ceph luminous 提供iscsi服务

admin

开始安装之前必须要满足以下条件：
! x: I6 P" F6 r6 L* T正在运行的Ceph Luminous版本集群或更高版本的存储群集；（本文我们采用的是M版本）
# k6 z) Q7 i/ uRHEL/CentOS 7.5或者Linux kernel v4.16或更新；
同时拥有以下几个包：
targetcli-2.1.fb47 or      newer package
python-rtslib-2.1.fb64 or      newer package
$ l% l+ }# v2 ?7 z2 b: E! btcmu-runner-1.3.0 or      newer package
# H. ~3 G/ H! Y* \! e0 Z8 [% a  t* pceph-iscsi-config-2.4 or      newer package
3 e. I' q. N$ i* iceph-iscsi-cli-2.5 or      newer package
9 k* s- n& G, c% w注意：我们本次安装ISCSI GW是在OSD 节点上安装
* H1 S$ z9 M5 H* I# R% ?, b" s/ L由于很多童鞋可能获取不到rpm包，所以我这里整理了一下所需要的rpm并且分享了出来，以下是链接
5 z( i  z$ X6 F$ o: i& g链接: https://pan.baidu.com/s/1piNymp6oWLNHvXKaxBszLg 密码: 4vag
9 E" r) E" r: k: `; ~安装部分就不说了只要把rpm包下载到本地，安装很简单，下面来说下配置部分：
首先创建一个iscsi gw的配置文件
# touch /etc/ceph/iscsi-gateway.cfg
里面内容如下：
! n5 B  f5 X# Z3 n+ g[config]
# b" J- }5 P( m. T9 s# Name of the Ceph storage cluster. A suitable Ceph configuration file allowing
# access to the Ceph storage cluster from the gateway node is required, if not
# colocated on an OSD node.
; S( I4 ?$ M# \$ D' C  J9 }cluster_name = ceph
4 c0 a6 x3 ?  B. b- t1 J" d5 n5 }
( H! w6 p( t" f  `  j# Y/ m# Place a copy of the ceph cluster's admin keyring in the gateway's /etc/ceph
# drectory and reference the filename here
6 y) @/ S- b, u" u0 xgateway_keyring = ceph.client.admin.keyring


# API settings.
( g  \" _# l; g1 w7 D# The API supports a number of options that allow you to tailor it to your
# local environment. If you want to run the API under https, you will need to
$ |, X, i2 u' S# y+ z# create cert/key files that are compatible for each iSCSI gateway node, that is
# not locked to a specific node. SSL cert and key files *must* be called
% s3 ~5 @" b; v0 N2 V- N# 'iscsi-gateway.crt' and 'iscsi-gateway.key' and placed in the '/etc/ceph/' directory
# on *each* gateway node. With the SSL files in place, you can use 'api_secure = true'
2 k/ I# j* F, r0 h* j, D, o# z& A; [# to switch to https mode.

2 z# y' v- C. {0 f. S# To support the API, the bear minimum settings are:
api_secure = false

8 i# G7 q( `1 [% O# Additional API configuration options are as follows, defaults shown.
# api_user = admin
/ f/ V( ~3 |& ^! i( ]; T, n8 }* e# api_password = admin
# api_port = 5001
. }$ l. x* H5 |2 z; R; C# trusted_ip_list = 192.168.0.10,192.168.0.11
注意：需要修改的地方就行把trusted_ip_list替换成自己实际场景的节点ip
0 {" l" k; Y' \/ v) R& i完事之后重启iscsi服务
! q# k7 @: Z. a4 ^/ Z+ \  R* K# systemctl daemon-reload
; e8 o8 }; L( D4 e" B- }6 ]# systemctl enable rbd-target-api
# systemctl start rbd-target-api
OK到此为止，iscsi gw已经安装配置完成，下面开始创建iscsi target
! p0 H& [" l! I# p# o
$ B) v* a1 }2 }# s1.执行gwcli命令进入iscsi

