CentOS7.x系统根目录分区扩容
说明：系统版本为 Linux version 3.10.0-327.el7.x86_64
step1. 查看现有磁盘信息，可以看出根分区有45G
[root@DEV-CMDB-DB02 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos_mb--centos7-root 45G 9.8G 35G 23% /
devtmpfs 5.9G 0 5.9G 0% /dev
tmpfs 5.9G 84K 5.9G 1% /dev/shm
tmpfs 5.9G 8.9M 5.9G 1% /run
tmpfs 5.9G 0 5.9G 0% /sys/fs/cgroup
/dev/sda1 497M 142M 356M 29% /boot
tmpfs 1.2G 16K 1.2G 1% /run/user/42
tmpfs 1.2G 0 1.2G 0% /run/user/0
step2. 查看新增加的磁盘信息
[root@DEV-CMDB-DB02 ~]# 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: 0x000e0945
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 104857599 51915776 8e Linux LVM
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 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_mb--centos7-root: 47.7 GB, 47747956736 bytes, 93257728 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_mb--centos7-swap: 5368 MB, 5368709120 bytes, 10485760 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
step3. 根据以上信息，对新增加的磁盘进行分区
[root@DEV-CMDB-DB02 ~]# 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 0x232defba.
Command (m for help): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 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: 0x232defba
Device Boot Start End Blocks Id System
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): 1
First sector (2048-209715199, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199):
Using default value 209715199
Partition 1 of type Linux and of size 100 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): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 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: 0x232defba
Device Boot Start End Blocks Id System
/dev/sdb1 2048 209715199 104856576 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
step4. 创建物理卷
[root@DEV-CMDB-DB02 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created
step5. 查看物理卷信息
[root@DEV-CMDB-DB02 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos_mb-centos7
PV Size 49.51 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12674
Free PE 10
Allocated PE 12664
PV UUID 8WbgjB-T1Lf-kqUD-qPFw-UwJu-B9Lc-GAUTUB
"/dev/sdb1" is a new physical volume of "100.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 100.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID HOknRs-TnMy-wtfX-sGqD-5RK9-dk9q-ze13fj
[root@DEV-CMDB-DB02 ~]# vgdisplay
--- Volume group ---
VG Name centos_mb-centos7
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 49.51 GiB
PE Size 4.00 MiB
Total PE 12674
Alloc PE / Size 12664 / 49.47 GiB
Free PE / Size 10 / 40.00 MiB
VG UUID aN2D2P-Rk1y-wGFz-5l2I-5CcD-7s88-Z8czc7
step6. 将新增加的分区/dev/sdb1加入到根目录分区centos_mb-centos7中
[root@DEV-CMDB-DB02 ~]# vgextend centos_mb-centos7 /dev/sdb1
Volume group "centos_mb-centos7" successfully extended
step7. 重新查看卷组信息
[root@DEV-CMDB-DB02 ~]# vgdisplay
--- Volume group ---
VG Name centos_mb-centos7
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 149.50 GiB
PE Size 4.00 MiB
Total PE 38273
Alloc PE / Size 12664 / 49.47 GiB
Free PE / Size 25609 / 100.04 GiB
VG UUID aN2D2P-Rk1y-wGFz-5l2I-5CcD-7s88-Z8czc7
step9. 进行卷扩容
[root@DEV-CMDB-DB02 ~]# lvextend -l +100%FREE /dev/mapper/centos_mb--centos7-root
Size of logical volume centos_mb-centos7/root changed from 44.47 GiB (11384 extents) to 144.50 GiB (36993 extents).
Logical volume root successfully resized.
