linux中的nfs、iscsi共享服务

nfs（Net File System），网络文件系统，英文Network File System(NFS)，是由SUN公司研制的UNIX表示层协议(presentation layer protocol)，能使使用者访问网络上别处的文件就像在使用自己的计算机一样。

nfs基本信息

nfs-utils 安装包
nfs-server 服务脚本

/etc/exports 共享配置文件

nfs的安装与启用

在westos_strage 172.25.254.100主机上：

75 dnf install nfs-utils.x86_64 -y   ##安装nfs-utils
   76 systemctl enable --now nfs-server.service   ##开启nfs-server服务
   79 firewall-cmd --permanent --add-service=nfs   ##防火墙中永久添加nfs、rpc-bind、mountd服务
   81 firewall-cmd --permanent --add-service=mountd
   82 firewall-cmd --permanent --add-service=rpc-bind
   83 firewall-cmd --reload   ##重载火墙使设定生效

[root@westos_storage ~]# dnf install nfs-utils.x86_64 -y
Updating Subscription Management repositories.
Unable to read consumer identity
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Last metadata expiration check: 0:02:53 ago on Wed 11 Aug 2021 09:12:09 AM CST.
Package nfs-utils-1:2.3.3-31.el8.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
[root@westos_storage ~]# systemctl enable --now nfs-server.service
Created symlink /etc/systemd/system/multi-user.target.wants/nfs-server.service → /usr/lib/systemd/system/nfs-server.service.
[root@westos_storage ~]# netstat -antlupe | grep 2049
tcp        0      0 0.0.0.0:2049            0.0.0.0:*               LISTEN      0          39364      -
tcp6       0      0 :::2049                 :::*                    LISTEN      0          39375      -
[root@westos_storage ~]# firewall-cmd --permanent --add-service=nfs
success
[root@westos_storage ~]# firewall-cmd --permanent --add-service=mountd
success
[root@westos_storage ~]# firewall-cmd --permanent --add-service=rpc-bind
success
[root@westos_storage ~]# firewall-cmd --reload
success

在westoslinux 172.25.254.200主机上：

showmount -e 172.25.254.100 ##查看nfs服务器上的所有共享资源

[root@westoslinux ~]# showmount -e 172.25.254.100   ##列出服务器的共享资源
Export list for 172.25.254.100:

nfs配置参数

anonuid=1000,anongid=1000           ##指定用户身份
sync                                                   ##更改生成后同步数据到服务器
async                                                 ##时时同步数据到服务器
rw                                                       ##读写
ro                                                        ##只读
no_root_squash                                   ##root用户挂载不转换身份

**共享资源使用方式：mount 172.25.254.100:/westosdir /mnt/
**man 5 exports :可以查看共享策略文件的书写参数和共享书写方式

实验：

（1）、在westos_strage 172.25.254.100主机上：

[root@westos_storage ~]# mkdir /westosdir  ##建立共享目录
[root@westos_storage ~]# ls -ld /westosdir   ##查看目录权限
drwxr-xr-x. 2 root root 6 Aug 11 09:37 /westosdir
[root@westos_storage ~]# chmod 777 /westosdir/  ##在进行参数设置之前，为了不使共享的本地文件系统的权限设定限制我们写入文件，需要将共享目录的权限设置为777
[root@westos_storage ~]# ls -ld /westosdir
drwxrwxrwx. 2 root root 6 Aug 11 09:37 /westosdir
[root@westos_storage ~]# vim /etc/exports   ##修改共享策略文件
//1 /westosdir   *(ro,sync)   ##只读共享，并在数据真实发生改变后才同步数据到nfs共享目录
//
[root@westos_storage ~]# exportfs -rv  ##使共享策略生效
exporting *:/westosdir

在客户端westoslinux 172.25.254.200主机上可以查看到共享：

[root@westoslinux ~]# showmount -e 172.25.254.100
Export list for 172.25.254.100:
/westosdir *

