lvm自动扩容到固定分区脚本

亦凉 2022-01-10 15:15 327阅读 0赞

**任务**：需要在nagios中监控aws的一些虚拟主机，检测/data分区容量，一旦该分区容量低于某个值，就执行脚本利用aws命令指令去创建卷，挂载卷到/data分区容量不足的主机上，然后在主机上利用lvm自动扩充/data分区的容量。利用aws命令去创建挂载磁盘的脚本由lead编写，我需要写lvm自动扩充的脚本。

**脚本如下**：

\#!/bin/bash  
exec &>/tmp/.lvm \#将所有正确和错误输出记录到/tmp/.lvm,追加记录就用>>/tmp/.lvm

\#decteing /data partion \#检测有没有data分区存在，如果没有就退出脚本  
df|grep -i '/data' || \{  
echo "no found /data"  
exit 1  
\}

\#Judge /data is which vulume \#取出/data分区对应的vg名称赋给VG变量，如果VG变量为空值就退出脚本  
VG=`df -h|grep -i "/data"|cut -d/ -f 4|cut -d\- -f 1`  
\[ ! -n "$VG" \] && \{  
echo 'no found $VG'  
exit 1  
\}

\#decte new whick disk \#检测新增加磁盘文件名是什么，如果新增了多块，则取最后一块  
PRESENT=`sudo lsblk --all | grep disk | grep nvme | awk '{print $1}'`  
do  
NUM=`fdisk -l | grep $i | wc -l`  
DISK\_PVS="`pvs|grep $i`"  
REQ=$?  
if \[ "$NUM" == 1 -a "$REQ" == "1" \]  
then  
echo "$i is new add disk" >> $\{LOG\_FILE\}  
DEV=/dev/$i  
fi  
done

\[ ! -n "$DEV" \] && \{ \#判断dev变量是否为空  
echo 'no found $DEV to extended' |tee -a $\{LOG\_FILE\}  
exit 1  
\}

\#create new pv \#创建pv操作  
sudo pvcreate $\{DEV\} || \{  
echo "pv create faild"  
exit 1  
\}

\#extend vg size \#扩充VG大小  
sudo vgextend $\{VG\} $\{DEV\} || \{  
echo "vg extend failed"  
exit 1  
\}

\#lvextend /data partion \#lv卷扩充操作  
LV=`df|grep -i '/data'|awk '{print $1}'` \#截取/data分区lvm卷名  
\[ ! -n "$LV" \] && \{  
echo 'no found $LV'  
exit 1  
\}

sudo lvextend -l +100%FREE $\{LV\} || \{ \#扩充/data分区lvm卷  
echo "lv extend failed"  
exit 1  
\}

\#extend filesystem \#扩充文件系统大小，如果是ext4分区，执行resize2fs命令.....  
FILESYSTEM=`mount | grep "${LV}"|awk '{print $5}'`  
case $FILESYSTEM in  
ext4)  
sudo resize2fs $\{LV\}  
;;  
xfs)  
sudo xfs\_growfs $\{LV\}  
;;  
\*)  
echo "unkown filesystem"  
;;  
esac

**在虚拟机中测试如下：**  
1./data分区大小：/dev/mapper/test-test--lv 40G 48M 38G 1% /data  
2.添加一块磁盘并执行脚本：/dev/mapper/test-test--lv 69G 52M 66G 1% /data  
3.日志记录如下：  
\[root@localhost shell\]\# cat /tmp/.lvm  
/dev/mapper/test-test--lv 41153760 49080 39375144 1% /data  
nvme0n3 is new add disk  
Physical volume "/dev/nvme0n3" successfully created  
Volume group "test" successfully extended  
Size of logical volume test/test-lv changed from 49.98 GiB (12796 extents) to 69.98 GiB (17916 extents).  
Logical volume test-lv successfully resized.  
resize2fs 1.42.9 (28-Dec-2013)  
Filesystem at /dev/mapper/test-test--lv is mounted on /data; on-line resizing required  
old\_desc\_blocks = 5, new\_desc\_blocks = 9  
The filesystem on /dev/mapper/test-test--lv is now 18345984 blocks long.

在nagios中测试，只要检测到/data分区容量不足某个阀值，就触发一系列脚本完成空间自动扩容  
![lvm自动扩容到固定分区脚本][lvm]

这是在lead那里测试的，所以没有记录，因为要反复测试多次，添加不同的aws磁盘类型，扩充lvm后需要将空间缩小，磁盘移除等操作，这样才方便测试，可通过如下脚本将刚添加的磁盘移除：  
\#!/bin/bash  
if \[ $\# -ne 2 \];then  
echo "Usage: $0 reduce2size reducesize ,i.e: 40G 500G"  
exit 10  
fi  
LV=`df|grep -i '/data'|awk '{print $1}'`  
VG=`df -h|grep -i "/data"|cut -d/ -f 4|cut -d\- -f 1`  
sudo umount /data/ || exit 1  
sudo e2fsck -f $\{LV\} || exit 3  
sudo resize2fs $\{LV\} $1 || exit 2  
sudo e2fsck -f $\{LV\} || exit 3  
sudo lvreduce -L -$2 $\{LV\} || exit 4  
\#VGREDUCE=`sudo pvs|grep -i ${VG}|grep nvme|awk 'NR==1{print $1}'`  
VGREDUCE='/dev/nvme1n1' \#这里写要移除的磁盘文件名  
sudo vgdisplay -v | grep $\{VGREDUCE\} || exit 5  
sudo vgreduce $\{VG\} $\{VGREDUCE\} || exit 6  
sudo pvs|grep $\{VGREDUCE\} || exit 7  
sudo pvremove $\{VGREDUCE\} || exit 8  
sudo mount $\{LV\} /data || exit 9

注：这是在ext4文件系统下做的测试，xfs文件系统好像不能缩小空间，只能增大

转载于:https://blog.51cto.com/pkimin3/2399583

[lvm]: https://s1.51cto.com/images/blog/201905/24/3a91452f1d21afdd221c4b96e464346e.png?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_90,type_ZmFuZ3poZW5naGVpdGk=