step10. 调整卷分区大小
[root@DEV-CMDB-DB02 ~]# xfs_growfs /dev/mapper/centos_mb--centos7-root
meta-data=/dev/mapper/centos_mb--centos7-root isize=256 agcount=4, agsize=2914304 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=11657216, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=5692, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 11657216 to 37880832
最后，查看磁盘信息可以看出根目录分区大小已成功扩容
[root@DEV-CMDB-DB02 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos_mb--centos7-root 145G 9.8G 135G 7% /
devtmpfs 5.9G 0 5.9G 0% /dev
tmpfs 5.9G 84K 5.9G 1% /dev/shm
tmpfs 5.9G 8.9M 5.9G 1% /run
tmpfs 5.9G 0 5.9G 0% /sys/fs/cgroup
/dev/sda1 497M 142M 356M 29% /boot
tmpfs 1.2G 16K 1.2G 1% /run/user/42
tmpfs 1.2G 0 1.2G 0% /run/user/0
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
centos7根分区扩容(亲测有效)
基本的逻辑卷管理概念：
PV（Physical Volume）- 物理卷
物理卷在逻辑卷管理中处于最底层，它可以是实际物理硬盘上的分区，也可以是整个物理硬盘，也可以是raid设备。
VG（Volumne Group）- 卷组
卷组建立在物理卷之上，一个卷组中至少要包括一个物理卷，在卷组建立之后可动态添加物理卷到卷组中。一个逻辑卷管理系统工程中可以只有一个卷组，也可以拥有多个卷组。
LV（Logical Volume）- 逻辑卷
逻辑卷建立在卷组之上，卷组中的未分配空间可以用于建立新的逻辑卷，逻辑卷建立后可以动态地扩展和缩小空间。系统中的多个逻辑卷可以属于同一个卷组，也可以属于不同的多个卷组
PE（Physical Extent）- 物理块
LVM 默认使用4MB的PE区块，而LVM的LV最多仅能含有65534个PE (lvm1 的格式)，因此默认的LVM的LV最大容量为4M*65534/(1024M/G)=256G。PE是整个LVM 最小的储存区块，也就是说，其实我们的资料都是由写入PE 来处理的。简单的说，这个PE 就有点像文件系统里面的block 大小。所以调整PE 会影响到LVM 的最大容量！不过，在 CentOS 6.x 以后，由于直接使用 lvm2 的各项格式功能，因此这个限制已经不存在了。
一、增加新硬盘并分区
[root@test ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/centos_test2-root 28G 14G 15G 48% /
devtmpfs 1.9G 0 1.9G 0%
/dev/dev/xvda1 497M 267M 231M 54% /boot
[root@test ~]# fdisk -l #新添加一块100G硬盘并查看是否已有新磁盘/dev/sdb
[root@test ~]# fdisk /dev/sdb #对新磁盘进行分区
在fdisk的交互模式中，依次输入：
n --创建新分区
p --创建主分区
分区号 --默认分区编号 1
<回车> --默认起始扇区位置。
<回车> --默认结束扇区位置。 如果要把100G全部分给这个分区，直接两次回车。如果分60G输入+60G
t --修改分区类型
8e --修改为LVM
p --打印分区查看类型
w --保存
这样就把整个磁盘分成了一个区。再看一下现有磁盘情况：
[root@test ~]# fdisk -l
已经多出了一个新分区：
Device Boot Start End Blocks Id System
/dev/sdb1 2048 6291455 3144704 8e Linux
二、初始化分区,加入卷组
1.创建PV
[root@test ~]#pvcreate /dev/sdb1
有可能会提示是否擦除xfs签名，我选了y：
WARNING: xfs signature detected on /dev/sdb1 at offset 0. Wipe it? [y/n] y
Wiping xfs signature on /dev/sdb1.
Physical volume "/dev/sdb1" successfully created
查看结果：
[root@test ~]#pvdisplay
2.查看卷组,并将初始化的分区加入到虚拟卷组
为卷组"centos"添加新的物理卷sdb1增加卷组的容量."centos"是vgdisplay命令查到的卷分组名：
[root@test ~]#vgextend centos /dev/sdb1
下面查看一下逻辑卷：
# lvdisplay
可以看到/dev/centos/root目前的LV Size是1000MiB。
下面扩展逻辑卷/dev/centos/root:
# lvextend -L +60G /dev/centos/root
注：+60G是我们新增加的分区大小。
扩展后，还要执行一步：
# xfs_growfs /dev/centos/root
将文件系统扩大。
fdisk /dev/sdb
fdisk -l
vgdisplay -v
fdisk -l
pvcreate /dev/xvdb1
pvdisplay
vgextend centos /dev/sdb1
lvextend -L +20G /dev/centos/root
xfs_growfs /dev/mapper/centos-root
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