簡單介紹:
LVM是邏輯盤卷管理(Logical Volume Manager)的簡稱,它是Linux環境下對磁盤分區進行管理的一種機制,LVM是建立在硬盤和分區之上的一個邏輯層,來提高磁盤分區管理的靈活性。通過LVM系統管理員可以輕鬆管理磁盤分區,如:將若干個磁盤分區連接爲一個整塊的卷組(volumegroup),形成一個存儲池。管理員可以在卷組上隨意創建邏輯卷組(logicalvolumes),並進一步在邏輯卷組上創建文件系統。管理員通過LVM可以方便的調整存儲卷組的大小,並且可以對磁盤存儲按照組的方式進行命名、管理和分配。
擴容方案:
①添加新硬盤,並把新硬盤通過mount掛載到指定掛載點;(比如新建一個/data目錄,把新硬盤掛載到/data下提供使用)
②添加新硬盤,通過LVM把新硬盤的空間劃給原系統盤,實現動態擴容系統盤;(也可以在虛擬機設置裏調大原有磁盤,再擴容)
此處記錄一下在centos7下方案②的操作步驟。
測試目標:
把一臺CentOS7.4虛擬機原系統磁盤擴容10G。(原系統盤30G,擴容至40G)
操作步驟:
-
虛擬機編輯設置添加一塊新硬盤
- 查看一下
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[root@server-10 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 990M 0 990M 0% /dev
tmpfs 1001M 0 1001M 0% /dev/shm
tmpfs 1001M 57M 944M 6% /run
tmpfs 1001M 0 1001M 0% /sys/fs/cgroup
/dev/mapper/centos-root 27G 5.8G 22G 22% / // 擴容後,再來看該項,作對比
/dev/sda1 1014M 154M 861M 16% /boot
tmpfs 201M 0 201M 0% /run/user/0
[root@server-10 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 30G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 29G 0 part
├─centos-root 253:0 0 27G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk // 新加的硬盤命名爲sdb,已經存在,但是還沒分區無法給系統使用
sr0 11:0 1 1024M 0 rom
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- 給新硬盤創建分區(此處就默認創建一個分區)
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[root@server-10 ~]# fdisk /dev/sdb
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.
Command (m for help): n // 添加新分區
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): // 回車,默認p,主分區
Using default response p
Partition number (1-4, default 1): // 回車,默認1
First sector (2048-20971519, default 2048): // 回車,默認起始位置
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): // 回車,默認最後位置
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): t // 更改分區格式
Selected partition 1
Hex code (type L to list all codes): L // 查看可選項
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 80 Old Minix
Hex code (type L to list all codes): 8e // 更改分區格式爲LVM
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p // 打印,查看改好的分區(blocks爲分區大小 單位爲kb)
Disk /dev/sdb: 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: 0xa6e3dd82
Device Boot Start End Blocks Id System
/dev/sdb1 2048 20971519 10484736 8e Linux LVM
Command (m for help): w // 保存
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
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- 再次查看分區,只是分區好,沒掛載沒加入系統根,無法使用
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[root@server-10 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 30G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 29G 0 part
├─centos-root 253:0 0 27G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sr0 11:0 1 1024M 0 rom
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- 把新的分區轉換爲物理卷
[root@server-10 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
- 查看現有的卷組名,這裏爲centos
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[root@server-10 ~]# vgdisplay
--- Volume group ---
VG Name centos // 這是Centos系統下默認的VG Name,RHEL系統顯示爲rhel
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 <29.00 GiB //留意該值的變化
PE Size 4.00 MiB
Total PE 7423
Alloc PE / Size 7422 / 28.99 GiB
Free PE / Size 1 / 4.00 MiB
VG UUID RNpAgN-PLQm-M4vp-E37i-fhhp-mr2z-faLm3A
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- 把轉換號的物理卷併到vg(卷組)中
[root@server-10 ~]# vgextend centos /dev/sdb1
Volume group "centos" successfully extended
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[root@server-10 ~]# 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 38.99 GiB //對比,變大了約10G
PE Size 4.00 MiB
Total PE 9982
Alloc PE / Size 7422 / 28.99 GiB
Free PE / Size 2560 / 10.00 GiB
VG UUID RNpAgN-PLQm-M4vp-E37i-fhhp-mr2z-faLm3A
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- 查看邏輯卷,默認系統分了2個,選擇對應邏輯卷路徑
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[root@server-10 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap //系統默認分了2G給swap,不用管
LV Name swap
VG Name centos
LV UUID w8yxWk-Qrth-x16P-jVg3-1haX-lZUH-0r1SkV
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-03-21 02:10:16 +0800
LV Status available
#open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/centos/root // 後面擴展該邏輯卷,記住該路徑
LV Name root
VG Name centos
LV UUID ECEWl4-0AEW-W1Tn-acE2-GLpe-NxeD-v16tGb
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-03-21 02:10:16 +0800
LV Status available
#open 1
LV Size 26.99 GiB
Current LE 6910
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
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- 給邏輯卷擴展空間
[root@server-10 ~]# lvextend /dev/centos/root /dev/sdb1
Size of logical volume centos/root changed from 26.99 GiB (6910 extents) to <36.99 GiB (9469 extents).
Logical volume centos/root successfully resized.
- 寫入文件系統,使擴容生效。
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[root@server-10 ~]# xfs_growfs /dev/mapper/centos-root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=1768960 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=7075840, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=3455, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 7075840 to 9696256
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如果是ext系統,可以使用resize2fs命令替換xfs_growfs命令。
- 檢查擴容效果
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[root@server-10 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 990M 0 990M 0% /dev
tmpfs 1001M 0 1001M 0% /dev/shm
tmpfs 1001M 57M 944M 6% /run
tmpfs 1001M 0 1001M 0% /sys/fs/cgroup
/dev/mapper/centos-root 37G 5.8G 32G 16% /
/dev/sda1 1014M 154M 861M 16% /boot
tmpfs 201M 0 201M 0% /run/user/0
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