作者：IT邦德
中国DBA联盟(ACDU)成员，目前从事DBA及程序编程
（Web\java\Python）工作，主要服务于生产制造
现拥有 Oracle 11g OCP/OCM、
Mysql、Oceanbase（OBCA）认证
分布式TBase\TDSQL数据库、国产达梦数据库以及红帽子认证
从业8年DBA工作，在数据库领域有丰富的经验
B站主播Oracle、Mysql、PG实战课程，请搜索：jeames007
擅长Oracle数据库运维开发，备份恢复，安装迁移，性能优化、故障应急处理等。
前言
近日服务器的根目录快满了，仔细一查看使用的是逻辑卷，本文总结了以下扩展分区的方法， 本次扩展的是根分区1.分区大小
[root@rhel76 ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/rhel-root xfs 30G 4.3G 26G 15% /
devtmpfs devtmpfs 2.0G 0 2.0G 0% /dev
tmpfs tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs tmpfs 2.0G 13M 2.0G 1% /run
tmpfs tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup
/dev/sda1 xfs 950M 164M 786M 18% /boot
/dev/mapper/rhel-u01 xfs 28G 33M 28G 1% /u01
tmpfs tmpfs 394M 4.0K 394M 1% /run/user/42
tmpfs tmpfs 394M 48K 394M 1% /run/user/0
可以看出/分区已经明明显不足，需要扩展
2.裸盘划分
[root@rhel76 ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 28 23:34 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 28 23:34 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 28 23:34 /dev/sda2
brw-rw----. 1 root disk 8, 16 Nov 28 23:34 /dev/sdb
[root@rhel76 ~]# fdisk /dev/sdb
[root@rhel76 ~]# 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 0xa1773dc6.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1): 1
First sector (2048-41943039, default 2048):
Using default value 2048
Last sector, +sectors or +size{
K,M,G} (2048-41943039, default 41943039):
Using default value 41943039
Partition 1 of type Linux and of size 20 GiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
[root@rhel76 ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 28 23:34 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 28 23:34 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 28 23:34 /dev/sda2
brw-rw----. 1 root disk 8, 16 Nov 28 23:49 /dev/sdb
brw-rw----. 1 root disk 8, 17 Nov 28 23:49 /dev/sdb1
[root@rhel76 ~]# fdisk -l | grep dev
Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
/dev/sdb1 2048 41943039 20970496 83 Linux
Disk /dev/sda: 64.4 GB, 64424509440 bytes, 125829120 sectors
/dev/sda1 * 2048 1953791 975872 83 Linux
/dev/sda2 1953792 125829119 61937664 8e Linux LVM
Disk /dev/mapper/rhel-root: 31.4 GB, 31415336960 bytes, 61358080 sectors
Disk /dev/mapper/rhel-swap: 2000 MB, 2000683008 bytes, 3907584 sectors
Disk /dev/mapper/rhel-u01: 30.0 GB, 30001856512 bytes, 58597376 sectors
3.创建 PV
[root@rhel76 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- <59.07g 4.00m
[root@rhel76 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[root@rhel76 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- <59.07g 4.00m
/dev/sdb1 lvm2 --- <20.00g <20.00g
4.扩展逻辑卷
[root@rhel76 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
rhel 1 3 0 wz--n- <59.07g 4.00m
[root@rhel76 ~]# vgextend rhel /dev/sdb1
[root@rhel76 ~]# vgextend rhel /dev/sdb1
Volume group "rhel" successfully extended
[root@rhel76 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
rhel 2 3 0 wz--n- 79.06g 20.00g
[root@rhel76 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
jem_vg 1 0 0 wz--n- <20.00g <20.00g
rhel 1 3 0 wz--n- <59.07g 4.00m
[root@rhel76 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/rhel/root
LV Name root
VG Name rhel
LV UUID fB06rl-92CE-trM6-e2tM-pP4o-6SKt-p03lGC
LV Write Access read/write
LV Creation host, time rhel76, 2021-06-26 22:04:57 +0000
LV Status available
# open 1
LV Size <29.26 GiB
Current LE 7490
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
[root@rhel76 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root rhel -wi-ao---- <29.26g
swap rhel -wi-ao---- 1.86g
u01 rhel -wi-ao---- 27.94g
[root@rhel76 ~]# lvextend -L +18G /dev/rhel/root
Size of logical volume rhel/root changed from <29.26 GiB (7490 extents) to <47.26 GiB (12098 extents).
Logical volume rhel/root successfully resized.
使用以下命令刷新lv
[root@rhel76 ~]# xfs_growfs /dev/rhel/root
meta-data=/dev/mapper/rhel-root isize=512 agcount=4, agsize=1917440 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=7669760, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=3745, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 7669760 to 12388352
5.再次确认分区大小
[root@rhel76 ~]# df -TH
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/rhel-root xfs 51G 4.4G 47G 9% /
devtmpfs devtmpfs 2.1G 0 2.1G 0% /dev
tmpfs tmpfs 2.1G 0 2.1G 0% /dev/shm
tmpfs tmpfs 2.1G 14M 2.1G 1% /run
tmpfs tmpfs 2.1G 0 2.1G 0% /sys/fs/cgroup
/dev/sda1 xfs 996M 172M 825M 18% /boot
/dev/mapper/rhel-u01 xfs 30G 34M 30G 1% /u01
tmpfs tmpfs 413M 4.1k 413M 1% /run/user/42
tmpfs tmpfs 413M 54k 413M 1% /run/user/0
很明显，/ 分区由原来的30G扩展到了51G
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