概要
无论虚拟机还是企业维护的正式服务器，安装应用过多过，必定面临磁盘不够用的情况，特别个人实验使用的虚拟机，应该对磁盘使用做好规划。文件系统使用的基本规划
挂载目录 | 系统类型 | 作用 | 是否扩展 |
/ | 本地系统 | 存放OS文件和常用包 | 否 |
/opt | lvm | 存放应用软件和数据 | 是 |
扩展过程
1查看文件系统使用情况
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 18G 17G 1G 99% /
devtmpfs 471M 0 471M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 8.4M 478M 2% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/sda1 297M 147M 151M 50% /boot
tmpfs 98M 8.0K 98M 1% /run/user/42
tmpfs 98M 0 98M 0% /run/user/0
2用虚拟机增加磁盘
3 查看增加后的磁盘
[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 17.7G 0 part /
sdb 8:16 0 5G 0 disk
sr0 11:0 1 1024M 0 rom
4 对新增磁盘分区
[root@localhost ~]# 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 0x53ba8de0.
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):
First sector (2048-10485759, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-10485759, default 10485759):
Using default value 10485759
Partition 1 of type Linux and of size 5 GiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
5 写分区信息到内核
[root@localhost ~]# partprobe
6 验证分区已添加
[root@localhost ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 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: 0x000afea4
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 616447 307200 83 Linux
/dev/sda2 616448 4810751 2097152 82 Linux swap / Solaris
/dev/sda3 4810752 41943039 18566144 83 Linux
Disk /dev/sdb: 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
Disk label type: dos
Disk identifier: 0x53ba8de0
Device Boot Start End Blocks Id System
/dev/sdb1 2048 10485759 5241856 83 Linux
lvm原理图如下
具体原理可参考
https://blog.csdn.net/beginerToBetter/article/details/129367828
7 按图中所示步骤创建lvm
[root@localhost ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[root@localhost ~]# pvdisplay
"/dev/sdb1" is a new physical volume of "<5.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size <5.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 7S3jJR-jJuf-2bJA-ZDJP-tEz1-QjGm-CHeOVG
[root@localhost ~]# vgcreate vg1 /dev/sdb1
Volume group "vg1" successfully created
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg1 1 0 0 wz--n- <5.00g <5.00g
[root@localhost ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg1
PV Size <5.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 1279
Free PE 1279
Allocated PE 0
PV UUID 7S3jJR-jJuf-2bJA-ZDJP-tEz1-QjGm-CHeOVG
[root@localhost ~]# lvcreate -L 2G -n lv_app vg1
Logical volume "lv_app" created.
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_app vg1 -wi-a----- 2.00g
[root@localhost ~]# mkfs.xfs /dev/vg1/lv_app
meta-data=/dev/vg1/lv_app isize=512 agcount=4, agsize=131072 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=524288, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, versinotallow=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
8 挂载磁盘到对那个lvm
[root@localhost ~]# mount /dev/vg1/lv_app /opt/
挂载原来如下图
9 扩容lvm
[root@localhost ~]# lvextend -L +100M /dev/mapper/vg1-lv_app -r
Size of logical volume vg1/lv_app changed from 2.30 GiB (589 extents) to <2.40 GiB (614 extents).
Logical volume vg1/lv_app successfully resized.
10 挂载永久生效
[root@localhost ~]# df -T
/dev/mapper/vg1-lv_app xfs 2086912 32992 2053920 2% /opt
[root@localhost ~]# vi /etc/fstab
/dev/mapper/vg1-lv_app /opt xfs defaults 0 0
#最终重启生效
[root@localhost ~]# reboot
