第一步：服务端 target
1、配置ip地址，关闭iptables 和selinux
[root@localhost Desktop]# ifconfig eth0 10.0.0.1 netmask 255.0.0.0
[root@localhost Desktop]# service iptables stop
i
[root@localhost Desktop]# setenforce 0
2、软件安装
[root@localhost Desktop]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# ll
total 16
-rw-r--r--. 1 root root 1926 Nov 27 2013 CentOS-Base.repo
-rw-r--r--. 1 root root 638 Nov 27 2013 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root 630 Nov 27 2013 CentOS-Media.repo
-rw-r--r--. 1 root root 3664 Nov 27 2013 CentOS-Vault.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Base.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Debuginfo.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Vault.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# ll
total 4
-rw-r--r--. 1 root root 630 Nov 27 2013 CentOS-Media.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# vim CentOS-Media.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# tail -6 CentOS-Media.repo
[c6-media]
name=CentOS-$releasever - Media
baseurl=file:///mnt
gpgcheck=0
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# mount /dev/sr0 /mnt
mount: block device /dev/sr0 is write-protected, mounting read-only
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# yum clean all
Loaded plugins: fastestmirror, refresh-packagekit, security
Cleaning repos: c6-media
Cleaning up Everything
[root@localhost yum.repos.d]#
安装软件scsi-target-utils
[root@localhost ~]#
[root@localhost ~]# yum -y install scsi-target-utils
[root@localhost ~]# rpm -qa |grep scsi
scsi-target-utils-1.0.24-10.el6.x86_64
[root@localhost ~]#
3、添加硬盘，配置本地存储系统提供远程访问
[root@localhost ~]#
[root@localhost ~]# fdisk /dev/sdb //注意只分区，而不格式化。格式化留给使用的客户端自己去格式化
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -5 /etc/tgt/targets.conf
<target iqn.2015-11.com.sohu:san1> //表示IQN号,可以随便取,但是要遵循这个格式（这个格式必须这样子，网址倒着写）
vendor_id sohu //说明id号，无所谓的东西
backing-store /dev/sdb //提供ISCSI服务的硬盘分区.
initiator-address 10.0.0.2 //指定允许访问的客户端ip（表示允许这两个IP的地址访问SCSI磁盘.）
</target>
[root@localhost ~]#
[root@localhost ~]#
5、强scsi服务器端启动并设置开机自动启动
root@localhost ~]#
[root@localhost ~]# service tgtd start
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
[root@localhost ~]# service tgtd status
tgtd (pid 13150 13148) is running...
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# chkconfig tgtd on //设置开机自动启动
[root@localhost ~]#
[root@localhost ~]# netstat -antup |grep 3260 //tgtd的端口号为3260
tcp 0 0 0.0.0.0:3260 0.0.0.0:* LISTEN 13148/tgtd
tcp 0s 0 :::3260 :::* LISTEN 13148/tgtd
[root@localhost ~]#
第二步：配置客户端 initaitor
1、配置ip，iptables selinux、
[root@localhost Desktop]# ifconfig eth0 10.0.0.2 netmask 255.0.0.0
[root@localhost Desktop]# ip a
[root@localhost Desktop]# service iptables stop
[root@localhost Desktop]# setenforce 0
2、安装客户端软件
[root@localhost Desktop]# rpm -ivh /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm
warning: /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [100%]
1:iscsi-initiator-utils ########################################### [100%]
[root@localhost Desktop]#
[root@localhost Desktop]# rpm -qa |grep iscsi
iscsi-initiator-utils-6.2.0.873-10.el6.x86_64
[root@localhost Desktop]#
3、使用iscsi发现目标
注意：各种启动没成功，因为需要先发现再启
[root@localhost ~]# service iscsid restart
Stopping iscsid:
[root@localhost ~]# [FAILED]
[root@localhost ~]# service iscsid start //各种启动没成功，因为需要先发现再启动
[root@localhost ~]# service iscsid status
iscsid is stopped
[root@localhost ~]#
iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
iscsiadm --mode discoverydb --type sendtargets --portal 10.0.0.1 –discover
[root@localhost ~]#
[root@localhost ~]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260 //发现目标。过程自动启动iscsid服务
Starting iscsid: [ OK ]
10.0.0.1:3260,1 iqn.2015-11.com.sohu:san1
[root@localhost ~]#
[root@localhost ~]# service iscsid status //服务处于启动状态。在发现目标是自动启动的。
iscsid (pid 2778) is running...
