server端准备：
fdisk -l /dev/vdb-------新建分区
（建议+2G）
partprobe-------刷新分区表
yum install targetrcli -y---------安装服务
systemctl start target---------打开服务
systemctl enable target---------开机启动
systemctl stop firewalld---------关闭火墙
[root@samba ~]# targetcli ##进入交互模式##
Warning: Could not load preferences file /root/.targetcli/prefs.bin.
targetcli shell version 2.1.fb34
Copyright 2011-2013 by Datera, Inc and others.
For help on commands, type ‘help‘.
/> ls ##列出/目录下的文件目录##
o- / ................................................. [...]
o- backstores ...................................... [...]
| o- block .......................... [Storage Objects: 0]
| o- fileio ......................... [Storage Objects: 0]
| 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 ##给设备/dev/vdb1一个别名（westos：storage1）##
Created block storage object westos:storage1 using /dev/vdb1.
/> /iscsi create iqn.2017-03.com.westos.storage1 ##生成设备共享文件##
Created target iqn.2017-03.com.westos.storage1.
Created TPG 1.
/> /iscsi/iqn.2017-03.com.westos.storage1/tpg1/acls create iqn.2017-03.com.westos:key1 ##给共享设备生成一个key1##
Created Node ACL for iqn.2017-03.com.westos:key1
/> /iscsi/iqn.2017-03.com.westos.storage1/tpg1/luns create /backstores/block/westos:storage1 ##将该别名和共享设备关联起来，设备别名必须使用绝对路径##
Created LUN 0.
Created LUN 0->0 mapping in node ACL iqn.2017-03.com.westos:key1
/> /iscsi/iqn.2017-03.com.westos.storage1/tpg1/portals create 172.25.254.137 ##开放端口##
Using default IP port 3260
Created network portal 172.25.254.137:3260.
/> exit ##退出交互模式##
Global pref auto_save_on_exit=true
Last 10 configs saved in /etc/target/backup.
Configuration saved to /etc/target/saveconfig.json
[root@samba ~]#
客户端：
yum install iscsi-initiator-utils.i686 -y-------安装软件包
systemctl start iscsi--------启动服务
注：iscsid服务是管理现在的，如果iscsi总是起不来，启动iscsid服务也是可以的
vim /etc/iscsi/initiatorname.iscsi---------编写iscsi的一个相关配置文件，写入server端的key
systemctl reset iscsi--------重启iscsi服务
iscsiadm 命令：
-l --login ##登陆节点（服务器）##
-p --portal=ip[:port] #指定target服务的IP和端口（ping IP）##
-T --targetname=targetname ##用于指定target的名字##
-u --logout ##登出节点（服务器）##
-o --op=OPEARTION ##指定针对discoverydb数据库的操作，其仅能为new、delete、update、show和nonpersistent其中之一##
-m --mode op ##可用的mode有discovery, node, fw, host iface 和 session##
-t --type ##这里可以使用的类型为sendtargets(可简写为st)、slp、fw和 isns，此选项仅用于discovery模式，且目前仅支持st、fw和isns；其中st表示允许每个iSCSItarget发送一个可用target列表给initiator##
例如：
iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -p 172.25.254.137 -l
iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -u
iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -o delete
client的实际操作：
[root@client ~]# systemctl start iscsi ##开启iscsi服务##
Warning: Unit file of iscsi.service changed on disk, ‘systemctl daemon-reload‘ recommended. ##iscsi服务开启报错，要求执行“systemctl daemon-reload”命令##
[root@client ~]# systemctl daemon-reload
[root@client ~]# systemctl start iscsi
[root@client ~]# vim /etc/iscsi/initiatorname.iscsi ##编写iscsi的一个配置文件##
[root@client ~]# cat /etc/iscsi/initiatorname.iscsi
InitiatorName=iqn.2017-03.com.westos:key1 ##server端的key##
[root@client ~]# systemctl restart iscsi ##重启iscsi服务##
[root@client ~]# iscsiadm -m discovery -t st -p 172.25.254.137 ##发现server端可共享的设备##
[root@client ~]# iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -p 172.25.254.137 -l ##连接server端的共享设备##
Logging in to [iface: default, target: iqn.2017-03.com.westos.storage1, portal: 172.25.254.137,3260] (multiple)
Login to [iface: default, target: iqn.2017-03.com.westos.storage1, portal: 172.25.254.137,3260] successful.
