97. k8s持久化存储
文章目录
- 8. 持久化存储
- 8.1 emptyDir类型：
- 8.2 HostPath类型：
- 8.3 NFS共享存储
- 8.4 pvc（persistentVolumeReclaimPolicy）
- 8.4.1 安装nfs服务端(10.0.0.11)
- 8.4.2 node节点安装nfs客户端
- 8.4.3 创建pv和pvc
- 8.4.4 创建mysql-rc,pod模板里使用volume
- 8.4.5 验证持久化
- 8.5 分布式存储glusterfs
- 8.5.1 glusterfs介绍
- 8.5.2 安装glusterfs
- 8.5.3 添加存储资源池
- 8.5.4 glusterfs卷管理
- 8.5.5 分布式复制卷扩容
- 8.6 k8s 对接glusterfs存储
- 8.6.1 创建endpoint
- 8.6.2 创建service
- 8.7 k8s 映射
- 8.8 创建gluster类型pv（全称“持久化卷”）
- 8.9 创建pvc【局部资源】
8. 持久化存储
痛点：没有做持久化存储的时候，当我们清理容器之后，再次启动pod之后，用户的数据就会丢失，这会严重影响到公司的利益与客户的体验；为了解决这个问题，请看以下几种方案：
8.1 emptyDir类型：
1. 前期准备工作：登录我们的web网站，创建若干条数据；然后进入容器的数据库中查询
2. 配置持久化存储
1.修改yml文件
[root@k8s-master tomcat_demo]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: tomcat
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
volumes: #表示对持久化存储目录做持久化
- name: mysql #名称一一对应
emptyDir: {} #持久化类型
containers:
- name: mysql
image: 10.0.0.11:5000/mysql:5.7
volumeMounts: #挂载
- name: mysql #名称
mountPath: /var/lib/mysql #配置持久化目录
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: '123456'
2.创建pod
[root@k8s-master tomcat_demo]# kubectl delete -f .
[root@k8s-master tomcat_demo]# kubectl create -f .
[root@k8s-master tomcat_demo]# kubectl get all -n tomcat -o wide
NAME DESIRED CURRENT READY AGE CONTAINER(S) IMAGE(S) SELECTOR
rc/mysql 1 1 1 10s mysql 10.0.0.11:5000/mysql:5.7 app=mysql
rc/myweb 2 2 2 10s myweb 10.0.0.11:5000/tomcat-app:v2 app=myweb
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
svc/mysql 10.254.70.69 <none> 3306/TCP 10s app=mysql
svc/myweb 10.254.41.20 <nodes> 8080:30008/TCP 10s app=myweb
NAME READY STATUS RESTARTS AGE IP NODE
po/mysql-sxfqp 1/1 Running 0 10s 172.18.81.4 10.0.0.12
po/myweb-0c0hg 1/1 Running 0 10s 172.18.81.2 10.0.0.12
po/myweb-zzfd8 1/1 Running 0 10s 172.18.7.6 10.0.0.13
3.再次登录网站添加数据----》node1节点清理容器-----》登录web检查
数据的存放位置
[root@k8s-node-1 ~]# cd /var/lib/kubelet/pods/a5301810-1c0b-11ea-8a15-000c29d8ae3b/volumes/kubernetes.io~empty-dir/mysql
4.测试删除pod
[root@k8s-master tomcat_demo]# kubectl delete pod -n tomcat mysql-sxfqp
发现痛点；当我们的Pod发生故障时，启动新pod之后数据也会跟着丢失；
为了解决这个问题，请看下边方案：
8.2 HostPath类型：
持久化到宿主机目录
修改mysql-rc.yml文件
[root@k8s-master tomcat_demo]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: tomcat
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
nodeName: 10.0.0.13
volumes:
- name: mysql
hostPath: #类型
path: /data/mysql #持久化路径
containers:
- name: mysql
image: 10.0.0.11:5000/mysql:5.7
volumeMounts:
- name: mysql
mountPath: /var/lib/mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: '123456'
[root@k8s-master tomcat_demo]# kubectl create -f .