[root@localhost ~]#
[root@localhost ~]# chkconfig iscsid on //设置开启自动启动
[root@localhost ~]# service iscsi start
[root@localhost ~]# chkconfig iscsi on //设置开启自动启动
注意：只有iscsi和iscsid都启动了，才能看到，服务器共享出来的硬盘 sdb
[root@localhost ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 26 00:19 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 26 00:19 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 26 00:19 /dev/sda2
brw-rw----. 1 root disk 8, 3 Nov 26 00:19 /dev/sda3
brw-rw----. 1 root disk 8, 16 Nov 26 01:36 /dev/sdb
brw-rw----. 1 root disk 8, 17 Nov 26 01:36 /dev/sdb1
[root@localhost ~]#
4、格式化挂载使用
[root@localhost ~]#
[root@localhost ~]# mkdir /wt
[root@localhost ~]# mount /dev/sdb /wt
mount: you must specify the filesystem type
[root@localhost ~]#
[root@localhost ~]# mkfs.ext4 /dev/sdb
mke2fs 1.41.12 (17-May-2010)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
65536 inodes, 262144 blocks
13107 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=268435456
8 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 34 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
[root@localhost ~]# mount /dev/sdb /wt
[root@localhost ~]# ll /wt/
total 16
drwx------. 2 root root 16384 Nov 26 02:23 lost+found
[root@localhost ~]#
[root@localhost ~]# cp -r /etc/passwd /wt
[root@localhost ~]# ll /wt
total 20
drwx------. 2 root root 16384 Nov 26 02:23 lost+found
-rw-r--r--. 1 root root 1423 Nov 26 02:24 passwd
[root@localhost]#
查看uuid号用于开机自动挂载磁盘。因为sdb会由变动（比如，插入u就默认sdb），而uuid一直是不变的。
[root@localhost ~]#
[root@localhost ~]# blkid /dev/sdb
/dev/sdb: UUID="c2a254fa-6ab5-4c85-a756-c8bf8c7242f4" TYPE="ext4"
[root@localhost ~]#
[root@localhost ~]# vim /etc/fstab //设置开机自动挂载
[root@localhost ~]# tail -1 !$
UUID="c2a254fa-6ab5-4c85-a756-c8bf8c7242f4" /wt ext4 _netdev 0 0
[root@localhost ~]#
注意，重启的时候要登出，不然，重启动系统的话会报错,导致很长时间起不来电脑
[root@localhost ~]#
[root@localhost ~]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost ~]#
[root@localhost ~]#
！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！
如下为登入命令。可以不用
[root@localhost ~]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --login
[root@localhost ~]#
！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！
重启后，看是否能正常启动和挂载，并开启服务
[root@localhost ~]# reboot
再看挂载ok，启动正常。数据依然在
[root@localhost Desktop]# tree /usr/bin/which
/usr/bin/which [error opening dir]
0 directories, 0 files
[root@localhost Desktop]# tree /var/lib/iscsi
/var/lib/iscsi
├── ifaces
├── isns
├── nodes
│?? └── iqn.2015-11.com.sohu:san1
│?? └── 10.0.0.1,3260,1
│?? └── default
├── send_targets
│?? └── 10.0.0.1,3260
│?? ├── iqn.2015-11.com.sohu:san1,10.0.0.1,3260,1,default -> /var/lib/iscsi/nodes/iqn.2015-11.com.sohu:san1/10.0.0.1,3260,1
│?? └── st_config
├── slp
└── static
10 directories, 2 files
[root@localhost Desktop]#
[root@localhost Desktop]#
##################################################################################################
卸载，挂载存储设备
1、卸载
如果，卸载不成功的话，将所有都卸了再挂载后（umount -a /mount -a）。用下面命令登出
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost Desktop]#
/dev/sdc 1032088 34056 945604 4% /wt
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -l
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost Desktop]#
总结：
卸载
卸载的时候，要先登出，否则下次启动的时候起不来，或启动慢。
登出：iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u 或 iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
这时候查看就没有挂载也没有共享的磁盘
挂载
方法一：重启即可自动挂载
方法二：先发现，再登入，最后挂载即可
发现：iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
