虚拟机磁盘逻辑卷扩容
在esx server上安装虚拟机时，由于只分配了默认的8GB磁盘空间。空间不太够，所以在虚拟机上把分配磁盘空间扩大的20GB。在esx server上扩容磁盘空间的方法很简单，在此不提，下面具体说说如何把该扩容的磁盘空间
在虚拟机上应用上去。
以下是未扩容前的状态：
[root@localhost ~]# fdisk -l Disk /dev/sda: 21.4 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 83 Linux /dev/sda2 14 1044 8281507+ 8e Linux LVM [root@localhost ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup-LogVol00 7.0G 4.8G 1.8G 73% / /dev/sda1 99M 12M 82M 13% /boot tmpfs 187M 0 187M 0% /dev/shm /dev/hdc 183M 183M 0 100% /media/VMware Tools
可以看到sda有21.4GB，但是只利用了sda1和sda2；根目录挂载在/dev/mapper/VolGroup-LogVol00，我们要做的是，把sda上剩余的空间扩容到/dev/mapper/VolGroup-LogVol00。
1）首先，通过fdisk /dev/sda命令将sda剩余空间创建一个分区：
[root@localhost ~]# fdisk /dev/sda The number of cylinders for this disk is set to 2610. 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): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 3 First cylinder (1045-2610, default 1045): Using default value 1045 Last cylinder or +size or +sizeM or +sizeK (1045-2610, default 2610): Using default value 2610 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. [root@localhost ~]#
此时可以看到多了一个sda3的分区：
[root@localhost ~]# fdisk -l Disk /dev/sda: 21.4 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 83 Linux /dev/sda2 14 1044 8281507+ 8e Linux LVM /dev/sda3 1045 2610 12578895 83 Linux
此时查看了一下/dev下，不知道为何没有/dev/sda3，于是重启了一下虚拟机RHEL，重启完成后，出现了/dev/sda3.
一开始在这个地方折腾了一会，如果不重启，在利用命令pvcreate /dev/sda3创建pv时，总是提示Device /dev/sda3 not found (or ignored by filtering).
重启完成后，进入lvm模式，创建pv：
lvm> pvcreate /dev/sda3 Physical volume "/dev/sda3" successfully created
扩容vg：vgextend vg_gcc /dev/sda3
lvm> vgextend VolGroup /dev/sda3 /dev/cdrom: open failed: Read-only file system Attempt to close device '/dev/cdrom' which is not open. Volume group "VolGroup" successfully extended
把lv扩容到vg的剩余容量：lvextend /dev/vg_gcc/lv_root /dev/sda3
lvm> lvextend /dev/VolGroup/LogVol00 /dev/sda3 Extending logical volume LogVol01 to 12.72 GB Logical volume LogVol01 successfully resized
最后，通过resize2fs命令令新增的空间在线（on-line）生效：resize2fs /dev/vg_gcc/lv_root
[root@localhost dev]# resize2fs /dev/VolGroup/LogVol00 resize2fs 1.39 (29-May-2006) Filesystem at /dev/VolGroup/LogVol00 is mounted on /; on-line resizing required Performing an on-line resize of /dev/VolGroup/LogVol00 to 5005312 (4k) blocks. The filesystem on /dev/VolGroup/LogVol00 is now 5005312 blocks long.
效果如下：
[root@localhost dev]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup-LogVol00 19G 4.8G 13G 28% / /dev/sda1 99M 12M 82M 13% /boot tmpfs 187M 0 187M 0% /dev/shm /dev/hdc 3.4G 3.4G 0 100% /media/RHEL_5.2 x86_64 DVD
至此，扩容已成功完成。
