LVM擴容案例

時間 2020-03-20

標籤 lvm 擴容案例欄目 Linux 简体版

原文原文鏈接

測試數據

cd / && dd if=/dev/zero of=file bs=1M count=10000
將磁盤變大的測試命令. 生產環境不要用. 這只是用於測試擴容後的效果

LVM基礎命令:

pvdisplay 查看檢查pv
pvremove /dev/sdb    #清除一個pv
vgremove [vg名]      #清除一個vg
lvremove [lv名]      #清除一個lv

fdisk -l  檢查磁盤
df -h     檢查所有磁盤大小
df -Th    檢查磁盤大小和分區格式類型
pvdisplay 檢查pv
vgdisplay 檢查vg
lvdisplay 檢查lv

0. 添加磁盤後須要進行掃描識別

echo "- - -" > /sys/class/scsi_host/host0/scan
echo "- - -" > /sys/class/scsi_host/host1/scan
echo "- - -" > /sys/class/scsi_host/host2/scan

1. 檢查當前磁盤

[root@localhost /]# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   40G  9.6G   31G  24% /
devtmpfs                 982M     0  982M   0% /dev
tmpfs                    993M     0  993M   0% /dev/shm
tmpfs                    993M  8.7M  984M   1% /run
tmpfs                    993M     0  993M   0% /sys/fs/cgroup
/dev/sda1                197M  103M   95M  53% /boot
tmpfs                    199M     0  199M   0% /run/user/0

注意: /dev/mapper/centos-root 是邏輯卷的路徑.node

2. 檢查pv [ pvdisplay ]

[root@localhost /]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               centos
  PV Size               19.80 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              5069
  Free PE               0
  Allocated PE          5069
  PV UUID               4YLVja-jT6q-FphK-3E60-5Qde-Z3gw-zLpcYT
   
  --- Physical volume ---
  PV Name               /dev/sdb1
  VG Name               centos
  PV Size               <20.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               0
  Allocated PE          5119
  PV UUID               SBfuCJ-tli0-Mi2U-wO3w-eQub-0v36-0XkQBw

3. 檢查vg

[root@localhost ~]# vgdisplay 
  --- Volume group ---
  VG Name               centos
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               19.80 GiB
  PE Size               4.00 MiB
  Total PE              5069
  Alloc PE / Size       5069 / 19.80 GiB
  Free  PE / Size       0 / 0   
  VG UUID               lkJhAi-7Df5-0K69-LYV4-exS2-ZqE1-FYMyIG

4. 檢查lv

[root@localhost ~]# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                tUUfhM-dDfU-Aw6K-tiAj-wyqf-cvbl-FcLOxj
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2019-11-22 04:12:42 +0800
  LV Status              available
  # open                 1
  LV Size                19.80 GiB
  Current LE             5069
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

擴容思路

1. 加入磁盤
2. 檢查磁盤id 修改爲須要擴容的磁盤ID一致,經過fdisk -l 能夠查看ID
[root@localhost ~]# fdisk -l /dev/sda
.....
 Device   Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      411647      204800   83  Linux
/dev/sda2          411648    41943039    20765696   8e  Linux LVM

能夠看到ID是 8e LVM,因此新加入的磁盤也須要改成 8e

3. 建立物理卷 pv 
4. pv加入vg卷組
5. 擴容磁盤
6. 格式化磁盤
7. 結束

擴容磁盤

1. 添加磁盤

xxx 本身意淫把linux

2. 掃描新增磁盤

掃描:
 echo "- - -" > /sys/class/scsi_host/host0/scan
 echo "- - -" > /sys/class/scsi_host/host1/scan
 echo "- - -" > /sys/class/scsi_host/host2/scan

3. 分區更改磁盤格式爲LVM:

## 建立分區並修改磁盤格式爲 [8e]:
fdisk /dev/sdc [操做新磁盤]
 
[root@localhost /]# fdisk /dev/sdc
    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 0xc7dec5f2.
    
    Command (m for help): n    #####-----建立分區
    Partition type:
    p   primary (0 primary, 0 extended, 4 free)
    e   extended
    Select (default p): 
    Using default response p   #####-----建立默認主分區[主分區總共就只能分出4個超過4個須要建立擴展分區]
    Partition number (1-4, default 1): 
    First sector (2048-62914559, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-62914559, default 62914559):
    Using default value 62914559
    Partition 1 of type Linux and of size 30 GiB is set
    
    Command (m for help): t       #####-----更改磁盤格式 
    Selected partition 1
    Hex code (type L to list all codes): 8e        #####-----更改成8e
    Changed type of partition 'Linux' to 'Linux LVM'
    
    
    Command (m for help): p     ### 查看一下是否是 8e

    Disk /dev/sdc: 32.2 GB, 32212254720 bytes, 62914560 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: 0xc7dec5f2
    
    Device Boot      Start         End        Blocks    Id  System
    /dev/sdc1            2048    62914559    31456256   8e  Linux LVM    #確實已是8e了

    
    Command (m for help): w     #####-----保存
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.
    