2.创建iscsi target
5 F/ ]# Y5 Z/ d- c> /> cd /iscsi-target
> /iscsi-target>  create iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw
8 T/ ^9 A& o' C0 f3 X
# z  W0 p, W% F3 \7 F, B3 V3.创建iSCSI网关。以下使用的IP是用于iSCSI数据传输的IP,它们可以与trusted_ip_list中列出的用于管理操作的IP相同，也可以不同，看有没有做多网卡分离
> /iscsi-target> cd iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw/gateways
> /iscsi-target...-igw/gateways>  create ceph-gw-1 10.172.19.21 skipchecks=true
> /iscsi-target...-igw/gateways>  create ceph-gw-2 10.172.19.22 skipchecks=true
7 T: A9 q1 c- o! t# ^' \  d
/ g7 y7 Q7 g4 J) k4.创建一个rbd设备disk_1
6 L% q' T/ Z4 A* w  [) r% o> /iscsi-target...-igw/gateways> cd /disks
! T7 }0 o2 O! v5 q5 R( l' L7 X4 P> /disks> create pool=rbd image=disk_1 size=90G
  J) N( \4 z+ d  H7 y6 I
5.创建iqn
> /disks> cd /iscsi-target/iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw/hosts
" @- L% K* ]& \> /iscsi-target...eph-igw/hosts>  create iqn.1994-05.com.redhat:rh7-client
( O4 ]4 J6 y1 M0 R
# z/ I8 j. y8 k$ q! W3 h6.创建chap的用户名密码，并且chap必须设置，否则服务端是禁止连接的
/ j6 }% j5 ~, Q4 T$ C9 P( X> /iscsi-target...at:rh7-client>  auth chap=myiscsiusername/myiscsipassword
' i& F  \. l- c9 D
# ?1 m# y2 F( l" I% n1 W7.增加磁盘到客户端
  |7 a. F8 g, ^7 i> /iscsi-target...at:rh7-client> disk add rbd.disk_1

4 {/ z* S+ e' G3 W: i7 tOK，到这里就配置完成了，我们看下最终是什么样的
* z3 @/ d5 K2 r' y3 e; a+ {' u4 ]" E* Iiscsi.png

/ E1 R" T/ e# {- S8 |3 s安装配置完之后就可以挂载使用了，一般也就是windows/Linux，我们先说下Linux下挂载方式
4 n4 o2 ^$ o( a1 z
1.安装iscsi工具
! `1 U- x/ t, c$ I/ j, h  R# yum install iscsi-initiator-utils
, t7 }' g3 o- e* [2 d& a# yum install device-mapper-multipath

' e" ^: l7 v% V9 l2.配置多路径
# mpathconf --enable --with_multipathd y
$ |6 d% h- }, p$ n/ s# ~devices {
        device {
                vendor                 "LIO-ORG"
. z6 R8 J# V4 m  Q, \7 u) K                hardware_handler       "1 alua"
* |! ]$ b" d3 a) j* y. T                path_grouping_policy   "failover"
5 w4 E5 P& m$ @- ]                path_selector          "queue-length 0"
                failback               60
1 @( ^) d) p; h9 ^+ A" J; i                path_checker           tur
                prio                   alua
                prio_args              exclusive_pref_bit
                fast_io_fail_tmo       25
                no_path_retry          queue
        }
}

; `5 ]+ o8 \" ?2 I3.重启服务
1 V, ^, W; B+ [$ o" O/ p* [# systemctl reload multipathd

4.配置chap认证
修改配置客户端的名称为之前设置的名称
# vi /etc/iscsi/initiatorname.iscsi
InitiatorName= iqn.1994-05.com.redhat:rh7-client
& Y+ F7 J5 E6 q修改chap认证配置文件
# vi /etc/iscsi/iscsid.conf
node.session.auth.authmethod = CHAP
. J7 k. A! a- a# o% k' r node.session.auth.username = myiscsiusername
0 b# s- S2 e# q* t% Y node.session.auth.password = myiscsipassword