登入：iscsiadm -m node -T iqn.2008-09.com.sohu:wt -l
卸载重新挂载：umount -a mount -a
详细如下：
root@localhost wt]#
[root@localhost wt]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
10.0.0.1:3260,1 iqn.2008-09.com.sohu:wt
[root@localhost wt]#
[root@localhost wt]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 8985528 2526196 6002884 30% /
tmpfs 502204 224 501980 1% /dev/shm
/dev/sdb 1032088 34056 945604 4% /wt
[root@localhost wt]#
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]#
[root@localhost wt]# mount -a
mount: special device UUID="106f7acc-ce28-4cf7-a5d7-1b18f4e8f6ed" does not exist
[root@localhost wt]#
[root@localhost wt]# umount -a
umount: /wt: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /var/run/vmblock-fuse: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@localhost wt]# mount -a
mount: special device UUID="106f7acc-ce28-4cf7-a5d7-1b18f4e8f6ed" does not exist
[root@localhost wt]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 8985528 2526188 6002892 30% /
tmpfs 502204 224 501980 1% /dev/shm
/dev/sdb 1032088 34056 945604 4% /wt
/dev/sda1 297485 34642 247483 13% /boot
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]# iscsiadm -m node -T iqn.2008-09.com.sohu:wt -l
Logging in to [iface: default, target: iqn.2008-09.com.sohu:wt, portal: 10.0.0.1,3260] (multiple)
Login to [iface: default, target: iqn.2008-09.com.sohu:wt, portal: 10.0.0.1,3260] successful.
[root@localhost wt]#
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]# mount -a
[root@localhost wt]# ll
ls: reading directory .: Input/output error
total 0
[root@localhost wt]# cd
[root@localhost ~]# umount -a
umount: /var/run/vmblock-fuse: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@localhost ~]#
[root@localhost ~]# mount -a
[root@localhost ~]#
[root@localhost ~]# ll
total 100
-rw-------. 1 root root 3322 Nov 4 08:55 anaconda-ks.cfg
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Desktop
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Documents
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Downloads
-rw-r--r--. 1 root root 41364 Nov 4 08:55 install.log
-rw-r--r--. 1 root root 15643 Nov 4 08:55 install.log.syslog
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Music
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Pictures
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Public
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Templates
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Videos
[root@localhost ~]# ll /wt
total 20
drwx------. 2 root root 16384 Dec 6 06:01 lost+found
-rw-r--r--. 1 root root 1429 Dec 6 06:01 passwd
[root@localhost ~]#
[root@localhost ~]#
#########################################################################################
target 删除了磁盘sdb，共享新盘sdc，客户端需要重新发现
1、服务端，target
删除原有磁盘，再添加新盘sdc
首先，客户端闲载
[root@localhost iscsi]#
[root@localhost iscsi]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
或
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u
target端，添加硬盘sdc，并配置tgta服务
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -6 !$
tail -6 /etc/tgt/targets.conf
#</target>
<target iqn.2015-11.com.sohu:san1>
vendor_id sohu
backing-store /dev/sdc
initiator-address 10.0.0.2
</target>
[root@localhost ~]#
客户端 initiator（发起者）
[root@localhost iscsi]#
[root@localhost iscsi]# service iscsi stop
Stopping iscsi: [ OK ]
[root@localhost iscsi]#
[root@localhost iscsi]#