[root@client ~]# fdisk -l ##查看分区列表##
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 sectors ##client原有设备/dev/vda##
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: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 20970332 10484142+ 83 Linux
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 sectors ##client原有设备/dev/vdb##
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 /dev/sda: 2147 MB, 2147483648 bytes, 4194304 sectors ##/dev/sda是client连接到的server端所共享的设备##
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 4194304 bytes
[root@client ~]# fdisk /dev/sda ##在磁盘/dev/sda上分区##
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 0x0b4727ba.
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 (8192-4194303, default 8192):
Using default value 8192
Last sector, +sectors or +size{K,M,G} (8192-4194303, default 4194303): +1G
Partition 1 of type Linux and of size 1 GiB is set
Command (m for help): wq
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@client ~]# fdisk -l
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 20970332 10484142+ 83 Linux
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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 /dev/sda: 2147 MB, 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 / 4194304 bytes
Disk label type: dos
Disk identifier: 0x0b4727ba
Device Boot Start End Blocks Id System
/dev/sda1 8192 2105343 1048576 83 Linux
[root@client ~]# mount /dev/sda1 /mnt ##将设备/dev/sda1挂载到目录/mnt##
mount: /dev/sda1 is write-protected, mounting read-only
mount: unknown filesystem type ‘(null)‘
[root@client ~]# mkfs.xfs /dev/sda1 ##格式化/dev/sda1##
meta-data=/dev/sda1 isize=256 agcount=8, agsize=32768 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=262144, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
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@client ~]# mount /dev/sda1 /mnt ##挂载设备##
[root@client ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/vda1 10473900 3226672 7247228 31% /
devtmpfs 493408 0 493408 0% /dev
tmpfs 508996 140 508856 1% /dev/shm
tmpfs 508996 13348 495648 3% /run
tmpfs 508996 0 508996 0% /sys/fs/cgroup
//172.25.254.137/westos 1038336 33056 1005280 4% /mnt ##挂载失败##
[root@client ~]# umount /mnt ##卸载原设备##
[root@client ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/vda1 10473900 3226672 7247228 31% /
devtmpfs 493408 0 493408 0% /dev
tmpfs 508996 140 508856 1% /dev/shm
tmpfs 508996 13348 495648 3% /run
tmpfs 508996 0 508996 0% /sys/fs/cgroup
[root@client ~]# mount /dev/sda1 /mnt ##再次挂载##
[root@client ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/vda1 10473900 3226672 7247228 31% /
devtmpfs 493408 0 493408 0% /dev
tmpfs 508996 140 508856 1% /dev/shm
tmpfs 508996 13348 495648 3% /run
tmpfs 508996 0 508996 0% /sys/fs/cgroup
/dev/sda1 1038336 33056 1005280 4% /mnt ##挂载成功##
[root@client ~]# umount /mnt ##卸载/mnt##
[root@client ~]# iscsiadm -m discovery -t st -p 172.25.254.137 ##发现172.25.254.137的共享文件##
172.25.254.137:3260,1 iqn.2017-03.com.westos.storage1
[root@client ~]# iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -u ##登出iscsi目标，以暂时断开连接##
Logging out of session [sid: 1, target: iqn.2017-03.com.westos.storage1, portal: 172.25.254.137,3260]
Logout of [sid: 1, target: iqn.2017-03.com.westos.storage1, portal: 172.25.254.137,3260] successful.
[root@client ~]# fdisk -l
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 20970332 10484142+ 83 Linux
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 by ##/dev/sda1删除成功##
[root@client ~]# systemctl restart iscsi ##重启iscsi服务##
[root@client ~]# fdisk -l
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 20970332 10484142+ 83 Linux
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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 /dev/sda: 2147 MB, 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 / 4194304 bytes
Disk label type: dos
Disk identifier: 0x0b4727ba
Device Boot Start End Blocks Id System ##/dev/sda1有回来了##
/dev/sda1 8192 2105343 1048576 83 Linux
[root@client ~]# iscsiadm -m node -T iqn.2017-03.com.westos.storage1 -o delete ##删除client接收到的server端的共享##
[root@client ~]# systemctl restart iscsi
[root@client ~]# fdisk -l
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 20970332 10484142+ 83 Linux
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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 ##重启iscsi服务后，/dev/sda1并未回来，删除成功##
原文：http://12459513.blog.51cto.com/12449513/1908219