    ##分區和磁盤格式更改完畢

4. 建立物理卷組:

# 建立物理卷 pvcreate /dev/sdc1
    [root@localhost /]# pvcreate /dev/sdc1
    Physical volume "/dev/sdc1" successfully created.
    
# 物理卷加入刀 centos 這個 vg 中
[root@localhost /]# vgextend centos  /dev/sdc1
  Volume group "centos" successfully extended

5. 檢查PE個數

vgdisplay 
 
 [root@localhost /]# vgdisplay 
    --- Volume group ---
    VG Name               centos
    System ID             
    Format                lvm2
    Metadata Areas        3
    Metadata Sequence No  5
    VG Access             read/write
    VG Status             resizable
    MAX LV                0
    Cur LV                1
    Open LV               1
    Max PV                0
    Cur PV                3
    Act PV                3
    VG Size               69.79 GiB
    PE Size               4.00 MiB
    Total PE              17867
    Alloc PE / Size       10188 / <39.80 GiB
    Free  PE / Size       7679 / <30.00 GiB         ###這是剩餘PE數量, 7679,也是新增的30G磁盤,7679個PE
    VG UUID               lkJhAi-7Df5-0K69-LYV4-exS2-ZqE1-FYMyIG

6. 擴容磁盤:

#先看目前磁盤狀況:
 [root@localhost /]# df -h
 Filesystem               Size  Used Avail Use% Mounted on
 /dev/mapper/centos-root   40G  9.6G   31G  24% /          ## 31G.
 devtmpfs                 982M     0  982M   0% /dev
 tmpfs                    993M     0  993M   0% /dev/shm
 tmpfs                    993M  8.7M  984M   1% /run
 tmpfs                    993M     0  993M   0% /sys/fs/cgroup
 /dev/sda1                197M  103M   95M  53% /boot
 tmpfs                    199M     0  199M   0% /run/user/0


# 擴容並格式化磁盤:
lvresize -r -l +7679  /dev/centos/root
 
#結果: 
[root@localhost /]# lvresize -r -l +7679  /dev/centos/root
      Size of logical volume centos/root changed from <39.80 GiB (10188 extents) to 69.79 GiB (17867 extents).
      Logical volume centos/root successfully resized.
  meta-data=/dev/mapper/centos-root isize=512    agcount=9, agsize=1297664 blks
           =                       sectsz=512   attr=2, projid32bit=1
           =                       crc=1        finobt=0 spinodes=0
  data     =                       bsize=4096   blocks=10432512, 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 10432512 to 18295808
  
 #這是將全部PE都劃分給了 /dev/centos/root , 其中 -r 是劃分的同時格式化這塊新磁盤,並加入到 該分區中.
 #也就是本身先格式化後擴容給/dev/centos/root 磁盤 . 
 #這種方法是按照PE個數來劃分磁盤的, 磁盤總大小就是   磁盤總大小 = PE個數 * PE size

7. 檢查磁盤現有狀況:

# 查看現有磁盤大小:
  [root@localhost /]# df -h
  Filesystem               Size  Used Avail Use% Mounted on
  /dev/mapper/centos-root   70G  9.6G   61G  14% /        ##-----擴容成功,磁盤從 32%降低到了14 ,大小也變成了 61G
  devtmpfs                 982M     0  982M   0% /dev
  tmpfs                    993M     0  993M   0% /dev/shm
  tmpfs                    993M  8.7M  984M   1% /run
  tmpfs                    993M     0  993M   0% /sys/fs/cgroup
  /dev/sda1                197M  103M   95M  53% /boot
  tmpfs                    199M     0  199M   0% /run/user/0
  
  ## 31G+擴容給的 30G一共是 61G 所有劃分正確.

查看磁盤UUID:

[root@localhost ~]# blkid 
/dev/sda1: UUID="cb322c86-f37a-49e8-86a0-924d9b0c719e" TYPE="xfs" 
/dev/sda2: UUID="4YLVja-jT6q-FphK-3E60-5Qde-Z3gw-zLpcYT" TYPE="LVM2_member" 
/dev/sdb1: UUID="SBfuCJ-tli0-Mi2U-wO3w-eQub-0v36-0XkQBw" TYPE="LVM2_member" 
/dev/sdc1: UUID="Z7K8RO-denr-cyn8-sCjb-9HMa-Pu3I-ciK3kt" TYPE="LVM2_member" 
/dev/sr0: UUID="2017-09-06-10-51-00-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/mapper/centos-root: UUID="e3508edd-30c0-4e7d-9d8f-622c8dbd174e" TYPE="xfs"

擴容完成.centos

PDF文檔:

lvm01.pdfapp

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