8.3 NFS共享存储
0.修改文件
volumes:
- name: mysql
nfs:
path: /data/wp_mysql
server: 10.0.0.11
1.所有节点安装nfs-utils
yum install nfs-utils -y
mkdir /data
2.nfs服务端配置共享目录：
[root@k8s-master ~]# cat /etc/exports
/data 10.0.0.0/24(rw,async,no_root_squash,no_all_squash)
systemctl start rpcbind nfs-server
3.wordpress项目数据库持久化：
1.配置mysql-rc
[root@k8s-master wordpress]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: wordpress
name: mysql-wp
spec:
replicas: 1
selector:
app: mysql-wp
template:
metadata:
labels:
app: mysql-wp
spec:
volumes:
- name: mysql-wp
nfs:
path: /data/blogsql-db
server: 10.0.0.11
containers:
- name: mysql
image: 10.0.0.11:5000/mysql:5.7
volumeMounts:
- name: mysql-wp
mountPath: /var/lib/mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: 'somewordpress'
- name: MYSQL_DATABASE
value: 'wordpress'
- name: MYSQL_USER
value: 'wordpress'
- name: MYSQL_PASSWORD
value: 'wordpress'
2.配置wordpress-rc
[root@k8s-master wordpress]# cat wordpress-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: wordpress
name: wordpress
spec:
replicas: 2
selector:
app: wordpress
template:
metadata:
labels:
app: wordpress
spec:
volumes:
- name: wordpress
nfs:
path: /data/wordpress-db
server: 10.0.0.11 #apiserver的ip地址
containers:
- name: wordpress
image: 10.0.0.11:5000/wordpress:latest
volumeMounts:
- name: wordpress
mountPath: /var/www/html
ports:
- containerPort: 80
env:
- name: WORDPRESS_DB_HOST
value: 'mysql-wp'
- name: WORDPRESS_DB_USER
value: 'wordpress'
- name: WORDPRESS_DB_PASSWORD
value: 'wordpress'
3.创建对应的目录
mkdir -p /data/blogsql-db
mkdir -p /data/wordpress-db
4.测试数据是否持久化
kubectl delete pod --all -n wordpress
登录web界面测试---》测试数据是否存在
[root@k8s-node-1 ~]# df -Th |grep -i nfs
10.0.0.11:/data/blogsql-db nfs4 48G 3.9G 45G 8% /var/lib/kubelet/pods/a9768011-1c80-11ea-a2dc-000c29d8ae3b/volumes/kubernetes.io~nfs/mysql-wp
10.0.0.11:/data/wordpress-db nfs4 48G 3.9G 45G 8% /var/lib/kubelet/pods/a98fa0ab-1c80-11ea-a2dc-000c29d8ae3b/volumes/kubernetes.io~nfs/wordpress
结果：数据得到了持久化
8.4 pvc（persistentVolumeReclaimPolicy）
pv: persistent volume 全局资源,k8s集群
pvc: persistent volume claim, 局部资源属于某一个namespace
8.4.1 安装nfs服务端(10.0.0.11)
yum install nfs-utils.x86_64 -y
mkdir /data
vim /etc/exports
/data 10.0.0.0/24(rw,async,no_root_squash,no_all_squash)
systemctl start rpcbind
systemctl start nfs
8.4.2 node节点安装nfs客户端
yum install nfs-utils.x86_64 -y
showmount -e 10.0.0.11
8.4.3 创建pv和pvc
上传yaml配置文件,创建pv和pvc
8.4.4 创建mysql-rc,pod模板里使用volume
volumes:
- name: mysql
persistentVolumeClaim:
claimName: tomcat-mysql
8.4.5 验证持久化
验证方法1:删除mysql的pod,数据库不丢
kubectl delete pod mysql-gt054
验证方法2:查看nfs服务端,是否有mysql的数据文件
8.5 分布式存储glusterfs
8.5.1 glusterfs介绍
Glusterfs是一个开源分布式文件系统，具有强大的横向扩展能力，可支持数PB存储容量和数千客户端，通过网络互联成一个并行的网络文件系统。具有可扩展性、高性能、高可用性等特点。
8.5.2 安装glusterfs
所有节点安装glusterfs：
yum install centos-release-gluster -y
yum install install glusterfs-server -y
systemctl start glusterd.service
systemctl enable glusterd.service
#为gluster集群增加存储单元brick
mkdir -p /gfs/test1
mkdir -p /gfs/test2
mkdir -p /gfs/test3
各个节点增加3块为10G硬盘【3个节点都要操作】
echo '- - -' >/sys/class/scsi_host/host0/scan
echo '- - -' >/sys/class/scsi_host/host1/scan
echo '- - -' >/sys/class/scsi_host/host2/scan
mkfs.xfs /dev/sdb
mkfs.xfs /dev/sdc
mkfs.xfs /dev/sdd
mount /dev/sdb /gfs/test1
mount /dev/sdc /gfs/test2
mount /dev/sdd /gfs/test3
8.5.3 添加存储资源池
master节点：
gluster pool list
[root@k8s-master ~]# gluster peer probe k8s-node-1
[root@k8s-master ~]# gluster peer probe k8s-node-2
[root@k8s-master ~]# gluster pool list
UUID Hostname State
faf41469-794a-4460-be0e-65d9fb773be3 k8s-node-1 Connected
a1707123-944a-4395-89ac-0870b640751a k8s-node-2 Connected
08f4b5cc-6a5d-4213-b107-f2c4dd4a59d2 localhost Connected
8.5.4 glusterfs卷管理
1.任何节点都可以创建分布式卷
[root@k8s-master ~]# gluster volume create cheng k8s-master:/gfs/test1 k8s-node-1:/gfs/test1 k8s-node-2:/gfs/test1 force
volume create: cheng: success: please start the volume to access data
2.启动卷并查看卷信息
[root@k8s-master ~]# gluster volume info cheng
Volume Name: cheng
Type: Distribute 分布式卷
Volume ID: 5c17c614-c90d-4c70-b14f-62a8c5903162
Status: Created
Snapshot Count: 0
Number of Bricks: 3
Transport-type: tcp
Bricks:
Brick1: k8s-master:/gfs/test1
Brick2: k8s-node-1:/gfs/test1
Brick3: k8s-node-2:/gfs/test1
Options Reconfigured:
transport.address-family: inet
storage.fips-mode-rchecksum: on
nfs.disable: on
gluster volume start cheng
gluster volume info cheng
3.挂载并测试
mount -t glusterfs 127.0.0.1:/cheng /mnt/
df -h 查看挂载信息
cp /data/wordpress-db/*.php /mnt/
痛点：
每个节点分布了一些数据；痛点是如果又一个盘故障了，会导致数据丢失
4. 增加存储单元【分布式复制卷】
[root@k8s-master ~]# gluster volume add-brick cheng replica 2 k8s-master:/gfs/test2 k8s-node-1:/gfs/test2 k8s-node-2:/gfs/test2 force
- replica 副本数
[root@k8s-master ~]# gluster volume info cheng
Volume Name: cheng
Type: Distributed-Replicate #分布式复制卷
Volume ID: 5c17c614-c90d-4c70-b14f-62a8c5903162
Status: Started
Snapshot Count: 0
Number of Bricks: 3 x 2 = 6
Transport-type: tcp
Bricks:
Brick1: k8s-master:/gfs/test1
Brick2: k8s-master:/gfs/test2
Brick3: k8s-node-1:/gfs/test1
