环境：
CentOS 6.9
平常在VMware上创建Linux系统虚拟机的时候，往往当时不会给太多的磁盘空间，在后期的使用过程中经常会遇到磁盘空间不足的情况，所以需要对Linux系统扩展磁盘空间。
扩展磁盘步骤：
1.磁盘扩展
注意：只能在虚拟机关机的情况下操作，并且这个虚拟机上没有磁盘快照文件，如有需要删除才可以扩展。
此时虽然在VMware虚拟机管理界面的扩容操作已经完成，但是这还只是扩容的第一步，后面还需要到操作系统内部进行操作。
2.查看分区信息
[root@test-centos6 ~]# fdisk -l Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 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: 0x000a16bc 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/mapper/vg_testcentos6-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/vg_testcentos6-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@test-centos6 ~]# lsblk //列出块设备信息 NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 447M 0 rom sda 8:0 0 60G 0 disk ├─sda1 8:1 0 500M 0 part /boot └─sda2 8:2 0 19.5G 0 part ├─vg_testcentos6-lv_root (dm-0) 253:0 0 17.5G 0 lvm / └─vg_testcentos6-lv_swap (dm-1) 253:1 0 2G 0 lvm [SWAP]
可以看到目前磁盘/dev/sda已经有两个分区，分别为sda1、sda2。
3.新建分区sda3
[root@test-centos6 ~]# fdisk /dev/sda 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): m //列出可以执行的命令 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 //选择分区，删除现有分区 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 //建立新的磁盘分区 Command action e extended //逻辑分区 p primary partition (1-4) //主分区 p //建立主分区 Partition number (1-4): 3 //输入分区号 First cylinder (2611-7832, default 2611): //分区起始位置（可直接回车也可以根据情况输入） Using default value 2611 Last cylinder, +cylinders or +size{K,M,G} (2611-7832, default 7832): //回车 Using default value 7832 Command (m for help): p //列出磁盘目前的分区情况 Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 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: 0x000a16bc 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/sda3 2611 7832 41939020 83 Linux Command (m for help): w //对分区操作进行保存 The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: 设备或资源忙. 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. //正在同步磁盘 [root@test-centos6 ~]# fdisk -l //查看分区创建情况 Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 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: 0x000a16bc 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/sda3 2611 7832 41939020 83 Linux Disk /dev/mapper/vg_testcentos6-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/vg_testcentos6-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
4.重启系统并格式化分区sda3文件系统
[root@test-centos6 ~]# reboot [root@test-centos6 ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 447M 0 rom sda 8:0 0 60G 0 disk ├─sda1 8:1 0 500M 0 part /boot ├─sda2 8:2 0 19.5G 0 part │ ├─vg_testcentos6-lv_root (dm-0) 253:0 0 17.5G 0 lvm / │ └─vg_testcentos6-lv_swap (dm-1) 253:1 0 2G 0 lvm [SWAP] └─sda3 8:3 0 40G 0 part [root@test-centos6 ~]# mkfs.ext4 /dev/sda3 //将/dev/sda3分区文件系统格式化为ext4 mke2fs 1.41.12 (17-May-2010) 文件系统标签= 操作系统:Linux 块大小=4096 (log=2) 分块大小=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 2621440 inodes, 10484755 blocks 524237 blocks (5.00%) reserved for the super user 第一个数据块=0 Maximum filesystem blocks=4294967296 320 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624 正在写入inode表: 完成 Creating journal (32768 blocks): 完成 Writing superblocks and filesystem accounting information: 完成 This filesystem will be automatically checked every 35 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.
