Linux LVM学习总结——放大LV容量

本篇介绍LVM管理中的命令lvresize，我们先创建一个卷组VG VolGroup02，它建立在磁盘/dev/sdc （大小为8G）上。创建逻辑卷LV时，我们故意只使用了一小部分。具体情况如下所示

[root@localhost ~]# vgdisplay

  --- Volume group ---

  VG Name               VolGroup02

  System ID             

  Format                lvm2

  Metadata Areas        1

  Metadata Sequence No  1

  VG Access             read/write

  VG Status             resizable

  MAX LV                0

  Cur LV                0

  Open LV               0

  Max PV                0

  Cur PV                1

  Act PV                1

  VG Size               7.97 GiB

  PE Size               32.00 MiB

  Total PE              255

  Alloc PE / Size       0 / 0   

  Free  PE / Size       255 / 7.97 GiB

  VG UUID               SETgjx-dobd-Uayt-AWgN-HKID-hsYe-tEotIS

[root@localhost ~]# lvcreate -L7.97 -n LogVol00 VolGroup02

  Rounding up size to full physical extent 32.00 MiB

  Logical volume "LogVol00" created

[root@localhost ~]# mkfs -t ext4 /dev/VolGroup02/LogVol00

mke2fs 1.41.12 (17-May-2010)

Filesystem label=

OS type: Linux

Block size=1024 (log=0)

Fragment size=1024 (log=0)

Stride=0 blocks, Stripe width=0 blocks

8192 inodes, 32768 blocks

1638 blocks (5.00%) reserved for the super user

First data block=1

Maximum filesystem blocks=33554432

4 block groups

8192 blocks per group, 8192 fragments per group

2048 inodes per group

Superblock backups stored on blocks: 

        8193, 24577

Writing inode tables: done                            

Creating journal (4096 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 23 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

[root@localhost ~]# cd /

[root@localhost /]# mkdir /u01

[root@localhost /]# mount /dev/VolGroup02/LogVol00 /u01

[root@localhost /]# vi /etc/fstab

#

# /etc/fstab

# Created by anaconda on Mon Aug 17 15:08:21 2015

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

UUID=3440ad55-6486-45ed-876f-e942b08013bf /                       ext4    defaults        1 1

UUID=d3abb655-db70-4c42-967d-57c421abfda0 /boot                   ext4    defaults        1 2

UUID=660624ff-335d-42ca-b779-f130a80d9da8 /home                   ext4    defaults        1 2

UUID=6f534bf0-e486-4937-84ae-ed1221cf34f1 swap                    swap    defaults        0 0

/dev/VolGroup02/LogVol00                  /u01                    ext4    defaults        1 1

tmpfs                   /dev/shm                tmpfs   defaults        0 0

devpts                  /dev/pts                devpts  gid=5,mode=620  0 0

sysfs                   /sys                    sysfs   defaults        0 0

proc                    /proc                   proc    defaults        0 0

此时，我们要放大文件系统/u01的大小，那么就需要使用到lvresize 放大LV容量

[root@localhost ~]# lvscan

  ACTIVE            '/dev/VolGroup02/LogVol00' [32.00 MiB] inherit

[root@localhost ~]# lvdisplay /dev/VolGroup02/LogVol00

  --- Logical volume ---

  LV Path                /dev/VolGroup02/LogVol00

  LV Name                LogVol00

  VG Name                VolGroup02

  LV UUID                OCHwx1-EL9P-6C5J-RNuz-2Xu5-4215-H3xt5s

  LV Write Access        read/write

  LV Creation host, time localhost.localdomain, 2015-09-01 10:50:10 +0800

  LV Status              available

  # open                 1

  LV Size                32.00 MiB

  Current LE             1

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

[root@localhost ~]# lvresize -L +7.89G /dev/VolGroup02/LogVol00

  Rounding size to boundary between physical extents: 7.91 GiB

  Size of logical volume VolGroup02/LogVol00 changed from 32.00 MiB (1 extents) to 7.94 GiB (254 extents).

  Logical volume LogVol00 successfully resized

[root@localhost ~]# resize2fs -p /dev/VolGroup02/LogVol00

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/VolGroup02/LogVol00 is mounted on /u01; on-line resizing required

old desc_blocks = 1, new_desc_blocks = 32

Performing an on-line resize of /dev/VolGroup02/LogVol00 to 8323072 (1k) blocks.