Brick4: k8s-node-1:/gfs/test2
Brick5: k8s-node-2:/gfs/test1
Brick6: k8s-node-2:/gfs/test2
Options Reconfigured:
performance.client-io-threads: off
transport.address-family: inet
storage.fips-mode-rchecksum: on
nfs.disable: on
===============================================================
#创建分布式复制卷
gluster volume create qiangge replica 2 k8s-master:/gfs/test1 k8s-node-1:/gfs/test1 k8s-master:/gfs/test2 k8s-node-1:/gfs/test2 force
#启动卷
gluster volume start qiangge
#查看卷
gluster volume info qiangge
#挂载卷
mount -t glusterfs 10.0.0.11:/qiangge /mnt
8.5.5 分布式复制卷扩容
1.扩容前查看容量：
[root@k8s-master ~]# df -h
/dev/sdb 10G 33M 10G 1% /gfs/test1
/dev/sdc 10G 33M 10G 1% /gfs/test2
/dev/sdd 10G 33M 10G 1% /gfs/test3
127.0.0.1:/cheng 30G 404M 30G 2% /mnt
2.扩容命令：
[root@k8s-master ~]# gluster volume add-brick cheng k8s-master:/gfs/test3 k8s-node-1:/gfs/test3 force
3.扩容后查看容量:
[root@k8s-master ~]# df -h
/dev/sdb 10G 33M 10G 1% /gfs/test1
/dev/sdc 10G 33M 10G 1% /gfs/test2
/dev/sdd 10G 33M 10G 1% /gfs/test3
127.0.0.1:/cheng 40G 539M 40G 2% /mnt
[root@k8s-master ~]# gluster volume info cheng
Volume Name: cheng
Type: Distributed-Replicate
Volume ID: 5c17c614-c90d-4c70-b14f-62a8c5903162
Status: Started
Snapshot Count: 0
Number of Bricks: 4 x 2 = 8
Transport-type: tcp
Bricks:
Brick1: k8s-master:/gfs/test1
Brick2: k8s-master:/gfs/test2
Brick3: k8s-node-1:/gfs/test1
Brick4: k8s-node-1:/gfs/test2
Brick5: k8s-node-2:/gfs/test1
Brick6: k8s-node-2:/gfs/test2
Brick7: k8s-master:/gfs/test3
Brick8: k8s-node-1:/gfs/test3
Options Reconfigured:
performance.client-io-threads: off
transport.address-family: inet
storage.fips-mode-rchecksum: on
nfs.disable: on
4.让数据均衡分布【建议在晚上做，白天做的话会大量消耗磁盘的IO】
[root@k8s-master ~]# gluster volume rebalance cheng start
这时候分布式卷的内容一致，同时也不需要再次挂载
8.6 k8s 对接glusterfs存储
8.6.1 创建endpoint
vi glusterfs-ep.yaml
iapiVersion: v1
kind: Endpoints
metadata:
name: glusterfs
namespace: tomcat
subsets:
- addresses:
- ip: 10.0.0.11
- ip: 10.0.0.12
- ip: 10.0.0.13
ports:
- port: 49152
protocol: TCP
8.6.2 创建service
vi glusterfs-svc.yaml
iapiVersion: v1
kind: Service
metadata:
name: glusterfs
namespace: tomcat
spec:
ports:
- port: 49152
protocol: TCP
targetPort: 49152
sessionAffinity: None
type: ClusterIP
[root@k8s-master glusterfs]# kubectl describe svc glusterfs -n tomcat
Name: glusterfs
Namespace: tomcat
Labels: <none>
Selector: <none>
Type: ClusterIP
IP: 10.254.150.156
Port: <unset> 49152/TCP
Endpoints: 10.0.0.11:49152,10.0.0.12:49152,10.0.0.13:49152
Session Affinity: None
No events.