[root@localhost iscsi]# ll
total 24
drwxr-xr-x. 2 root root 4096 Nov 23 2013 ifaces
drwxr-xr-x. 2 root root 4096 Nov 23 2013 isns
drwxr-xr-x. 3 root root 4096 Nov 26 01:20 nodes
drwxr-xr-x. 3 root root 4096 Nov 26 01:20 send_targets
drwxr-xr-x. 2 root root 4096 Nov 23 2013 slp
drwxr-xr-x. 2 root root 4096 Nov 23 2013 static
[root@localhost iscsi]# rm -rf /var/lib/iscsi/*
[root@localhost iscsi]# ll
total 0
[root@localhost iscsi]#
[root@localhost iscsi]# service iscsi start
Starting iscsi: [ OK ]
[root@localhost iscsi]#
[root@localhost ~]#
[root@localhost ~]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
10.0.0.1:3260,1 iqn.2015-11.com.sohu:san1
[root@localhost ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 26 02:56 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 26 02:56 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 26 02:56 /dev/sda2
brw-rw----. 1 root disk 8, 3 Nov 26 02:56 /dev/sda3
brw-rw----. 1 root disk 8, 32 Nov 26 05:21 /dev/sdc
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# mkfs.ext4 /dev/sdc
[root@localhost ~]# umount -a
[root@localhost ~]# mount /dev/sdc /wt
[root@localhost ~]# ll /wt/
total 16
drwx------. 2 root root 16384 Nov 26 05:23 lost+found
[root@localhost ~]#
#########################################################################################################3
在target服务端，再添加几个存储客户端，并实现同步数据。
1、在target服务端
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -6 /etc/tgt/targets.conf
<target iqn.2015-11.com.sohu:san1>
vendor_id sohu
backing-store /dev/sdc
initiator-address 10.0.0.2
initiator-address 10.0.0.3
</target>
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# /etc/init.d/tgtd restart
Stopping SCSI target daemon: initiators still connected [FAILED]
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
或
[root@localhost ~]# service tgtd restart
Stopping SCSI target daemon: [ OK ]
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
[root@localhost ~]#
2、再开2台客户端。
10.0.0.3
10.0.0.4
[root@localhost Desktop]#
[root@localhost Desktop]# rpm -vih /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm
warning: /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [100%]
1:iscsi-initiator-utils ########################################### [100%]
[root@localhost Desktop]#
[root@localhost Desktop]# mkdir /wt
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
Starting iscsid: [ OK ]
iscsiadm: No portals found
[root@localhost Desktop]#
root@localhost ~]# mount /dev/sdb /wt
[root@localhost ~]# ll /wt/
total 36
drwxr-xr-x. 2 root root 4096 Nov 26 09:52 22
drwxr-xr-x. 2 root root 4096 Nov 26 09:52 2222
drwxr-xr-x. 2 root root 4096 Nov 26 09:45 3
drwxr-xr-x. 2 root root 4096 Nov 26 09:49 33
drwxr-xr-x. 2 root root 4096 Nov 26 09:59 44444
-rw-r--r--. 1 root root 0 Nov 26 09:42 a
drwx------. 2 root root 16384 Nov 26 09:41 lost+found
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
总结，在10.0.0.2 10.0.0.3 10.0.0.4 上面分别挂载创建文件，如上，10.0.0.2创建22.2222.10.0.0.3创建3.33，依次来区分。然后，分别在各个系统上卸载后重新挂载，发现数据同步了。
1、配置ip地址，关闭iptables 和selinux
[root@localhost Desktop]# ifconfig eth0 10.0.0.1 netmask 255.0.0.0
[root@localhost Desktop]# service iptables stop
i
[root@localhost Desktop]# setenforce 0
2、软件安装
[root@localhost Desktop]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# ll
total 16
-rw-r--r--. 1 root root 1926 Nov 27 2013 CentOS-Base.repo
-rw-r--r--. 1 root root 638 Nov 27 2013 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root 630 Nov 27 2013 CentOS-Media.repo
