怎样调整XenServer下面Linux虚拟机的磁盘大小

1. 登录到XenServer。
2. 修改虚拟机磁盘大小
   修改storage 磁盘大小
3. 启动虚拟机
4. 修改分区大小
   fdisk /dev/xvda
   
   The number of cylinders for this disk is set to 5221.
   There is nothing wrong with that, but this is larger than 1024,
   and could in certain setups cause problems with:
   1) software that runs at boot time (e.g., old versions of LILO)
   2) booting and partitioning software from other OSs
      (e.g., DOS FDISK, OS/2 FDISK)
   
   Command (m for help): p
   
   Disk /dev/xvda: 42.9 GB, 42949672960 bytes
   255 heads, 63 sectors/track, 5221 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   
       Device Boot      Start         End      Blocks   Id  System
   /dev/xvda1   *           1          13      104391   83  Linux
   /dev/xvda2              14        2610   20860402+  8e  Linux LVM
   
   Command (m for help): Command (m for help): p
   DOS Compatibility flag is not set
   
   Command (m for help): d
   Partition number (1-4): 2
   
   Command (m for help): n
   Command action
      e   extended
      p   primary partition (1-4)
   p
   Partition number (1-4): 2
   First cylinder (14-5221, default 14):
   Using default value 14
   Last cylinder or +size or +sizeM or +sizeK (14-5221, default 5221):
   Using default value 5221
   
   Command (m for help): t
   Partition number (1-4): 2
   Hex code (type L to list codes): 8e
   Changed system type of partition 2 to 8e (Linux LVM)
   
   Command (m for help): p
   
   Disk /dev/xvda: 42.9 GB, 42949672960 bytes
   255 heads, 63 sectors/track, 5221 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   
       Device Boot      Start         End      Blocks   Id  System
   /dev/xvda1   *           1          13      104391   83  Linux
   /dev/xvda2              14        5221   41833260   8e  Linux LVM
   
   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.
   Syncing disks.
   
   
5. 重启虚拟机：reboot
6. 调整PV大小
   pvs
     PV         VG         Fmt  Attr PSize  PFree
     /dev/xvda2 VolGroup00 lvm2 a-  19.88G    0
   
   
   pvresize -v /dev/xvda2
       Using physical volume(s) on command line
       Archiving volume group "VolGroup00" metadata (seqno 3).
       Resizing physical volume /dev/xvda2 from 636 to 1276 extents.
       Resizing volume "/dev/xvda2" to 83666136 sectors.
       Updating physical volume "/dev/xvda2"
       Creating volume group backup "/etc/lvm/backup/VolGroup00" (seqno 4).
     Physical volume "/dev/xvda2" changed
     1 physical volume(s) resized / 0 physical volume(s) not resized
   
   pvs
     PV         VG         Fmt  Attr PSize  PFree
     /dev/xvda2 VolGroup00 lvm2 a-  39.88G 20.00G
7. 调整LV大小
   lvs
     LV       VG         Attr   LSize  Origin Snap%  Move Log Copy%  Convert
     LogVol00 VolGroup00 -wi-ao 17.84G
     LogVol01 VolGroup00 -wi-ao  2.03G
   
   lvextend -l +100%FREE /dev/VolGroup00/LogVol00
8. 或者 lvextend -l +100%FREE /dev/cl/root
9.   Extending logical volume LogVol00 to 37.84 GB
     Logical volume LogVol00 successfully resized
   
   lvs
     LV       VG         Attr   LSize  Origin Snap%  Move Log Copy%  Convert
     LogVol00 VolGroup00 -wi-ao 37.84G
     LogVol01 VolGroup00 -wi-ao  2.03G
10. 调整分区大小
    df -h
    Filesystem            Size  Used Avail Use% Mounted on
    /dev/mapper/VolGroup00-LogVol00
                         5.7G  4.5G  950M  83% /
    /dev/xvda1             99M   22M   73M  24% /boot
    tmpfs                 2.0G     0  2.0G   0% /dev/shm
    
    resize2fs /dev/mapper/VolGroup00-LogVol00
11. 或者  xfs_growfs /dev/mapper/cl-root
    resize2fs 1.39 (29-May-2006)
    Filesystem at /dev/mapper/VolGroup00-LogVol00 is mounted on /; on-line resizing required
    Performing an on-line resize of /dev/mapper/VolGroup00-LogVol00 to 9920512 (4k) blocks.
    The filesystem on /dev/mapper/VolGroup00-LogVol00 is now 9920512 blocks long.
    
    df -h
    Filesystem            Size  Used Avail Use% Mounted on
    /dev/mapper/VolGroup00-LogVol00
                           37G  4.5G   31G  13% /
    /dev/xvda1             99M   22M   73M  24% /boot
    tmpfs                 2.0G     0  2.0G   0% /dev/shm
    任务完成

12. 遇到的问题
    linux系统为centos7 时， 用 resize2fs 命令出现报错 resize2fs: Bad magic number in super-block while trying to open
    xfs_growfs /dev/root_vg/root 用 xfs_growfs 代替命令 resize2fs