===================================================================================
tomcat对接glusterfs
===================================================================================
[root@k8s-master tomcat_demo]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: tomcat
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
nodeName: 10.0.0.13
volumes:
- name: mysql
glusterfs:
path: cheng
endpoints: glusterfs
containers:
- name: mysql
image: 10.0.0.11:5000/mysql:5.7
volumeMounts:
- name: mysql
mountPath: /var/lib/mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: '123456'
[root@k8s-master tomcat_demo]# kubectl get all -n tomcat -o wide
NAME DESIRED CURRENT READY AGE CONTAINER(S) IMAGE(S) SELECTOR
rc/mysql 1 1 1 3m mysql 10.0.0.11:5000/mysql:5.7 app=mysql
rc/myweb 2 2 2 3m myweb 10.0.0.11:5000/tomcat-app:v2 app=myweb
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
svc/glusterfs 10.254.150.156 <none> 49152/TCP 7m <none>
svc/mysql 10.254.219.210 <none> 3306/TCP 3m app=mysql
svc/myweb 10.254.247.11 <nodes> 8080:30008/TCP 3m app=myweb
NAME READY STATUS RESTARTS AGE IP NODE
po/mysql-12xg6 1/1 Running 0 27s 172.18.7.6 10.0.0.13
po/myweb-ffg16 1/1 Running 0 27s 172.18.81.7 10.0.0.12
po/myweb-w1gqg 1/1 Running 0 27s 172.18.81.6 10.0.0.12
所有数据存在glusterfs存储中
8.7 k8s 映射
wordpress项目实战：独立数据库服务至宿主机--》k8s 映射
把外部的服务，通过创建service和endpoint，把它映射到k8s内部来使用
提前在宿主机安装mysql服务
[root@k8s-node-2 ~]# yum install mariadb-server mariadb -y
[root@k8s-node-2 ~]# systemctl start mariadb
[root@k8s-node-2 ~]# mysql_secure_installation
0.创建wordpress库，并授权
MariaDB [(none)]> grant all on wordpress.* to wordpress@'%' identified by 'wordpress';
MariaDB [(none)]> create database wordpress;
1.编写mysql-ep配置文件
[root@k8s-master wordpress]# cat mysql-ep.yaml
apiVersion: v1
kind: Endpoints
metadata:
name: mysql-wp
namespace: wordpress
subsets:
- addresses:
- ip: 10.0.0.13
ports:
- port: 3306
protocol: TCP
2.配置mysql-svc文件
[root@k8s-master wordpress]# cat mysql-svc.yml
apiVersion: v1
kind: Service
metadata:
namespace: wordpress
name: mysql-wp
spec:
ports:
- port: 3306
targetPort: 3306 #这儿注意，不能声明标签选择器
3.编写wordpress-rc配置文件
[root@k8s-master wordpress]# cat wordpress-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: wordpress
name: wordpress
spec:
replicas: 2
selector:
app: wordpress
template:
metadata:
labels:
app: wordpress
spec:
volumes:
- name: wordpress
nfs:
path: /data/wordpress-db
server: 10.0.0.11
containers:
- name: wordpress
image: 10.0.0.11:5000/wordpress:latest
volumeMounts:
- name: wordpress
mountPath: /var/www/html
ports:
- containerPort: 80
env:
- name: WORDPRESS_DB_HOST
value: 'mysql-wp'
- name: WORDPRESS_DB_USER
value: 'wordpress'
- name: WORDPRESS_DB_PASSWORD
value: 'wordpress'
4.编写wordpress-svc配置文件
[root@k8s-master wordpress]# cat wordpress-svc.yml
apiVersion: v1
kind: Service
metadata:
namespace: wordpress
name: wordpress
spec:
type: NodePort
ports:
- port: 80
nodePort: 30009
selector:
app: wordpress
检查有没有连接到后端的数据库
[root@k8s-master wordpress]# kubectl describe svc -n wordpress mysql-wp
Name: mysql-wp
Namespace: wordpress
Labels: <none>
Selector: <none>
Type: ClusterIP
IP: 10.254.97.196
Port: <unset> 3306/TCP
Endpoints: 10.0.0.13:3306 #表示已连接到10.0.0.13数据库
Session Affinity: None
No events.