-rw-r--r--. 1 root root 3664 Nov 27 2013 CentOS-Vault.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Base.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Debuginfo.repo
[root@localhost yum.repos.d]# rm -rf CentOS-Vault.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# ll
total 4
-rw-r--r--. 1 root root 630 Nov 27 2013 CentOS-Media.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# vim CentOS-Media.repo
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# tail -6 CentOS-Media.repo
[c6-media]
name=CentOS-$releasever - Media
baseurl=file:///mnt
gpgcheck=0
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# mount /dev/sr0 /mnt
mount: block device /dev/sr0 is write-protected, mounting read-only
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# yum clean all
Loaded plugins: fastestmirror, refresh-packagekit, security
Cleaning repos: c6-media
Cleaning up Everything
[root@localhost yum.repos.d]#
安装软件scsi-target-utils
[root@localhost ~]#
[root@localhost ~]# yum -y install scsi-target-utils
[root@localhost ~]# rpm -qa |grep scsi
scsi-target-utils-1.0.24-10.el6.x86_64
[root@localhost ~]#
3、添加硬盘，配置本地存储系统提供远程访问
[root@localhost ~]#
[root@localhost ~]# fdisk /dev/sdb //注意只分区，而不格式化。格式化留给使用的客户端自己去格式化
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -5 /etc/tgt/targets.conf
<target iqn.2015-11.com.sohu:san1> //表示IQN号,可以随便取,但是要遵循这个格式（这个格式必须这样子，网址倒着写）
vendor_id sohu //说明id号，无所谓的东西
backing-store /dev/sdb //提供ISCSI服务的硬盘分区.
initiator-address 10.0.0.2 //指定允许访问的客户端ip（表示允许这两个IP的地址访问SCSI磁盘.）
</target>
[root@localhost ~]#
[root@localhost ~]#
5、强scsi服务器端启动并设置开机自动启动
root@localhost ~]#
[root@localhost ~]# service tgtd start
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
[root@localhost ~]# service tgtd status
tgtd (pid 13150 13148) is running...
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# chkconfig tgtd on //设置开机自动启动
[root@localhost ~]#
[root@localhost ~]# netstat -antup |grep 3260 //tgtd的端口号为3260
tcp 0 0 0.0.0.0:3260 0.0.0.0:* LISTEN 13148/tgtd
tcp 0s 0 :::3260 :::* LISTEN 13148/tgtd
[root@localhost ~]#
第二步：配置客户端 initaitor
1、配置ip，iptables selinux、
[root@localhost Desktop]# ifconfig eth0 10.0.0.2 netmask 255.0.0.0
[root@localhost Desktop]# ip a
[root@localhost Desktop]# service iptables stop
[root@localhost Desktop]# setenforce 0
2、安装客户端软件
[root@localhost Desktop]# rpm -ivh /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm
warning: /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [100%]
1:iscsi-initiator-utils ########################################### [100%]
[root@localhost Desktop]#
[root@localhost Desktop]# rpm -qa |grep iscsi
iscsi-initiator-utils-6.2.0.873-10.el6.x86_64
[root@localhost Desktop]#
3、使用iscsi发现目标
注意：各种启动没成功，因为需要先发现再启
[root@localhost ~]# service iscsid restart
Stopping iscsid:
[root@localhost ~]# [FAILED]
[root@localhost ~]# service iscsid start //各种启动没成功，因为需要先发现再启动
[root@localhost ~]# service iscsid status
iscsid is stopped
[root@localhost ~]#
iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
iscsiadm --mode discoverydb --type sendtargets --portal 10.0.0.1 –discover
[root@localhost ~]#
[root@localhost ~]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260 //发现目标。过程自动启动iscsid服务
Starting iscsid: [ OK ]
10.0.0.1:3260,1 iqn.2015-11.com.sohu:san1
[root@localhost ~]#
[root@localhost ~]# service iscsid status //服务处于启动状态。在发现目标是自动启动的。
iscsid (pid 2778) is running...