（2）、修改westos_strage 172.25.254.100主机的共享策略文件，对于除200主机以外的只读共享，对200主机读写共享：

[root@westos_storage ~]# touch /westosdir/westosfile{1..3}
[root@westos_storage ~]# vim /etc/exports
//2 /westosdir   172.25.254.200(rw,sync)  或者 1 /westosdir   *(ro,sync) 172.25.254.200(rw,sync)
//
[root@westos_storage ~]# exportfs -rv
exporting 172.25.254.200:/westosdir
exporting *:/westosdir

在客户端westoslinux 172.25.254.200主机上可以在共享目录中新建文件：

[root@westoslinux ~]# mount 172.25.254.100:/westosdir /mnt/
[root@westoslinux ~]# touch /mnt/westosfile4
[root@westoslinux ~]# unmount /mnt/

查询westos_strage 172.25.254.100主机上的共享目录：

[root@westos_storage ~]# ls /westosdir -l
total 0
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile1
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile2
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile3
-rw-r--r--. 1 nobody nobody 0 Aug 11 09:48 westosfile4   ##新建文件成功,当客户端挂载共享到本地目录后，使用到的用户身份是服务器上的nobody

（3）、修改westos_strage 172.25.254.100主机的共享策略文件，对于除200主机以外的只读共享，对200主机读写共享并指定客户端挂载时使用的用户为1000，不是默认的nobody：

[root@westos_storage ~]# vim /etc/exports
//2 /westosdir   172.25.254.200(rw,sync,anonuid=1000,anongid=1000)
//
[root@westos_storage ~]# exportfs -rv
exporting 172.25.254.200:/westosdir
exporting *:/westosdir

在客户端westoslinux 172.25.254.200主机上可以在共享目录中新建文件：

[root@westoslinux ~]# mount 172.25.254.100:/westosdir /mnt/
[root@westoslinux ~]# cd /mnt/
[root@westoslinux mnt]# touch file6
[root@westoslinux mnt]# ls /mnt/
file6  westosfile1  westosfile2  westosfile3  westosfile4
[root@westoslinux mnt]# cd
[root@westoslinux ~]# umount /mnt/

查询westos_strage 172.25.254.100主机上的共享目录：

[root@westos_storage ~]# ls /westosdir -l
total 0
-rw-r--r--. 1 westos westos 0 Aug 11 09:53 file6   ####用户和组设置成功
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile1
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile2
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile3
-rw-r--r--. 1 nobody nobody 0 Aug 11 09:48 westosfile4

（4）、修改westos_strage 172.25.254.100主机的共享策略文件，对于除200主机以外的只读共享，对200主机读写共享并当客户端使用超级用户挂载后沿用自己的root用户身份到服务器中：

[root@westos_storage ~]# vim /etc/exports
//2 /westosdir   172.25.254.200(rw,sync,no_root_squash)
//
[root@westos_storage ~]# exportfs -rv
exporting 172.25.254.200:/westosdir
exporting *:/westosdir

在客户端westoslinux 172.25.254.200主机上可以在共享目录中新建文件：

[root@westoslinux ~]# mount 172.25.254.100:/westosdir /mnt/
[root@westoslinux ~]# cd /mnt
[root@westoslinux mnt]# touch file7

查询westos_strage 172.25.254.100主机上的共享目录：

[root@westos_storage ~]# ls /westosdir -l
total 0
-rw-r--r--. 1 westos westos 0 Aug 11 09:53 file6
-rw-r--r--. 1 root   root   0 Aug 11 09:55 file7   ##设置成功
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile1
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile2
-rw-r--r--. 1 root   root   0 Aug 11 09:44 westosfile3
-rw-r--r--. 1 nobody nobody 0 Aug 11 09:48 westosfile4

nfs+autofs服务客户端共享优化自动挂载

dnf install autofs -y ##在客户端安装自动挂载服务autofs
vim /etc/auto.master ##编辑主挂载策略文件
//
9 /westos /etc/auto.nfs
最终挂载点的上层目录子策略文件
//

vim /etc/auto.nfs
//
nfs -rw 172.25.254.100:/westosdir
最终挂载点的相对路径挂载参数 nfs服务器上共享出来的资源
//
systemctl restart autofs.service ##重启服务

