LVM磁碟建立與擴容

阿新 • • 發佈：2021-12-06

以虛擬機器為例

1、在虛擬機器上新增新磁碟，點選虛擬機器→設定->新增，最後如下圖。

2、進入系統fdisk -l，檢視當前磁碟資訊

[root@master shell]# fdisk -l
 
Disk /dev/sda: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000af178
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    20971519     9436160   8e  Linux LVM
 
Disk /dev/mapper/centos-root: 8585 MB, 8585740288 bytes, 16769024 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
 
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
[root@master shell]#

發現沒有讀到我們新新增的磁碟，我們重啟下虛擬機器。

如果不想重啟，或者是生產上的伺服器，不允許重啟，可以使用partprobe，線上更新分割槽表。

# partprobe線上更新分割槽資訊表，獲取最新的磁碟資訊
[root@master ~]# partprobe

重新使用fdisk -l命令檢視，發現多了一塊21.5GB的/dev/sdb磁碟

# fdisk -l 重新檢視一下
[root@master ~]# df -Th
Filesystem              Type      Size  Used Avail Use% Mounted on
devtmpfs                devtmpfs  475M     0  475M   0% /dev
tmpfs                   tmpfs     487M     0  487M   0% /dev/shm
tmpfs                   tmpfs     487M  7.5M  479M   2% /run
tmpfs                   tmpfs     487M     0  487M   0% /sys/fs/cgroup
/dev/mapper/centos-root xfs       8.0G  4.8G  3.3G  60% /
/dev/sda1               xfs      1014M  167M  848M  17% /boot
tmpfs                   tmpfs      98M     0   98M   0% /run/user/0
[root@master ~]# fdisk -l
 
Disk /dev/sda: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000af178
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    20971519     9436160   8e  Linux LVM
 
Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
 
Disk /dev/mapper/centos-root: 8585 MB, 8585740288 bytes, 16769024 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
 
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

3、fdisk在新的磁碟上建立分割槽

[root@master ~]# fdisk /dev/sdb     # 注意，這裡的sdb是不帶數字的
Welcome to fdisk (util-linux 2.23.2).
 
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
 
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xe1f69387.
 
Command (m for help): n       # new新建分割槽
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p     # 選擇主分割槽
Partition number (1-4, default 1): 1       # 分割槽編號，直接回車，選擇預設的1就好
First sector (2048-41943039, default 2048):         # 設定起始扇區，直接回車，選擇預設的
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039):    # 設定結束扇區，直接回車，預設選擇到磁碟的最後一個扇區。
Using default value 41943039             # 預設分割槽的容量就是整個磁碟的容量
Partition 1 of type Linux and of size 20 GiB is set
 
Command (m for help): p        # print列印當前設定好的磁碟資訊（注意，此時還沒物理生效）
 
Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xe1f69387
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    41943039    20970496   83  Linux
 
Command (m for help): t        # 輸入t，修改磁碟格式為LVM格式
Selected partition 1
Hex code (type L to list all codes): 8e     # 輸入8e，8e代表LVM格式
Changed type of partition 'Linux' to 'Linux LVM'
 
Command (m for help): p       # 再次列印磁碟資訊
 
Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xe1f69387
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    41943039    20970496   8e  Linux LVM
 
Command (m for help): w      # w開始儲存設定的磁碟分割槽資訊，此時才是真正作用生效了。
The partition table has been altered!
 
Calling ioctl() to re-read partition table.
Syncing disks.

4、建立pv

建立LVM概念中的物理卷。

注意：這裡要選帶數字編號的磁碟，這裡的/dev/sdb1就是上面我們用fdisk建立好的磁碟分割槽，1表示我們的分割槽編號，上面設定的是1，所以這裡就是sdb1

[root@master ~]# pvscan     # 檢視當前系統上的物理卷資訊
  PV /dev/sda2   VG centos          lvm2 [<9.00 GiB / 0    free]
  Total: 1 [<9.00 GiB] / in use: 1 [<9.00 GiB] / in no VG: 0 [0   ]
[root@master ~]# pvcreate /dev/sdb1     # 建立物理卷，注意這裡的磁碟尾號sdb1必須帶數字
  Physical volume "/dev/sdb1" successfully created.
[root@master ~]# pvscan
  PV /dev/sda2   VG centos          lvm2 [<9.00 GiB / 0    free]
  PV /dev/sdb1                      lvm2 [<20.00 GiB]
  Total: 2 [<29.00 GiB] / in use: 1 [<9.00 GiB] / in no VG: 1 [<20.00 GiB]

5、將pv加入vg組，擴容vg

pv是物理卷，vg是卷組，多個pv組成一個vg，然後vg裡面去構建邏輯卷組lv

如果系統沒有vg，則建立vg組。

[root@master ~]# vgdisplay
[root@master ~]# vgscan
  Reading volume groups from cache.
# vgcreate 後面可以接多個磁碟，比如vgcreate vgdata /dev/xvde1 /dev/xvde2，因為這裡只有一塊，所以就用一個
[root@master ~]# vgcreate vgdata /dev/xvde1   # 建立vg，vg名字設定為vgdata，/dev/xvde1是我們上面建立的pv卷的名字
  Volume group "vgdata" successfully created
[root@master ~]# vgscan
  Reading volume groups from cache.
  Found volume group "vgdata" using metadata type lvm2
[root@master ~]# vgdisplay
  --- Volume group ---
  VG Name               vgdata
  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               <300.00 GiB
  PE Size               4.00 MiB
  Total PE              76799
  Alloc PE / Size       0 / 0  
  Free  PE / Size       76799 / <300.00 GiB
  VG UUID               bY9vpW-ALyF-YDxB-WCjj-Tlvg-04Jp-DWXdkm
    