[root@localhost ~]#
[root@localhost ~]# chkconfig iscsid on //设置开启自动启动
[root@localhost ~]# service iscsi start
[root@localhost ~]# chkconfig iscsi on //设置开启自动启动
注意：只有iscsi和iscsid都启动了，才能看到，服务器共享出来的硬盘 sdb
[root@localhost ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 26 00:19 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 26 00:19 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 26 00:19 /dev/sda2
brw-rw----. 1 root disk 8, 3 Nov 26 00:19 /dev/sda3
brw-rw----. 1 root disk 8, 16 Nov 26 01:36 /dev/sdb
brw-rw----. 1 root disk 8, 17 Nov 26 01:36 /dev/sdb1
[root@localhost ~]#
4、格式化挂载使用
[root@localhost ~]#
[root@localhost ~]# mkdir /wt
[root@localhost ~]# mount /dev/sdb /wt
mount: you must specify the filesystem type
[root@localhost ~]#
[root@localhost ~]# mkfs.ext4 /dev/sdb
mke2fs 1.41.12 (17-May-2010)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
65536 inodes, 262144 blocks
13107 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=268435456
8 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 34 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
[root@localhost ~]# mount /dev/sdb /wt
[root@localhost ~]# ll /wt/
total 16
drwx------. 2 root root 16384 Nov 26 02:23 lost+found
[root@localhost ~]#
[root@localhost ~]# cp -r /etc/passwd /wt
[root@localhost ~]# ll /wt
total 20
drwx------. 2 root root 16384 Nov 26 02:23 lost+found
-rw-r--r--. 1 root root 1423 Nov 26 02:24 passwd
[root@localhost]#
查看uuid号用于开机自动挂载磁盘。因为sdb会由变动（比如，插入u就默认sdb），而uuid一直是不变的。
[root@localhost ~]#
[root@localhost ~]# blkid /dev/sdb
/dev/sdb: UUID="c2a254fa-6ab5-4c85-a756-c8bf8c7242f4" TYPE="ext4"
[root@localhost ~]#
[root@localhost ~]# vim /etc/fstab //设置开机自动挂载
[root@localhost ~]# tail -1 !$
UUID="c2a254fa-6ab5-4c85-a756-c8bf8c7242f4" /wt ext4 _netdev 0 0
[root@localhost ~]#
注意，重启的时候要登出，不然，重启动系统的话会报错,导致很长时间起不来电脑
[root@localhost ~]#
[root@localhost ~]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost ~]#
[root@localhost ~]#
！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！
如下为登入命令。可以不用
[root@localhost ~]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --login
[root@localhost ~]#
！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！
重启后，看是否能正常启动和挂载，并开启服务
[root@localhost ~]# reboot
再看挂载ok，启动正常。数据依然在
[root@localhost Desktop]# tree /usr/bin/which
/usr/bin/which [error opening dir]
0 directories, 0 files
[root@localhost Desktop]# tree /var/lib/iscsi
/var/lib/iscsi
├── ifaces
├── isns
├── nodes
│?? └── iqn.2015-11.com.sohu:san1
│?? └── 10.0.0.1,3260,1
│?? └── default
├── send_targets
│?? └── 10.0.0.1,3260
│?? ├── iqn.2015-11.com.sohu:san1,10.0.0.1,3260,1,default -> /var/lib/iscsi/nodes/iqn.2015-11.com.sohu:san1/10.0.0.1,3260,1
│?? └── st_config
├── slp
└── static
10 directories, 2 files
[root@localhost Desktop]#
[root@localhost Desktop]#
##################################################################################################
卸载，挂载存储设备
1、卸载
如果，卸载不成功的话，将所有都卸了再挂载后（umount -a /mount -a）。用下面命令登出
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost Desktop]#
/dev/sdc 1032088 34056 945604 4% /wt
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -l
Logging out of session [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260]
Logout of [sid: 2, target: iqn.2015-11.com.sohu:san1, portal: 10.0.0.1,3260] successful.