实验：

[root@westoslinux mnt]# vim /etc/auto.master
//
9 /westos       /etc/auto.nfs
//
[root@westoslinux mnt]# vim /etc/auto.nfs
//
nfs -rw  172.25.254.100:/westosdir
//
[root@westoslinux mnt]# systemctl restart autofs.service
[root@westoslinux mnt]# df    ##查询挂载
Filesystem                1K-blocks    Used Available Use% Mounted on
devtmpfs                     403532       0    403532   0% /dev
tmpfs                        419132       0    419132   0% /dev/shm
tmpfs                        419132    6308    412824   2% /run
tmpfs                        419132       0    419132   0% /sys/fs/cgroup
/dev/vda3                  17814528 3342832  14471696  19% /
/dev/vda1                   1038336  173172    865164  17% /boot
tmpfs                         83824    1180     82644   2% /run/user/42
tmpfs                         83824       4     83820   1% /run/user/0
172.25.254.100:/westosdir  17814528 3346688  14467840  19% /mnt
[root@westoslinux mnt]# cd
[root@westoslinux ~]# umount /mnt  ##卸载
[root@westoslinux ~]# cd /westos/
[root@westoslinux westos]# ls
[root@westoslinux westos]# cd nfs
[root@westoslinux nfs]# df
Filesystem                1K-blocks    Used Available Use% Mounted on
devtmpfs                     403532       0    403532   0% /dev
tmpfs                        419132       0    419132   0% /dev/shm
tmpfs                        419132    6308    412824   2% /run
tmpfs                        419132       0    419132   0% /sys/fs/cgroup
/dev/vda3                  17814528 3342832  14471696  19% /
/dev/vda1                   1038336  173172    865164  17% /boot
tmpfs                         83824    1180     82644   2% /run/user/42
tmpfs                         83824       4     83820   1% /run/user/0
172.25.254.100:/westosdir  17814528 3346688  14467840  19% /westos/nfs
[root@westoslinux nfs]# cd
[root@westoslinux ~]# df
Filesystem                1K-blocks    Used Available Use% Mounted on
devtmpfs                     403532       0    403532   0% /dev
tmpfs                        419132       0    419132   0% /dev/shm
tmpfs                        419132    6308    412824   2% /run
tmpfs                        419132       0    419132   0% /sys/fs/cgroup
/dev/vda3                  17814528 3342832  14471696  19% /
/dev/vda1                   1038336  173172    865164  17% /boot
tmpfs                         83824    1180     82644   2% /run/user/42
tmpfs                         83824       4     83820   1% /run/user/0
172.25.254.100:/westosdir  17814528 3346688  14467840  19% /westos/nfs
[root@westoslinux ~]# df   ##过3妙，挂载自动卸载
Filesystem     1K-blocks    Used Available Use% Mounted on
devtmpfs          403532       0    403532   0% /dev
tmpfs             419132       0    419132   0% /dev/shm
tmpfs             419132    6304    412828   2% /run
tmpfs             419132       0    419132   0% /sys/fs/cgroup
/dev/vda3       17814528 3342832  14471696  19% /
/dev/vda1        1038336  173172    865164  17% /boot
tmpfs              83824    1180     82644   2% /run/user/42
tmpfs              83824       4     83820   1% /run/user/0

iscsi设备共享

iscsi直接共享设备的读写权限，其具体共享方式如下：

先给虚拟机westos_strage 172.25.254.100添加一块2G硬盘

(1).在westos_strage 172.25.254.100主机端：

dnf install targetcli -y ##下载共享策略管理软件
systemctl enable --now target ##开启target服务
targetcli ##用此命令编写共享策略

其中：
/backstores/block create westos:storage1 /dev/vdb1
再此软件设备中的别名 /dev/vdb1系统中真实设备

/iscsi create iqn.2021-08.org.westos:storage1
##建立对外的共享名称，iqn的命名方式
##iscsi限定名称
##格式iqn.YYYY-MM.域名反写：别名

/iscsi/iqn.2021-08.org.westos:storage1/tpg1/luns create /backstores/block/westos:storage1
##把共享名称和内部制定设备关联