注意：
k8s在做映射的时候，不能做标签选择器
8.8 创建gluster类型pv（全称“持久化卷”）
全局资源：所有namespace都能看见的资源 node pv namespace
局部资源：只属于某一个具体namespace下的资源， 比如：pod、rc、deploy、rs、svc、daemonset
pvc就是pv的分配，pvc是来筛选pv的（根据标签来选）
我们需要什么就创建pvc即可
1.编写mysql_pv配置文件
[root@k8s-master ~]# mkdir /data/pv{1,2}
[root@k8s-master pv_pvc]# cat mysql_pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv1
labels:
type: nfs #pv的标签
spec:
capacity: #提供的存储能力10G，作为筛选pv的标识
storage: 10Gi
accessModes: #访问模式
- ReadWriteMany #允许多个pod同时挂载读写
persistentVolumeReclaimPolicy: Recycle #pv的回收策略
nfs: #后端存储
path: "/data/pv1"
server: 10.0.0.11
readOnly: false
创建Pv
[root@k8s-master pv_pvc]# kubectl create -f mysql_pv.yaml
persistentvolume "pv1" created
查看pv【全局资源】
[root@k8s-master pv_pvc]# kubectl get pv
NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM REASON AGE
pv1 10Gi RWX Recycle Available 23s
==============================================================
2.编写pv2配置文件
[root@k8s-master pv_pvc]# cat mysql_pv2.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv2
labels:
type: nfs #pv的标签
spec:
capacity: #提供的存储能力10G，作为筛选pv的标签
storage: 30Gi
accessModes:
- ReadWriteMany
persistentVolumeReclaimPolicy: Recycle #pv的回收策略
nfs: #后端存储
path: "/data/pv2"
server: 10.0.0.11
readOnly: false
创建pv2
[root@k8s-master pv_pvc]# kubectl create -f mysql_pv2.yaml
persistentvolume "pv2" created
查看pv
[root@k8s-master pv_pvc]# kubectl get pv
NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM REASON AGE
pv1 10Gi RWX Recycle Available 2m
pv2 30Gi RWX Recycle Available 4s
8.9 创建pvc【局部资源】
声明namespace
1.创建mysql_pvc
[root@k8s-master pv_pvc]# cat mysql_pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: pvc1 #Pvc名称
namespace: tomcat #给tomcat做持久化
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 30Gi
创建pvc
[root@k8s-master pv_pvc]# kubectl create -f mysql_pvc.yaml
persistentvolumeclaim "pvc1" created
查看pvc
[root@k8s-master pv_pvc]# kubectl get pvc -n tomcat
NAME STATUS VOLUME CAPACITY ACCESSMODES AGE
pvc1 Bound pv2 30Gi RWX 19s
2：在tomcat pod中使用pvc
[root@k8s-master tomcat_demo]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
namespace: tomcat
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
nodeName: 10.0.0.13
volumes:
- name: mysql
persistentVolumeClaim: #pvc类型
claimName: pvc1 #pvc的名字
containers:
- name: mysql
image: 10.0.0.11:5000/mysql:5.7
volumeMounts:
- name: mysql
mountPath: /var/lib/mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: '123456'
kubectl create -f .
3.查看数据
[root@k8s-master tomcat_demo]# ll /data/pv2/
total 237668
-rw-r----- 1 polkitd input 56 Dec 12 19:26 auto.cnf
drwxr-x--- 2 polkitd input 58 Dec 12 19:27 HPE_APP
-rw-r----- 1 polkitd input 1329 Dec 12 19:26 ib_buffer_pool
-rw-r----- 1 polkitd input 79691776 Dec 12 19:27 ibdata1
-rw-r----- 1 polkitd input 50331648 Dec 12 19:27 ib_logfile0
-rw-r----- 1 polkitd input 50331648 Dec 12 19:26 ib_logfile1
-rw-r----- 1 polkitd input 12582912 Dec 12 19:26 ibtmp1
drwxr-x--- 2 polkitd input 4096 Dec 12 19:26 mysql
drwxr-x--- 2 polkitd input 8192 Dec 12 19:26 performance_schema
drwxr-x--- 2 polkitd input 8192 Dec 12 19:26 sys
4. 测试删除所有pod（删除之前登录web写入数据，主要目的测试数据是否持久化在pv）
[root@k8s-master tomcat_demo]# kubectl delete pod -n tomcat --all
pod "mysql-778s7" deleted
pod "myweb-4d8fb" deleted
pod "myweb-5rkfp" deleted
5. 验证：