[root@master ~]#

如果有vg，則擴容

[root@master ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  System ID            
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <9.00 GiB
  PE Size               4.00 MiB
  Total PE              2303
  Alloc PE / Size       2303 / <9.00 GiB
  Free  PE / Size       0 / 0  
  VG UUID               YSauT8-zhj2-05Yc-c4rb-VNqs-OjrX-ZB8eeE
    
[root@master ~]# vgextend centos /dev/sdb1   # centos是原來就已經存在的卷組名字，/dev/sdb1是我們剛剛建立的pv名字
  Volume group "centos" successfully extended
[root@master ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  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               28.99 GiB
  PE Size               4.00 MiB
  Total PE              7422
  Alloc PE / Size       2303 / <9.00 GiB
  Free  PE / Size       5119 / <20.00 GiB
  VG UUID               YSauT8-zhj2-05Yc-c4rb-VNqs-OjrX-ZB8eeE

6、擴容LV

如果LV邏輯卷不存在，則建立

[root@yzjgxh2529638940 ~]# lvcreate -n lvdata -L 300G vgdata
  Volume group "vgdata" has insufficient free space (76799 extents): 76800 required.
# 一般無法用到300G,所以稍微小一點就好了
[root@yzjgxh2529638940 ~]# lvcreate -n lvdata -L 299G vgdata
  Logical volume "lvdata" created.
[root@yzjgxh2529638940 ~]# lvscan
  ACTIVE            '/dev/vgdata/lvdata' [299.00 GiB] inherit
[root@yzjgxh2529638940 ~]#
# 格式化該邏輯分割槽
[root@yzjgxh2529638940 ~]# mkfs.xfs /dev/vgdata/lvdata
meta-data=/dev/vgdata/lvdata     isize=512    agcount=4, agsize=19595264 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=78381056, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=38272, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@yzjgxh2529638940 ~]#

如果LV邏輯卷存在，則擴容

[root@master ~]# lvscan
  ACTIVE            '/dev/centos/swap' [1.00 GiB] inherit
  ACTIVE            '/dev/centos/root' [<8.00 GiB] inherit
[root@master ~]# lvextend -L +19.5G /dev/centos/root
  Size of logical volume centos/root changed from <8.00 GiB (2047 extents) to <27.50 GiB (7039 extents).
  Logical volume centos/root successfully resized.

7、resize使檔案系統生效（重要）

[root@master ~]# df -Th
Filesystem              Type      Size  Used Avail Use% Mounted on
devtmpfs                devtmpfs  475M     0  475M   0% /dev
tmpfs                   tmpfs     487M     0  487M   0% /dev/shm
tmpfs                   tmpfs     487M  7.5M  479M   2% /run
tmpfs                   tmpfs     487M     0  487M   0% /sys/fs/cgroup
/dev/mapper/centos-root xfs       8.0G  4.8G  3.3G  60% /
/dev/sda1               xfs      1014M  167M  848M  17% /boot
tmpfs                   tmpfs      98M     0   98M   0% /run/user/0
# ext3,ext4使用resize2fs
[root@master ~]# resize2fs /dev/centos/root
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open /dev/centos/root
Couldn't find valid filesystem superblock.
# 這裡需要擴容的是xfs，所以用xfs_growfs命令
[root@master ~]# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=524032 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=2096128, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 2096128 to 7207936
[root@master ~]# df -Th
Filesystem              Type      Size  Used Avail Use% Mounted on
devtmpfs                devtmpfs  475M     0  475M   0% /dev
tmpfs                   tmpfs     487M     0  487M   0% /dev/shm
tmpfs                   tmpfs     487M  7.5M  479M   2% /run
tmpfs                   tmpfs     487M     0  487M   0% /sys/fs/cgroup
/dev/mapper/centos-root xfs        28G  4.8G   23G  18% /
/dev/sda1               xfs      1014M  167M  848M  17% /boot
tmpfs                   tmpfs      98M     0   98M   0% /run/user/0

8、掛載

# 建立掛載的目錄
[root@yzjgxh2529638940 ~]# mkdir /data
# 開始掛載
[root@yzjgxh2529638940 ~]# mount /dev/vgdata/lvdata /data/
[root@yzjgxh2529638940 ~]# df -Th
Filesystem                Type      Size  Used Avail Use% Mounted on
/dev/xvda2                xfs        36G  2.1G   34G   6% /
devtmpfs                  devtmpfs   32G     0   32G   0% /dev
tmpfs                     tmpfs      32G   24K   32G   1% /dev/shm
tmpfs                     tmpfs      32G   18M   32G   1% /run
tmpfs                     tmpfs      32G     0   32G   0% /sys/fs/cgroup
tmpfs                     tmpfs     6.3G     0  6.3G   0% /run/user/0
/dev/mapper/vgdata-lvdata xfs       299G   33M  299G   1% /data
# 加入開機自動掛載
[root@yzjgxh2529638940 ~]# vim /etc/fstab
 
#
# /etc/fstab
# Created by anaconda on Thu May  9 01:56:05 2019
#
# 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=a83f4fdc-2ea1-4fec-a1e2-a42016ce0afe /                       xfs     defaults        0 0
UUID=9e33bd6f-c68c-41c7-95c8-703f4fe8c3d4 swap                    swap    defaults        0 0
/dev/vgdata/lvdata                        /data                   xfs     defaults        0 0

到此，LVM擴容完成。