/iscsi/iqn.2021-08.org.westos:storage1/tpg1/acls create iqn.2021-08.org.westos:westoskey
##为共享设备设定访问key westoskey是加密字符

firewall-cmd --permanent --add-port=3260/tcp
firewall-cmd --reload

具体操作：

[root@westos_storage ~]# fdisk -l  ##查看磁盘的分区情况
Disk /dev/vda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x34fd8722Device     Boot   Start      End  Sectors Size Id Type
/dev/vda1  *       2048  2099199  2097152   1G 83 Linux
/dev/vda2       2099200  6293503  4194304   2G 82 Linux swap / Solaris
/dev/vda3       6293504 41943039 35649536  17G 83 LinuxDisk /dev/vdb: 5 GiB, 5368709120 bytes, 10485760 sectors   ##/dev/vdb硬盘添加成功
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
[root@westos_storage ~]# fdisk /dev/vdb  ##使用交互式分区方式fdisk /dev/vdb在该硬盘上新建一个大小为2G的设备/dev/vdb1Welcome to fdisk (util-linux 2.32.1).
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.
Created a new DOS disklabel with disk identifier 0xd6c941f3.Command (m for help): n
Partition typep   primary (0 primary, 0 extended, 4 free)e   extended (container for logical partitions)
Select (default p): Using default response p.
Partition number (1-4, default 1):
First sector (2048-10485759, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-10485759, default 10485759): +2GCreated a new partition 1 of type 'Linux' and of size 2 GiB.
Partition #1 contains a LVM2_member signature.Do you want to remove the signature? [Y]es/[N]o: YThe signature will be removed by a write command.Command (m for help): p
Disk /dev/vdb: 5 GiB, 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
Disklabel type: dos
Disk identifier: 0xd6c941f3Device     Boot Start     End Sectors Size Id Type
/dev/vdb1        2048 4196351 4194304   2G 83 LinuxFilesystem/RAID signature on partition 1 will be wiped.Command (m for help): wq
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.[root@westos_storage ~]# dnf install targetcli -y  ##下载共享策略管理软件[root@westos_storage ~]# systemctl enable --now target
Created symlink /etc/systemd/system/multi-user.target.wants/target.service → /usr/lib/systemd/system/target.service.
[root@westos_storage ~]#  targetcli
Warning: Could not load preferences file /root/.targetcli/prefs.bin.
targetcli shell version 2.1.51
Copyright 2011-2013 by Datera, Inc and others.
For help on commands, type 'help'./> ls
o- / ............................................................... [...]o- backstores .................................................... [...]| o- block ........................................ [Storage Objects: 0]| o- fileio ....................................... [Storage Objects: 0]  ##蓝色为目录，紫色为目录中的命令| o- pscsi ........................................ [Storage Objects: 0]| o- ramdisk ...................................... [Storage Objects: 0]o- iscsi .................................................. [Targets: 0]o- loopback ............................................... [Targets: 0]
/> /backstores/block create westos:storage1 /dev/vdb1      ####代码上面有详细解释
Created block storage object westos:storage1 using /dev/vdb1.
/> /iscsi create iqn.2021-08.org.westos:storage1
Created target iqn.2021-08.org.westos:storage1.
Created TPG 1.
Global pref auto_add_default_portal=true
Created default portal listening on all IPs (0.0.0.0), port 3260.
/> /iscsi/iqn.2021-08.org.westos:storage1/tpg1/luns create /backstores/block/westos:storage1
Created LUN 0.
/> /iscsi/iqn.2021-08.org.westos:storage1/tpg1/acls create iqn.2021-08.org.westos:westoskey
Created Node ACL for iqn.2021-08.org.westos:westoskey
Created mapped LUN 0.
/> quit
Command not found quit
/> exit
Global pref auto_save_on_exit=true
Configuration saved to /etc/target/saveconfig.json

(2).在iscsi客户端westoslinux 172.25.254.200:

dnf install iscsi-initiator-utils-6.2.0.878-4.gitd791ce0.el8.i686 -y ##安装iscsi服务端软件

systemctl status iscsid ##对客户端配置控制服务

systemctl status iscsi ##客户端对资源利用的服务

iscsiadm -m discovery -t st -p 172.25.254.100 ##共享信息查询：-m mode，-t 指定要识别的设备属性，-p 指定资源主机ip