5.查询iscsi target
# iscsiadm -m discovery -t -st 10.172.19.21
" d$ |3 c2 F# M6 K9 S2 V
6.连接target
# iscsiadm -m node -T iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw -l
9 ?# K  x3 h4 O5 A0 o# multipath –ll
/ g0 C. j2 X3 s& g% C

admin

[root@ceph01 ~]# vi /etc/yum.repos.d/CentOS-Base.repo

5 s1 w$ U0 J  a5 F[Storage]
1 a; G# U. H5 j$ g& aname=CentOS-$releasever - Storage
) a0 I$ k! X4 E* C. N+ _) o$ o9 nbaseurl=https://mirrors.huaweicloud.com/centos/7.7.1908/storage/x86_64/ceph-nautilus/
6 k' e$ [( e7 egpgcheck=0
enabled=1
8 a% I5 @3 U+ i
1 v, r; c% H  i+ h. z, u[Gluster]
name=CentOS-$releasever - Storage
baseurl=https://mirrors.huaweicloud.com/centos/7.7.1908/storage/x86_64/gluster-5/
/ o% d% a; e5 x; _4 B- M7 s+ D7 qgpgcheck=0
) m* g# w9 D! |' ]enabled=1
: j+ d! K, H* D" ~
[ceph-iscsi]
1 c5 b$ Y5 ]6 C6 Qname=CentOS-$releasever - Storage
baseurl=https://mirrors.huaweicloud.com/ceph/ceph-iscsi/3/rpm/el7/noarch/
gpgcheck=0
enabled=1

[epel]
8 b+ M3 o+ n0 N3 b+ Hname=CentOS-$releasever - Storage
baseurl=https://mirrors.huaweicloud.com/epel/7Server/x86_64/
gpgcheck=0
: k2 s: U6 g" X% eenabled=1
2 }( n: w5 g7 P% p8 Q4 X$ }3 a

admin

直接yum install试试可以发现，只有targetcli和python-rtslib能装上，而且版本都比官网说的要低，好吧，麻烦来了。
* j! p. R- q' i1 W8 l6 W& ^8 s
经过一段几个小时*的搜索……从下面链接中找到了rpm包：
! p/ f0 u- H- i
Build new RPM for 3.0
, p- }' }; `! z- `Missing ceph-iscsi-cli package
新建repo文件：
! h% c# b7 M; `6 J: q
sudo vim /etc/yum.repo.d/iscsi.repo
cat /etc/yum.repo.d/iscsi.repo
# {4 u) s1 \# [- C# I
  \3 E$ T* W$ H( q[ceph-iscsi]
7 `: O1 W+ ?. i/ e' M5 H' tname=Ceph-iscsi
2 u7 D8 }: C: Mbaseurl=https://4.chacra.ceph.com/r/ceph-iscsi/master/88f3f67981c7da15448f140f711a1a8413d450b0/centos/7/flavors/default/noarch/
9 o. D: f' _' }# w$ x5 bpriority=1
gpgcheck=0

[tcmu-runner]
) i8 ?0 i5 a+ U$ _9 a$ gname=tcmu-runner
baseurl=https://3.chacra.ceph.com/r/tcmu-runner/master/eef511565078fb4e2ed52caaff16e6c7e75ed6c3/centos/7/flavors/default/x86_64/
priority=1
- j4 l, t( q, sgpgcheck=0