5.创建物理卷（pv）
此步骤可省略:当将分区直接添加到卷组（vg）时，LVM会自动将分区转换为物理卷（pv）。
[root@test-centos6 ~]# lvm lvm> pvcreate /dev/sda3 //创建物理卷pv Physical volume "/dev/sda3" successfully created lvm> pvdisplay //显示物理卷pv信息 --- Physical volume --- PV Name /dev/sda2 VG Name vg_testcentos6 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 jMIPOc-sduo-sl4T-6iQ5-ledQ-1w9O-cweeEC "/dev/sda3" is a new physical volume of "40.00 GiB" --- NEW Physical volume --- PV Name /dev/sda3 VG Name PV Size 40.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID PVrdc7-fUEX-PAxZ-ME92-IuNU-khDC-c5tYlp lvm> pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name vg_testcentos6 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 jMIPOc-sduo-sl4T-6iQ5-ledQ-1w9O-cweeEC "/dev/sda3" is a new physical volume of "40.00 GiB" --- NEW Physical volume --- PV Name /dev/sda3 VG Name PV Size 40.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID PVrdc7-fUEX-PAxZ-ME92-IuNU-khDC-c5tYlp
6.查看并创建卷组（vg）
lvm> vgdisplay //查看需要扩展的卷组vg名称 --- Volume group --- VG Name vg_testcentos6 //卷组vg名称 System ID Format lvm2 Metadata Areas 3 Metadata Sequence No 6 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 3 Act PV 3 VG Size 59.49 GiB PE Size 4.00 MiB Total PE 17790 Alloc PE / Size 15232 / 19.50 GiB Free PE / Size 2558 / 9.99 GiB VG UUID yVVWYi-mV3I-f1WI-2QeH-HkVT-oBXP-2KkQ8v lvm> vgextend vg_testcentos6 /dev/sda3 //扩展卷组（这里的“vg_testcentos6”名称为上面的卷组名称） Volume group "vg_testcentos6" successfully extended
7.扩展逻辑卷（lv）
[root@test-centos6 ~]# df -h //查看扩展路径，这里也可以用fdisk -l查看 Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_testcentos6-lv_root -----》 //**扩展路径** 18G 18G 0 100% / tmpfs 1.9G 0 1.9G 0% /dev/shm /dev/sda1 485M 58M 403M 13% /boot [root@test-centos6 ~]# lvm //进入LVM管理器 lvm> lvextend -L +39.99G /dev/mapper/vg_testcentos6-lv_root //扩展逻辑卷lv大小（通过fdisk -l/df -h查看要扩展过去的磁盘） Rounding size to boundary between physical extents: 39.99 GiB. Size of logical volume vg_testcentos6/lv_root changed from 17.51 GiB (4482 extents) to 57.50 GiB (14720 extents) Logical volume lv_root successfully resized. lvm> lvscan ACTIVE '/dev/vg_testcentos6/lv_root' [57.50 GiB] inherit ACTIVE '/dev/vg_testcentos6/lv_swap' [2.00 GiB] inherit lvm> pvscan PV /dev/sda2 VG vg_testcentos6 lvm2 [19.51 GiB / 0 free] PV /dev/sda3 VG vg_testcentos6 lvm2 [39.99 GiB / 0 free] Total: 2 [59.50 GiB] / in use: 2 [59.50 GiB] / in no VG: 0 [0 ] lvm> exit Exiting.
8.查看分区情况
[root@test-centos6 ~]# fdisk -l Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 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: 0x000a16bc 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/sda3 2611 7832 41939020 83 Linux Disk /dev/mapper/vg_testcentos6-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/vg_testcentos6-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
注意：上面虽然显示物理卷/dev/sdb3有40G空闲，但是这里不能全部使用，可能只有39.99G可以使用。
7.激活即重新读取磁盘信息
查看/dev/mapper/vg_testcentos6-lv_root的Type为ext4，所以使用resize2fs；如果文件类型是 xfs ，则使用xfs_growfs命令格式化。
[root@test-centos6 ~]# blkid //查看文件系统 /dev/sda1: UUID="32a489a3-65c2-43a4-9aff-12c03eabc4dd" TYPE="ext4" /dev/sda2: UUID="jMIPOc-sduo-sl4T-6iQ5-ledQ-1w9O-cweeEC" TYPE="LVM2_member" /dev/sda3: UUID="PVrdc7-fUEX-PAxZ-ME92-IuNU-khDC-c5tYlp" TYPE="LVM2_member" /dev/mapper/vg_testcentos6-lv_root: UUID="e8adf717-e78c-4845-a750-2a22a60689ed" TYPE="ext4" //可以看到文件系统格式化为ext4 /dev/mapper/vg_testcentos6-lv_swap: UUID="ac33f130-95cc-4046-8bdd-db2d7c450f6d" TYPE="swap" [root@test-centos6 ~]# resize2fs /dev/mapper/vg_testcentos6-lv_root //ext4文件系统使用resize2fs resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/vg_testcentos6-lv_root is mounted on /; on-line resizing required old desc_blocks = 2, new_desc_blocks = 4 Performing an on-line resize of /dev/mapper/vg_testcentos6-lv_root to 15073280 (4k) blocks. The filesystem on /dev/mapper/vg_testcentos6-lv_root is now 15073280 blocks long. [root@test-centos6 ~]# df -h //查看激活状态 Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_testcentos6-lv_root 57G 4.4G 50G 9% / tmpfs 1.9G 244K 1.9G 1% /dev/shm /dev/sda1 485M 58M 403M 13% /boot
可以看到现在我们的磁盘已经从最开始的19G扩展到了57G。