*******注意：如果链接100服务失败需要设定100中的火墙
//
firewall-cmd --permanent --add-port=3260/tcp
firewall-cmd --reload
//
iscsiadm -m node -T iqn.2021-08.org.westos:storage1 -p 172.25.254.100 -l ##-T 指定要访问的共享设备名称，-l 登陆共享设备
**注意：如果失败，是因为在客户端中未指定服务端的共享key所以无法登录
需要在/etc/iscsi/initiatorname.iscsi文件中指定key，然后重启服务
vim /etc/iscsi/initiatorname.iscsi
//
InitiatorName=iqn.2021-08.org.westos:westoskey
服务器中的共享key
//
systemctl restart iscsid.service

fdisk -l：查看磁盘的分区情况，子系统会出现一个新的硬盘大小为服务器中共享设备的大小
mkfs.xfs /dev/sda1 ##格式化设备为xfs文件系统，相当与在/dev/sda1上安装设备管理软件
mount /dev/sda1 /mnt/ ##挂载共享设备到/mnt/

具体操作：

[root@westoslinux ~]# dnf install iscsi-initiator-utils-6.2.0.878-4.gitd791ce0.el8.i686  -y  ##安装iscsi服务端软件
[root@westoslinux ~]# systemctl status iscsid  ##对客户端配置控制服务
● iscsid.service - Open-iSCSILoaded: loaded (/usr/lib/systemd/system/iscsid.service; disabled; vend>Active: inactive (dead)Docs: man:iscsid(8)man:iscsiuio(8)man:iscsiadm(8)[root@westoslinux ~]# systemctl status iscsi  ##客户端对资源利用的服务
● iscsi.service - Login and scanning of iSCSI devicesLoaded: loaded (/usr/lib/systemd/system/iscsi.service; enabled; vendor>Active: inactive (dead)
Condition: start condition failed at Wed 2021-08-11 09:02:05 CST; 2h 19mi>Docs: man:iscsiadm(8)man:iscsid(8)Aug 11 09:02:05 westoslinux.westos.org systemd[1]: iscsi.service: Unit ca>[root@westoslinux ~]# iscsiadm -m discovery -t st -p 172.25.254.100   ##-m mode，-t 指定要识别的设备属性，-p 指定资源主机ip
iscsiadm: cannot make connection to 172.25.254.100: No route to host
iscsiadm: cannot make connection to 172.25.254.100: No route to host
iscsiadm: cannot make connection to 172.25.254.100: No route to host
iscsiadm: cannot make connection to 172.25.254.100: No route to host   ##如果链接100服务失败需要设定100中的火墙
iscsiadm: cannot make connection to 172.25.254.100: No route to host
iscsiadm: cannot make connection to 172.25.254.100: No route to host
iscsiadm: connection login retries (reopen_max) 5 exceeded
iscsiadm: Could not perform SendTargets discovery: iSCSI PDU timed out[root@westoslinux ~]# iscsiadm -m discovery -t st -p 172.25.254.100  ##共享信息可以查询
172.25.254.100:3260,1 iqn.2021-08.org.westos:storage1
[root@westoslinux ~]# vim /etc/iscsi/initiatorname.iscsi
//
InitiatorName=iqn.2021-08.org.westos:westoskey
//
[root@westoslinux ~]# systemctl restart iscsid.service
[root@westoslinux ~]# iscsiadm -m node -T iqn.2021-08.org.westos:storage1  -p 172.25.254.100 -l  ##-T 指定要访问的共享设备名称，-l 登陆共享设备
Logging in to [iface: default, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260]
Login to [iface: default, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260] successful.[root@westoslinux ~]# fdisk -l
Disk /dev/vda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x34fd8722Device     Boot   Start      End  Sectors Size Id Type
/dev/vda1  *       2048  2099199  2097152   1G 83 Linux
/dev/vda2       2099200  6293503  4194304   2G 82 Linux swap / Solaris
/dev/vda3       6293504 41943039 35649536  17G 83 LinuxDisk /dev/sda: 2 GiB, 2147483648 bytes, 4194304 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[root@westoslinux ~]# fdisk /dev/sdaWelcome to fdisk (util-linux 2.32.1).
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.
Created a new DOS disklabel with disk identifier 0xce42a8b4.Command (m for help): n
Partition typep   primary (0 primary, 0 extended, 4 free)e   extended (container for logical partitions)
Select (default p): Using default response p.
Partition number (1-4, default 1):
First sector (2048-4194303, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-4194303, default 4194303): Created a new partition 1 of type 'Linux' and of size 2 GiB.
Partition #1 contains a ext4 signature.Do you want to remove the signature? [Y]es/[N]o: yThe signature will be removed by a write command.Command (m for help): wq
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.[root@westoslinux ~]# mkfs.xfs /dev/sda1      ##格式化设备为xfs文件系统，相当与在/dev/sda1上安装设备管理软件
meta-data=/dev/sda1              isize=512    agcount=4, agsize=131008 blks=                       sectsz=512   attr=2, projid32bit=1=                       crc=1        finobt=1, sparse=1, rmapbt=0=                       reflink=1
data     =                       bsize=4096   blocks=524032, imaxpct=25=                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2=                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@westoslinux ~]# mount /dev/sda1 /mnt/   ##挂载共享设备到/mnt/

