_root to 28.71 GiB
  Insufficient free space: 5632 extents needed, but only 5631 available 估計是這其中用了一部分。22G沒那麼準了。那麼就21.0G吧 [[email protected] ~]$ sudo lvextend -L +21.9G /dev/vg_vm/lv_root /dev/sda3   Rounding size to boundary between physical extents: 21.90 GiB
  Extending logical volume lv_root to 28.61 GiB
  Logical volume lv_root successfully resized 文中所說的vim /etc/fstab這一個步驟，沒太看明白。 裡面的內容是否有改變？因為看到少了一個mapper 我沒有管他，並沒有對這個檔案進行修改，然後繼續往下。 [[email protected] ~]$ sudo e2fsck -f /dev/vg_vm/lv_root
e2fsck 1.41.12 (17-May-2010)
/dev/vg_vm/lv_root is mounted.
e2fsck: Cannot continue, aborting. 不知為何報錯。但是這只是一個檢查命令，繼續往前吧。 [[email protected] ~]$ sudo resize2fs  /dev/vg_vm/lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_vm/lv_root is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/vg_vm/lv_root to 7500800 (4k) blocks.
The filesystem on /dev/vg_vm/lv_root is now 7500800 blocks long.

[[email protected] ~]$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/vg_vm-lv_root   29G  6.5G   22G  24% /
tmpfs                      495M   80K  495M   1% /dev/shm
/dev/sda1                  485M  326M  134M  71% /boot 可以看到，這個邏輯卷已經成功的擴容，根目錄又可以裝更多東西了。yeah！ ==========================================================================