为了完成此实验，请确保Linux系统有足够的磁盘空间，如果磁盘空间不足则需要添加磁盘。本文档扩展Linux系统根分区的方法是在虚拟环境下做的，在生产环境下同样适用。
环境：
VMware虚拟机Red Hat 6.5
技术：
逻辑卷管理(LVM)
具体步骤：
1.查看磁盘空间
[root@localhost ~]# df -h #查看磁盘空间，根分区的大小是18G，已经用了43%。 Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup-lv_root 18G 7.0G 9.5G 43% / tmpfs 2.0G 76K 2.0G 1% /dev/shm /dev/sda1 485M 40M 421M 9% /boot /dev/sr0 3.6G 3.6G 0 100% /media/cdrom 2.创建磁盘分区
[root@localhost ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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: 0x00083529 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 2611 20458496 8e Linux LVM #/dev/sdb盘还有足够的空间 Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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/VolGroup-lv_root: 18.8 GB, 18798870528 bytes 255 heads, 63 sectors/track, 2285 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/VolGroup-lv_swap: 2147 MB, 2147483648 bytes 255 heads, 63 sectors/track, 261 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 [root@localhost ~]# fdisk /dev/sdb Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with disk identifier 0xac7c929b. 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): p Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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: 0xac7c929b Device Boot Start End Blocks Id System Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1#分区号 First cylinder (1-2610, default 1): #回车用默认的 Using default value 1 Last cylinder, +cylinders or +size{K,M,G} (1-2610, default 2610): #回车用默认的 Using default value 2610 Command (m for help): t #改变类型 Selected partition 1 Hex code (type L to list codes): 8e #LVM的分区代码 Changed system type of partition 1 to 8e (Linux LVM) Command (m for help): p Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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: 0xac7c929b Device Boot Start End Blocks Id System /dev/sdb1 1 2610 20964793+ 8e Linux LVM Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. [root@localhost ~]# partprobe #将磁盘分区表变化信息通知内核，请求操作系统重新加载分区表，有些小报错不要紧。 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. Warning: WARNING: the kernel failed to re-read the partition table on /dev/sdb (Device or resource busy). As a result, it may not reflect all of your changes until after reboot. Warning: Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only. Warning: Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only. Error: Invalid partition table - recursive partition on /dev/sr0. 3.创建物理卷
[root@localhost ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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: 0x00083529 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 2611 20458496 8e Linux LVM Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 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: 0xac7c929b Device Boot Start End Blocks Id System /dev/sdb1 1 2610 20964793+ 8e Linux LVM Disk /dev/mapper/VolGroup-lv_root: 18.8 GB, 18798870528 bytes 255 heads, 63 sectors/track, 2285 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/VolGroup-lv_swap: 2147 MB, 2147483648 bytes 255 heads, 63 sectors/track, 261 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 [root@localhost ~]# pvcreate /dev/sdb1 #由fdisk -l查到LVM卷是/dev/sdb1，所以用/dev/sdb1来创建物理卷。 Physical volume "/dev/sdb1" successfully created 4.扩展卷组
[root@localhost ~]# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name VolGroup PV Size 19.51 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 4994 Free PE 0 Allocated PE 4994 PV UUID qkBdcn-RQaR-ZliO-Ja2S-RhMC-stw8-CO213I "/dev/sdb1" is a new physical volume of "19.99 GiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 19.99 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID H7tDqG-6AZv-yBSA-U0ov-Ni0y-dlPA-kAA83i [root@localhost ~]# vgextend VolGroup /dev/sdb1 Volume group "VolGroup" successfully extended You have new mail in /var/spool/mail/root [root@localhost ~]# vgdisplay --- Volume group --- VG Name VolGroup 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 39.50 GiB PE Size 4.00 MiB Total PE 10112 Alloc PE / Size 4994 / 19.51 GiB Free PE / Size 5118 / 19.99 GiB VG UUID dc0vI9-KzGu-4S59-A1xv-NM4Y-rYBF-3jDNRn 5.扩展逻辑卷
[root@localhost ~]# lvextend -l +100%free /dev/mapper/VolGroup-lv_root #free也可以大写FREE Extending logical volume lv_root to 37.50 GiB Logical volume lv_root successfully resized [root@localhost ~]# blkid /dev/mapper/VolGroup-lv_root #查看分区文件系统类型 /dev/mapper/VolGroup-lv_root: UUID="972fdddd-ddb8-469f-a342-e075eaeabeb2" TYPE="ext4" [root@localhost ~]# e2fsck -f /dev/mapper/VolGroup-lv_root #e2fsck -f检查分区 e2fsck 1.41.12 (17-May-2010) /dev/mapper/VolGroup-lv_root is mounted. e2fsck: Cannot continue, aborting. [root@localhost ~]# resize2fs /dev/mapper/VolGroup-lv_root #如果分区是xfs系统，则用xfs_growfs命令对文件系统进行扩展 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line resizing required old desc_blocks = 2, new_desc_blocks = 3 Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 9830400 (4k) blocks. The filesystem on /dev/mapper/VolGroup-lv_root is now 9830400 blocks long. [root@localhost ~]# df -h #查看磁盘空间，根分区已扩展到37G。 Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup-lv_root 37G 7.0G 29G 20% / tmpfs 2.0G 224K 2.0G 1% /dev/shm /dev/sda1 485M 40M 421M 9% /boot /dev/sr0 3.6G 3.6G 0 100% /media/cdrom
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