Linux系统在线扩容（根目录）磁盘空间

fdisk -l

echo "- - -" > /sys/class/scsi_host/host0/scan
echo "- - -" > /sys/class/scsi_host/host1/scan
echo "- - -" > /sys/class/scsi_host/host2/scan

cat usr/local/src/test.sh


#!/usr/bin/bash


scsisum=`ll sys/class/scsi_host/host*|wc -l`


for ((i=0;i<${scsisum};i++))
do
    echo "- - -" > sys/class/scsi_host/host${i}/scan
done


#echo "- - -" > /sys/class/scsi_host/host0/scan 这三个值代表通道，SCSI目标ID和LUN。破折号充当通配符，意思是“重新扫描一切”

$ fdisk /dev/sdc
# fdisk的交互模式，依次输入


n  --创建新分区
p  --创建主分区
<回车>  --默认分区编号
<回车>  --默认起始扇区位置。
<回车>  --默认结束扇区位置。
t  --设置分区类型
8e  类型为LVM
w  --写入分区表

fdisk -l /dev/sdc

[root@compute2 ~]# vgdisplay -v
--- Volume group ---
VG Name centos       # 卷分组名，后面会用到这个名字
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 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 12.00 GiB
PE Size 4.00 MiB
Total PE 3073
Alloc PE / Size 3072 / 12.00 GiB
Free PE / Size 1 / 4.00 MiB  # 这一项表示目前该系统上还存在4.00G的空闲空间,可以增加到其它分区上使用
VG UUID gjNdOE-1caE-oOKW-CzOU-3JTz-NUFY-f5R5my

[root@compute2 ~]# pvdisplay /dev/sdc3
"/dev/sdc3" is a new physical volume of "<10.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdc3
VG Name
PV Size <10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID w7wpuN-2kvs-v8Zp-3y6V-ptpC-QvFq-BAWQ9O

[root@compute2 ~]# vgextend centos /dev/sdc3
  Volume group "centos" successfully extended

[root@compute2 ~]# df -h|grep '/$'
/dev/mapper/centos-root 10G 6.7G 3.4G 67% /

[root@compute2 ~]# lvextend -L +5G /dev/mapper/centos-root
Size of logical volume centos/root changed from 10.00 GiB (2560 extents) to 15.00 GiB (3840 extents).
Logical volume centos/root successfully resized.

# 使用 resize2fs或xfs_growfs 对挂载目录在线扩容
# resize2fs 针对文件系统ext2 ext3 ext4
# xfs_growfs 针对文件系统xfs
[root@compute2 ~]# xfs_growfs /dev/mapper/centos-root 
meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=655360 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=2621440, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 2621440 to 3932160

df -h