[root@localhost Desktop]#
总结：
卸载
卸载的时候，要先登出，否则下次启动的时候起不来，或启动慢。
登出：iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u 或 iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
这时候查看就没有挂载也没有共享的磁盘
挂载
方法一：重启即可自动挂载
方法二：先发现，再登入，最后挂载即可
发现：iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
登入：iscsiadm -m node -T iqn.2008-09.com.sohu:wt -l
卸载重新挂载：umount -a mount -a
详细如下：
root@localhost wt]#
[root@localhost wt]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
10.0.0.1:3260,1 iqn.2008-09.com.sohu:wt
[root@localhost wt]#
[root@localhost wt]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 8985528 2526196 6002884 30% /
tmpfs 502204 224 501980 1% /dev/shm
/dev/sdb 1032088 34056 945604 4% /wt
[root@localhost wt]#
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]#
[root@localhost wt]# mount -a
mount: special device UUID="106f7acc-ce28-4cf7-a5d7-1b18f4e8f6ed" does not exist
[root@localhost wt]#
[root@localhost wt]# umount -a
umount: /wt: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /var/run/vmblock-fuse: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@localhost wt]# mount -a
mount: special device UUID="106f7acc-ce28-4cf7-a5d7-1b18f4e8f6ed" does not exist
[root@localhost wt]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 8985528 2526188 6002892 30% /
tmpfs 502204 224 501980 1% /dev/shm
/dev/sdb 1032088 34056 945604 4% /wt
/dev/sda1 297485 34642 247483 13% /boot
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]# iscsiadm -m node -T iqn.2008-09.com.sohu:wt -l
Logging in to [iface: default, target: iqn.2008-09.com.sohu:wt, portal: 10.0.0.1,3260] (multiple)
Login to [iface: default, target: iqn.2008-09.com.sohu:wt, portal: 10.0.0.1,3260] successful.
[root@localhost wt]#
[root@localhost wt]# ll /wt
ls: reading directory /wt: Input/output error
total 0
[root@localhost wt]# mount -a
[root@localhost wt]# ll
ls: reading directory .: Input/output error
total 0
[root@localhost wt]# cd
[root@localhost ~]# umount -a
umount: /var/run/vmblock-fuse: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
umount: /: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@localhost ~]#
[root@localhost ~]# mount -a
[root@localhost ~]#
[root@localhost ~]# ll
total 100
-rw-------. 1 root root 3322 Nov 4 08:55 anaconda-ks.cfg
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Desktop
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Documents
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Downloads
-rw-r--r--. 1 root root 41364 Nov 4 08:55 install.log
-rw-r--r--. 1 root root 15643 Nov 4 08:55 install.log.syslog
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Music
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Pictures
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Public
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Templates
drwxr-xr-x. 2 root root 4096 Nov 4 09:01 Videos
[root@localhost ~]# ll /wt
total 20
drwx------. 2 root root 16384 Dec 6 06:01 lost+found
-rw-r--r--. 1 root root 1429 Dec 6 06:01 passwd
[root@localhost ~]#
[root@localhost ~]#
#########################################################################################
target 删除了磁盘sdb，共享新盘sdc，客户端需要重新发现
1、服务端，target
删除原有磁盘，再添加新盘sdc
首先，客户端闲载
[root@localhost iscsi]#
[root@localhost iscsi]# iscsiadm --mode node --targetname iqn.2015-11.com.sohu:san1 --portal 10.0.0.1:3260 --logout
或
[root@localhost Desktop]# iscsiadm -m node -T iqn.2015-11.com.sohu:san1 -u
target端，添加硬盘sdc，并配置tgta服务
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -6 !$