1 R# J9 z6 n2 t5 G: x[python-rtslib]
name=python-rtslib
- v) P4 t$ m9 F( Y+ }8 tbaseurl=https://2.chacra.ceph.com/r/python-rtslib/master/67eb1605c697b6307d8083b2962f5170db13d306/centos/7/flavors/default/noarch/
priority=1
4 `9 A6 K) `/ a5 ?- h# ]1 d6 S  xgpgcheck=0
这里我使用的是本地源，将上面的包下载到本地源：
; }; g% P# y" h: `- a8 a3 ^
sudo yum install --downloadonly --downloaddir=yum/ceph-iscsi/ targetcli python-rtslib tcmu-runner ceph-iscsi
+ Q, p2 O- q* |; |3 P$ k6 U createrepo -p -d -o yum/ yum/
# v& d- ~2 U  g. v' v+ H* L5 ?; R6 q注意到这里没有包含targetcli的repo，因为没有找到，使用yum基础的Base源或者是Ceph源可以安装targetcli-2.1.fb46-7.el7.noarch.rpm， 虽然官网需要的是targetcli-2.1.fb47 or newer package，但在后续使用中发现没有影响，所以这里就不用管targetcli了。

那么这里下载下来的就是：
4 K1 Y' s! ]) o' N9 i3 E
targetcli-2.1.fb46-7.el7.noarch.rpm
python-rtslib-2.1.fb68-1.noarch.rpm
tcmu-runner-1.4.0-0.1.51.geef5115.el7.x86_64.rpm
ceph-iscsi-3.2-8.g88f3f67.el7.noarch.rpm
6 U. ?" E* I7 {ceph-iscsi网关初始配置
如果使用的不是集群内的节点作为ceph-iscsi网关，那就需要进行一些初始的配置。
; }# `8 }7 I  g% i8 C  L/ u
安装ceph。
$ p* b8 Y8 o3 s& _3 p2 v) U从集群中的一台机器上拷贝/etc/ceph/ceph.conf到本机的/etc/ceph/ceph.conf。
从集群中的一台机器上拷贝/etc/ceph/ceph.client.admin.keyring到本机的/etc/ceph/ceph.client.admin.keyring。
. q& D4 p; N  ~3 C5 f* q当然第2和3步可以直接在deploy节点使用ceph-deploy admin {node-gateway}，{node-gateway}就表示网关节点的名字。
5 E' {% d# u3 C! ?0 ]( b$ v' _
& e; x( d" k, e/ n* Y7 `可见这里就是为了将ceph-iscsi网关节点变成一个admin节点。

) O: t8 ]3 ^6 [! H" F/ m这时在网关节点上应该可以执行相关命令操作ceph集群，例如sudo ceph -s查询当前集群的状态。

安装配置iscsi
这里官网建议先切换到root用户，方便一点：
' L+ ]/ k3 z- I( [+ w4 k
su root
0 `1 E) M2 G2 n/ t; h6 _' q: g在两个网关节点上都安装iscsi（注意到上面已经将相关包下载到了本地源，所以可以直接yum安装）：

0 ^2 T3 i6 }) E. f2 y9 n- K2 } yum install -y ceph-iscsi
服务启动：
4 y+ W6 L! O2 g. N0 t2 F/ l) a
' w# x8 Q/ d. |4 @) h* {先创建rbd pool，如果没有的话。

ceph osd lspools

# g( b- A" S9 G% ^- S* b3 V9 X1 cephfs_data
2 cephfs_metadata
+ W+ w: s4 G$ [  Q5 w
ceph osd pool create rbd 128
/ s  n9 |0 P8 e& s0 v/ J
pool 'rbd' created
2 o  D6 d* E$ _创建并修改/etc/ceph/iscsi-gateway.cfg文件：

vim /etc/ceph/iscsi-gateway.cfg
4 c9 ~8 \" G. z/ |8 L# I cat /etc/ceph/iscsi-gateway.cfg
/ h! Y; y& a/ f) Y* A( B
7 f8 {/ t0 O6 T+ U' r" H; ?) t- V/ R, t[config]
8 A) @5 v6 I$ d2 ?5 w' M Name of the Ceph storage cluster. A suitable Ceph configuration file allowing
access to the Ceph storage cluster from the gateway node is required, if not
colocated on an OSD node.
9 @7 X, I% {$ Ucluster_name = ceph
9 c# F3 M' k6 e! D
; p/ v6 z, `, q/ O3 e Place a copy of the ceph cluster's admin keyring in the gateway's /etc/ceph
' z/ [  Y9 @! I3 I- y! [/ F drectory and reference the filename here
gateway_keyring = ceph.client.admin.keyring
, r# u( y' C0 U, A