卸载设备

客户端westoslinux 172.25.254.200主机：

tree /var/lib/iscsi/ ##在客户端读取到服务器的所有数据存放目录

iscsiadm -m node -T iqn.2021-08.org.westos:storage1 -p 172.25.254.100 -u ##-u 临时登出共享设备，再-o delete删除该设备

退出登陆后设备就消失了，但是数据还在，重启iscsi服务后设备会自动出现

iscsiadm -m node -T iqn.2021-08.org.westos:storage1 -p 172.25.254.100 -o delete ##删除客户主机中此网络设备的数据

实际操作：

[root@westoslinux ~]# umount /mnt
[root@westoslinux ~]# df
Filesystem     1K-blocks    Used Available Use% Mounted on
devtmpfs          403532       0    403532   0% /dev
tmpfs             419132       0    419132   0% /dev/shm
tmpfs             419132    6320    412812   2% /run
tmpfs             419132       0    419132   0% /sys/fs/cgroup
/dev/vda3       17814528 3369848  14444680  19% /
/dev/vda1        1038336  173172    865164  17% /boot
tmpfs              83824    1180     82644   2% /run/user/42
tmpfs              83824       4     83820   1% /run/user/0
[root@westoslinux ~]# tree /var/lib/iscsi/
/var/lib/iscsi/
├── ifaces
├── isns
├── nodes
│   └── iqn.2021-08.org.westos:storage1
│       └── 172.25.254.100,3260,1
│           └── default
├── send_targets
│   └── 172.25.254.100,3260
│       ├── iqn.2021-08.org.westos:storage1,172.25.254.100,3260,1,default -> /var/lib/iscsi/nodes/iqn.2021-08.org.westos:storage1/172.25.254.100,3260,1
│       └── st_config
├── slp
└── static10 directories, 2 files
[root@westoslinux ~]# iscsiadm -m node -T iqn.2021-08.org.westos:storage1  -p 172.25.254.100 -u
Logging out of session [sid: 1, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260]
Logout of [sid: 1, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260] successful.
[root@westoslinux ~]# fdisk -l
Disk /dev/vda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x34fd8722Device     Boot   Start      End  Sectors Size Id Type
/dev/vda1  *       2048  2099199  2097152   1G 83 Linux
/dev/vda2       2099200  6293503  4194304   2G 82 Linux swap / Solaris
/dev/vda3       6293504 41943039 35649536  17G 83 Linux
[root@westoslinux ~]# systemctl restart iscsi
[root@westoslinux ~]# tree /var/lib/iscsi/
/var/lib/iscsi/
├── ifaces
├── isns
├── nodes
│   └── iqn.2021-08.org.westos:storage1
│       └── 172.25.254.100,3260,1
│           └── default
├── send_targets
│   └── 172.25.254.100,3260
│       ├── iqn.2021-08.org.westos:storage1,172.25.254.100,3260,1,default -> /var/lib/iscsi/nodes/iqn.2021-08.org.westos:storage1/172.25.254.100,3260,1
│       └── st_config
├── slp
└── static10 directories, 2 files
[root@westoslinux ~]# fdisk -l
Disk /dev/vda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x34fd8722Device     Boot   Start      End  Sectors Size Id Type
/dev/vda1  *       2048  2099199  2097152   1G 83 Linux
/dev/vda2       2099200  6293503  4194304   2G 82 Linux swap / Solaris
/dev/vda3       6293504 41943039 35649536  17G 83 LinuxDisk /dev/sda: 2 GiB, 2147483648 bytes, 4194304 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
Disklabel type: dos
Disk identifier: 0xce42a8b4Device     Boot Start     End Sectors Size Id Type
/dev/sda1        2048 4194303 4192256   2G 83 Linux
[root@westoslinux ~]# iscsiadm -m node -T iqn.2021-08.org.westos:storage1  -p 172.25.254.100 -u
Logging out of session [sid: 2, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260]
Logout of [sid: 2, target: iqn.2021-08.org.westos:storage1, portal: 172.25.254.100,3260] successful.