The filesystem on /dev/VolGroup02/LogVol00 is now 8323072 blocks long.

[root@localhost ~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/sda2              27G  6.0G   20G  24% /

tmpfs                 5.9G     0  5.9G   0% /dev/shm

/dev/sda1             477M   32M  420M   8% /boot

/dev/sdb1              99G   60M   94G   1% /home

/dev/mapper/VolGroup02-LogVol00

                      7.7G  2.7M  7.3G   1% /u01

如果我们此时在虚拟机上将磁盘从8G扩展为10G，那么要如何利用扩展的磁盘空间呢？

[root@localhost u01]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes

64 heads, 32 sectors/track, 40960 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000462cf

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           2         501      512000   83  Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2             502       28672    28847104   83  Linux

Partition 2 does not end on cylinder boundary.

/dev/sda3           28673       40960    12582912   82  Linux swap / Solaris

Partition 3 does not end on cylinder boundary.

Disk /dev/sdc: 8589 MB, 8589934592 bytes

64 heads, 32 sectors/track, 8192 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x98c391fe

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1        8192     8388592   83  Linux

Disk /dev/sdb: 107.4 GB, 107374182400 bytes

255 heads, 63 sectors/track, 13054 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: 0x0002488e

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1       13055   104856576   83  Linux

Disk /dev/mapper/VolGroup02-LogVol00: 33 MB, 33554432 bytes

255 heads, 63 sectors/track, 4 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

重启过后才能看到/dev/sdc的空间变化情况。

新建分区

[root@localhost ~]# fdisk /dev/sdc

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/sdc: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x98c391fe

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1        8192     8388592   83  Linux

Command (m for help): n

Command action

   e   extended

   p   primary partition (1-4)

p

Partition number (1-4): 2

First cylinder (8193-10240, default 8193): 

Using default value 8193

Last cylinder, +cylinders or +size{K,M,G} (8193-10240, default 10240): 

Using default value 10240

Command (m for help): p

Disk /dev/sdc: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x98c391fe

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1        8192     8388592   83  Linux

/dev/sdc2            8193       10240     2097152   83  Linux

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.

新建物理卷PV

[root@localhost ~]# pvcreate /dev/sdc2

  Physical volume "/dev/sdc2" successfully created

 

放大VG容量

[root@localhost ~]# vgextend  /dev/mapper/VolGroup02  /dev/sdc2

  Volume group "VolGroup02" successfully extended

 

放大LV容量

[root@localhost ~]# pvscan

  PV /dev/sdc1   VG VolGroup02   lvm2 [7.97 GiB / 32.00 MiB free]

  PV /dev/sdc2   VG VolGroup02   lvm2 [1.97 GiB / 1.97 GiB free]

  Total: 2 [9.94 GiB] / in use: 2 [9.94 GiB] / in no VG: 0 [0   ]

[root@localhost ~]# pvdisplay /dev/sdc2 

  --- Physical volume ---

  PV Name               /dev/sdc2

  VG Name               VolGroup02

  PV Size               2.00 GiB / not usable 32.00 MiB

  Allocatable           yes 

  PE Size               32.00 MiB

  Total PE              63

  Free PE               63

  Allocated PE          0

  PV UUID               qP1PGl-krr9-vCTY-vWgN-MsKL-rn1x-zAhmmc

[root@localhost ~]# lvextend -L +1.97G /dev/VolGroup02/LogVol00

  Rounding size to boundary between physical extents: 2.00 GiB

  Size of logical volume VolGroup02/LogVol00 changed from 7.94 GiB (254 extents) to 9.94 GiB (318 extents).

  Logical volume LogVol00 successfully resized

[root@localhost ~]# resize2fs /dev/VolGroup02/LogVol00

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/VolGroup02/LogVol00 is mounted on /u01; on-line resizing required

old desc_blocks = 32, new_desc_blocks = 40

Performing an on-line resize of /dev/VolGroup02/LogVol00 to 10420224 (1k) blocks.

The filesystem on /dev/VolGroup02/LogVol00 is now 10420224 blocks long.

[root@localhost ~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/sda2              27G  6.0G   20G  24% /

tmpfs                 5.9G     0  5.9G   0% /dev/shm

/dev/sda1             477M   32M  420M   8% /boot

/dev/sdb1              99G   60M   94G   1% /home

/dev/mapper/VolGroup02-LogVol00

                      9.7G  2.5M  9.2G   1% /u01

[root@localhost ~]#