iscsi的结构和san的结构
iSCSI 通信端
- 发起 I/O 请求的启动设备(Initiator)
- 响应请求并执行实际 I/O 操作的目标设备(Target)
iSCSI工作过程
- target端导出共享设备
- initiator端发现设备
- initiator端导入设备
- initiator端分区、格式化、挂接设备
iSCSI实现套件
服务端（target）：scsi-target-utils软件包
客户端（initiator）：iscsi-initiator-utils软件包
部署过程：
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| yum insitall scsi-target-utils
yum insitall iscsi-initiator-utils
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服务器端导出共享设备： 配置文件如下
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| [root@rhel6 ~]# grep -v '#\|^$' /etc/tgt/targets.conf
default-driver iscsi
<target iqn.2015-10.com.example-f30:vdb1-1g>
backing-store /dev/vdb1
</target>
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启动tgtd服务
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| [root@rhel6 ~]# /etc/init.d/tgtd start
Starting SCSI target daemon: [ OK ]
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查看客户端本地有无/dev/sda设备
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| [root@rhel6 ~]# ll /dev/sda
ls: cannot access /dev/sda: No such file or directory
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搜索target端的共享设备
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| [root@rhel6 ~]# iscsiadm -m discovery -t st -p 172.25.30.10
172.25.30.10:3260,1 iqn.2015-10.com.example-f30:vdb1-1g
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导入target端的共享设备
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| [root@rhel6 ~]# iscsiadm -m node -l
Logging in to [iface: default, target: iqn.2015-10.com.example-f30:vdb1-1g, portal: 172.25.30.10,3260] (multiple)
Login to [iface: default, target: iqn.2015-10.com.example-f30:vdb1-1g, portal: 172.25.30.10,3260] successful.
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查看本地/dev/sda设备
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| [root@rhel6 ~]# ll /dev/sda
brw-rw----. 1 root disk 8, 0 Jan 14 14:51 /dev/sda
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卸载导入的设备
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| [root@rhel6 nodes]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Jan 14 14:53 /dev/sda
brw-rw----. 1 root disk 8, 16 Jan 14 15:35 /dev/sdb
brw-rw----. 1 root disk 8, 17 Jan 14 15:35 /dev/sdb1
[root@rhel6 nodes]# iscsiadm -m node -T iqn.2016-01-14.com.example.node4-f24:vdb1-1G -u
Logging out of session [sid: 2, target: iqn.2016-01-14.com.example.node4-f24:vdb1-1G, portal: 172.25.24.13,3260]
Logout of [sid: 2, target: iqn.2016-01-14.com.example.node4-f24:vdb1-1G, portal: 172.25.24.13,3260] successful.
[root@rhel6 nodes]# ll /dev/sd*
brw-rw----. 1 root disk 8, 0 Jan 14 14:53 /dev/sda
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配置iSCSI的acl和验证
在target主配置文件中添加如下两行
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| [root@rhel6 ~]# grep -v '#\|^$' /etc/tgt/targets.conf
default-driver iscsi
<target iqn.2015-10.com.example-f30:vdb1-1g>
backing-store /dev/vdb1
</target>
<target iqn.2015-10.com.example-f30:vdb2-2g>
backing-store /dev/vdb2
initiator-address 172.25.30.0/24
incominguser xiemx uplooking
</target>
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重新加载配置文件
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| /etc/init.d/tgtd reload
/etc/init.d/tgtd force-reload
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查看配置导出的设备信息
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| [root@rhel6 ~]# tgtadm --lld iscsi --mode target --op show
Target 1: iqn.2015-10.com.example-f30:vdb1-1g
System information:
Driver: iscsi
State: ready
I_T nexus information:
LUN information:
LUN: 0
Type: controller
SCSI ID: IET 00010000
SCSI SN: beaf10
Size: 0 MB, Block size: 1
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: null
Backing store path: None
Backing store flags:
LUN: 1
Type: disk
SCSI ID: IET 00010001
SCSI SN: beaf11
Size: 1074 MB, Block size: 512
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: rdwr
Backing store path: /dev/vdb1
Backing store flags:
Account information:
ACL information:
ALL
Target 2: iqn.2015-10.com.example-f30:vdb2-2g
System information:
Driver: iscsi
State: ready
I_T nexus information:
LUN information:
LUN: 0
Type: controller
SCSI ID: IET 00020000
SCSI SN: beaf20
Size: 0 MB, Block size: 1
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: null
Backing store path: None
Backing store flags:
LUN: 1
Type: disk
SCSI ID: IET 00020001
SCSI SN: beaf21
Size: 2148 MB, Block size: 512
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: rdwr
Backing store path: /dev/vdb2
Backing store flags:
Account information:
xiemx
ACL information:
172.25.30.0/24
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initiator端开启CHAP验证并配置用户密码
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| [root@rhel6 ~]grep -v '^#\|^$' /etc/iscsi/iscsid.conf
iscsid.startup = /etc/rc.d/init.d/iscsid force-start
node.startup = automatic
node.leading_login = No
node.session.auth.authmethod = CHAP
node.session.auth.username = xiemx
node.session.auth.password = uplooking
node.session.timeo.replacement_timeout = 120
node.conn[0].timeo.login_timeout = 15
node.conn[0].timeo.logout_timeout = 15
node.conn[0].timeo.noop_out_interval = 5
node.conn[0].timeo.noop_out_timeout = 5
node.session.err_timeo.abort_timeout = 15
node.session.err_timeo.lu_reset_timeout = 30
node.session.err_timeo.tgt_reset_timeout = 30
node.session.initial_login_retry_max = 8
node.session.cmds_max = 128
node.session.queue_depth = 32
node.session.xmit_thread_priority = -20
node.session.iscsi.InitialR2T = No
node.session.iscsi.ImmediateData = Yes
node.session.iscsi.FirstBurstLength = 262144
node.session.iscsi.MaxBurstLength = 16776192
node.conn[0].iscsi.MaxRecvDataSegmentLength = 262144
node.conn[0].iscsi.MaxXmitDataSegmentLength = 0
discovery.sendtargets.iscsi.MaxRecvDataSegmentLength = 32768
node.conn[0].iscsi.HeaderDigest = None
node.session.nr_sessions = 1
node.session.iscsi.FastAbort = Yes
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initiator重新发现并导入共享设备
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| [root@rhel6 nodes]# iscsiadm -m discovery -t st -p 172.25.30.10
172.25.30.10:3260,1 iqn.2015-10.com.example-f30:vdb1-1g
172.25.30.10:3260,1 iqn.2015-10.com.example-f30:vdb2-2g
[root@rhel6 nodes]# iscsiadm -m node -T iqn.2015-10.com.example-f30:vdb1-1g -l
Logging in to [iface: default, target: iqn.2015-10.com.example-f30:vdb1-1g, portal: 172.25.30.10,3260] (multiple)
Login to [iface: default, target: iqn.2015-10.com.example-f30:vdb1-1g, portal: 172.25.30.10,3260] successful.
[root@rhel6 nodes]# iscsiadm -m node -T iqn.2015-10.com.example-f30:vdb2-2g -l
Logging in to [iface: default, target: iqn.2015-10.com.example-f30:vdb2-2g, portal: 172.25.30.10,3260] (multiple)
Login to [iface: default, target: iqn.2015-10.com.example-f30:vdb2-2g, portal: 172.25.30.10,3260] successful.
[root@rhel6 nodes]# ll /dev/sd*
brw-rw----. 1 root disk 8, 16 Jan 14 16:04 /dev/sdb
brw-rw----. 1 root disk 8, 32 Jan 14 16:04 /dev/sdc
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