[root@westoslinux ~]# iscsiadm -m node -T iqn.2021-08.org.westos:storage1  -p 172.25.254.100 -o delete
[root@westoslinux ~]# tree /var/lib/iscsi/
/var/lib/iscsi/
├── ifaces
├── isns
├── nodes
├── send_targets
│   └── 172.25.254.100,3260
│       └── st_config
├── slp
└── static7 directories, 1 file
[root@westoslinux ~]# systemctl restart iscsi
[root@westoslinux ~]# fdisk -l
Disk /dev/vda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x34fd8722Device     Boot   Start      End  Sectors Size Id Type
/dev/vda1  *       2048  2099199  2097152   1G 83 Linux
/dev/vda2       2099200  6293503  4194304   2G 82 Linux swap / Solaris
/dev/vda3       6293504 41943039 35649536  17G 83 Linux

服务端westos_strage 172.25.254.100主机：
targetcli
clearconfig confirm=True ##清空服务器中iscsi的共享数据

实际操作：

[root@westos_storage ~]# targetcli
targetcli shell version 2.1.51
Copyright 2011-2013 by Datera, Inc and others.
For help on commands, type 'help'./> ls
o- / ....................................................................................................... [...]o- backstores ............................................................................................ [...]| o- block ................................................................................ [Storage Objects: 1]| | o- westos:storage1 ............................................... [/dev/vdb1 (2.0GiB) write-thru activated]| |   o- alua ................................................................................. [ALUA Groups: 1]| |     o- default_tg_pt_gp ..................................................... [ALUA state: Active/optimized]| o- fileio ............................................................................... [Storage Objects: 0]| o- pscsi ................................................................................ [Storage Objects: 0]| o- ramdisk .............................................................................. [Storage Objects: 0]o- iscsi .......................................................................................... [Targets: 1]| o- iqn.2021-08.org.westos:storage1 ................................................................. [TPGs: 1]|   o- tpg1 ............................................................................. [no-gen-acls, no-auth]|     o- acls ........................................................................................ [ACLs: 1]|     | o- iqn.2021-08.org.westos:westoskey ................................................... [Mapped LUNs: 1]|     |   o- mapped_lun0 ..................................................... [lun0 block/westos:storage1 (rw)]|     o- luns ........................................................................................ [LUNs: 1]|     | o- lun0 ......................................... [block/westos:storage1 (/dev/vdb1) (default_tg_pt_gp)]|     o- portals .................................................................................. [Portals: 1]|       o- 0.0.0.0:3260 ................................................................................... [OK]o- loopback ....................................................................................... [Targets: 0]
/> clearconfig confirm=True
All configuration cleared
/> exit
Global pref auto_save_on_exit=true
Last 10 configs saved in /etc/target/backup/.
Configuration saved to /etc/target/saveconfig.json