tail -6 /etc/tgt/targets.conf
#</target>
<target iqn.2015-11.com.sohu:san1>
vendor_id sohu
backing-store /dev/sdc
initiator-address 10.0.0.2
</target>
[root@localhost ~]#
客户端 initiator（发起者）
[root@localhost iscsi]#
[root@localhost iscsi]# service iscsi stop
Stopping iscsi: [ OK ]
[root@localhost iscsi]#
[root@localhost iscsi]#
[root@localhost iscsi]# ll
total 24
drwxr-xr-x. 2 root root 4096 Nov 23 2013 ifaces
drwxr-xr-x. 2 root root 4096 Nov 23 2013 isns
drwxr-xr-x. 3 root root 4096 Nov 26 01:20 nodes
drwxr-xr-x. 3 root root 4096 Nov 26 01:20 send_targets
drwxr-xr-x. 2 root root 4096 Nov 23 2013 slp
drwxr-xr-x. 2 root root 4096 Nov 23 2013 static
[root@localhost iscsi]# rm -rf /var/lib/iscsi/*
[root@localhost iscsi]# ll
total 0
[root@localhost iscsi]#
[root@localhost iscsi]# service iscsi start
Starting iscsi: [ OK ]
[root@localhost iscsi]#
[root@localhost ~]#
[root@localhost ~]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
10.0.0.1:3260,1 iqn.2015-11.com.sohu:san1
[root@localhost ~]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Nov 26 02:56 /dev/sda
brw-rw----. 1 root disk 8, 1 Nov 26 02:56 /dev/sda1
brw-rw----. 1 root disk 8, 2 Nov 26 02:56 /dev/sda2
brw-rw----. 1 root disk 8, 3 Nov 26 02:56 /dev/sda3
brw-rw----. 1 root disk 8, 32 Nov 26 05:21 /dev/sdc
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# mkfs.ext4 /dev/sdc
[root@localhost ~]# umount -a
[root@localhost ~]# mount /dev/sdc /wt
[root@localhost ~]# ll /wt/
total 16
drwx------. 2 root root 16384 Nov 26 05:23 lost+found
[root@localhost ~]#
#########################################################################################################3
在target服务端，再添加几个存储客户端，并实现同步数据。
1、在target服务端
[root@localhost ~]# vim /etc/tgt/targets.conf
[root@localhost ~]# tail -6 /etc/tgt/targets.conf
<target iqn.2015-11.com.sohu:san1>
vendor_id sohu
backing-store /dev/sdc
initiator-address 10.0.0.2
initiator-address 10.0.0.3
</target>
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# /etc/init.d/tgtd restart
Stopping SCSI target daemon: initiators still connected [FAILED]
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
或
[root@localhost ~]# service tgtd restart
Stopping SCSI target daemon: [ OK ]
Starting SCSI target daemon: [ OK ]
[root@localhost ~]#
[root@localhost ~]#
2、再开2台客户端。
10.0.0.3
10.0.0.4
[root@localhost Desktop]#
[root@localhost Desktop]# rpm -vih /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm
warning: /media/CentOS_6.5_Final/Packages/iscsi-initiator-utils-6.2.0.873-10.el6.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [100%]
1:iscsi-initiator-utils ########################################### [100%]
[root@localhost Desktop]#
[root@localhost Desktop]# mkdir /wt
[root@localhost Desktop]#
[root@localhost Desktop]# iscsiadm -m discovery -t sendtargets -p 10.0.0.1:3260
Starting iscsid: [ OK ]
iscsiadm: No portals found
[root@localhost Desktop]#
root@localhost ~]# mount /dev/sdb /wt
[root@localhost ~]# ll /wt/
total 36
drwxr-xr-x. 2 root root 4096 Nov 26 09:52 22
drwxr-xr-x. 2 root root 4096 Nov 26 09:52 2222
drwxr-xr-x. 2 root root 4096 Nov 26 09:45 3
drwxr-xr-x. 2 root root 4096 Nov 26 09:49 33
drwxr-xr-x. 2 root root 4096 Nov 26 09:59 44444
-rw-r--r--. 1 root root 0 Nov 26 09:42 a
drwx------. 2 root root 16384 Nov 26 09:41 lost+found
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
总结，在10.0.0.2 10.0.0.3 10.0.0.4 上面分别挂载创建文件，如上，10.0.0.2创建22.2222.10.0.0.3创建3.33，依次来区分。然后，分别在各个系统上卸载后重新挂载，发现数据同步了。