lvm扩容root目录实战
2020-10-17 本文已影响0人
小黑佬
很无奈，今天有需求要扩展pve vm的root空间，安装linux centos7系统使用了默认的lvm格式。
先简单说说lvm原理，具体流程是PV -> VG -> LV，弄懂什么是PV VG LV基本就可以了。
image.png
物理卷： 也就是图中第二层，是通过物理分区创建而来，与物理分区一一对应。创建为物理卷后，则可以将物理卷合并为一个大的卷组。通过命令pvdisplay 查看物理卷
卷组： 也就是图中第三层，卷组是不同的物理卷合并而成，可以将所有物理卷的大小整合成一个大的卷组，相当于一个大的整合的逻辑磁盘，然后在卷组中就可以根据需求划分逻辑卷。通过命令vgdisplay 查看卷组。
逻辑卷： 也就是图中最顶层，逻辑卷是从卷组中划分出来的，相当于逻辑分区，此逻辑卷就可以直接格式化挂载到目录，就可以直接使用了。通过命令lvdisplay 查看逻辑卷。
sda -> pv1
sdb -> pv2 pv3
sdc -> pv4 pv5
p1 pv2 pv3 ->lv2
p4 p5 -> lv2
添加一块物理硬盘
Disk /dev/sdb: 536.9 GB
$ fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x00044ae5
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
Disk /dev/mapper/centos-root: 50.5 GB, 50457477120 bytes, 98549760 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: 2147 MB, 2147483648 bytes, 4194304 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/sdb: 536.9 GB, 536870912000 bytes, 1048576000 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
对新盘分区
使用 fdisk 命令对新盘进行分区，这里建立了一个主分区 /dev/sdb1 ，大小 500GB，最后使用 partprobe 命令重新读取分区表，命令记录如下：
#进去分区
$ 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.
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x79bd83e1.
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
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
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-1048575999, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-1048575999, default 1048575999):
Using default value 1048575999
Partition 1 of type Linux and of size 500 GiB is set
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): L
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
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
#重新读取分区信息表
$ partprobe
Warning: Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only.
#验证是否已经分区好了,留意 ID 83 和8e
$ fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x00044ae5
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
Disk /dev/mapper/centos-root: 50.5 GB, 50457477120 bytes, 98549760 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: 2147 MB, 2147483648 bytes, 4194304 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/sdb: 536.9 GB, 536870912000 bytes, 1048576000 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: 0x79bd83e1
Device Boot Start End Blocks Id System
/dev/sdb1 2048 1048575999 524286976 8e Linux LVM
创建物理卷（PV）
$ pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID YrKREU-HMSO-0DtT-HR9I-M3UB-oJ29-F2PCAV
$ pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
$ pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID YrKREU-HMSO-0DtT-HR9I-M3UB-oJ29-F2PCAV
"/dev/sdb1" is a new physical volume of "<500.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size <500.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID QHHlhW-paNf-rPiR-PQWK-MDnv-oM52-K8I69p
将PV加入卷组（VG）
#查看卷组，可用 PE 为 1
$ 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 <49.00 GiB
PE Size 4.00 MiB
Total PE 12543
Alloc PE / Size 12542 / 48.99 GiB
Free PE / Size 1 / 4.00 MiB
VG UUID Z50sk6-ev4r-1eKd-Iq2B-NKTf-MgyA-6gJJmK
# 将新的 PV 加入 centos 组卷
$ vgextend centos /dev/sdb1
Volume group "centos" successfully extended
# 查看卷组，可用 PE 为 128000了
$ 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 548.99 GiB
PE Size 4.00 MiB
Total PE 140542
Alloc PE / Size 12542 / 48.99 GiB
Free PE / Size 128000 / 500.00 GiB
VG UUID Z50sk6-ev4r-1eKd-Iq2B-NKTf-MgyA-6gJJmK
创建逻辑卷（LV）
#此处省略，因为我们这次不是创建新的逻辑卷，而是扩容root目录
逻辑卷（LV）扩容 (扩容root目录)
#查看逻辑卷
$ lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID mHVwAP-mwnb-9JeJ-lUX0-FsBp-D12u-eWQXA3
LV Write Access read/write
LV Creation host, time localhost, 2020-08-14 10:40:03 +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
LV Name root
VG Name centos
LV UUID UPgbYl-lqzs-CK2d-9tO8-Hl2T-sdxe-aqZ2eP
LV Write Access read/write
LV Creation host, time localhost, 2020-08-14 10:40:04 +0800
LV Status available
# open 1
LV Size 46.99 GiB
Current LE 12030
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
# 扩容root目录
$ lvextend -l +100%FREE /dev/centos/root
Size of logical volume centos/root changed from 46.99 GiB (12030 extents) to 546.99 GiB (140030 extents).
Logical volume centos/root successfully resized.
# xfs_growfs 对扩容后的 LV 进行 xfs 格式大小调整，Centos 6 使用 resize2fs
$ xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=3079680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=12318720, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=6015, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 12318720 to 143390720
# 查看卷组vg信息，可用PE已经为0了，全部分配了出去
$ vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 5
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 548.99 GiB
PE Size 4.00 MiB
Total PE 140542
Alloc PE / Size 140542 / 548.99 GiB
Free PE / Size 0 / 0
VG UUID Z50sk6-ev4r-1eKd-Iq2B-NKTf-MgyA-6gJJmK
# 查看逻辑卷信息 ，root 容量已经为500多G
$ lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID mHVwAP-mwnb-9JeJ-lUX0-FsBp-D12u-eWQXA3
LV Write Access read/write
LV Creation host, time localhost, 2020-08-14 10:40:03 +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
LV Name root
VG Name centos
LV UUID UPgbYl-lqzs-CK2d-9tO8-Hl2T-sdxe-aqZ2eP
LV Write Access read/write
LV Creation host, time localhost, 2020-08-14 10:40:04 +0800
LV Status available
# open 1
LV Size 546.99 GiB
Current LE 140030
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
查看挂载信息
$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs tmpfs 7.8G 8.5M 7.8G 1% /run
tmpfs tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 547G 7.8G 540G 2% /
/dev/sda1 xfs 1014M 150M 865M 15% /boot
tmpfs tmpfs 1.6G 0 1.6G 0% /run/user/0