API settings.
The API supports a number of options that allow you to tailor it to your
( q# I# r+ A( ?4 @6 f4 j local environment. If you want to run the API under https, you will need to
create cert/key files that are compatible for each iSCSI gateway node, that is
- X. H3 A# c6 u* a& u& r" @* a- x; S% ~ not locked to a specific node. SSL cert and key files *must* be called
'iscsi-gateway.crt' and 'iscsi-gateway.key' and placed in the '/etc/ceph/' directory
on *each* gateway node. With the SSL files in place, you can use 'api_secure = true'
) y3 w- b$ Z: ], E# X: n: N7 i to switch to https mode.
% G7 N& D6 f7 t
5 c& S: h6 ^3 M# y; h5 L$ v- [ To support the API, the bear minimum settings are:
% T. S3 f" [' [3 L8 `api_secure = false
+ y! ^& p+ U6 S' _
+ i( x/ l. I* X0 ?2 q: h# {4 h2 M9 ` Additional API configuration options are as follows, defaults shown.
api_user = admin
" V- m8 x5 }6 h api_password = admin
( L: ?" P1 T) b5 [+ j2 n  C api_port = 5001
trusted_ip_list = 192.168.90.234,192.168.90.235
上面trusted_ip_list填写的就是两台网关的ip（这里不讨论多网卡的情况）。
5 e9 L, C6 F8 }- _+ K  w; [0 b# s
在另外一台网关上复制这个文件：

* K1 v' n7 `$ z+ K, b% B4 O sudo scp cluster@node2:/etc/ceph/iscsi-gateway.cfg /etc/ceph/iscsi-gateway.cfg
7 u- k" @9 l9 O# f8 e  f在两台网关上都开启rbd-target-api服务：
& S9 P; T$ F5 P1 m
4 X4 _* r% p: e( x systemctl daemon-reload
+ S3 Y  [3 [* W: \  W: B systemctl enable rbd-target-api
systemctl start rbd-target-api
配置：（在其中一台网关配置就行）

gwcli
cd /iscsi-targets

1 ~+ z6 S! q8 d* m% h( q create iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw
( Y" ^7 e8 Q; Pok
$ Y) b) }1 H) q0 v5 X. `1 R
cd iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw/gateways
- O/ D6 X1 Y3 j$ o5 Q8 p1 R, w
7 Y3 N2 B5 G  Q0 D* m. l) H& ?/iscsi-target...-igw/gateways> create node2 192.168.90.234
; B0 A( H/ d2 U4 h+ W+ V& z/ i( AAdding gateway, sync'ing 0 disk(s) and 0 client(s)
ok

: w  }& N! u; G$ @# p/iscsi-target...-igw/gateways> create node3 192.168.90.235
Adding gateway, sync'ing 0 disk(s) and 0 client(s)
ok

/iscsi-target...-igw/gateways> cd /disks

& {- J9 c  r# [; T create pool=rbd image=disk_1 size=200G
ok

* T; L/ V! G! i cd /iscsi-targets/iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw/hosts
% i. y5 h3 `7 Z
1 R+ e2 Z! D9 f/iscsi-target...csi-igw/hosts> create iqn.1994-05.com.redhat:rh7-client
9 \* r3 s* ?; V+ Q* o8 `ok
) C( F, a. x+ @9 ]; e
3 [: K- Z' p$ ?* S" F/ `/iscsi-target...at:rh7-client> auth username=myiscsiusername password=myiscsipassword
6 P. u: R8 d5 zok
9 y, T4 n6 k9 h% X, _& s8 R
, c, {; A. i: Q2 I( _$ D" ?6 W/iscsi-target...at:rh7-client> disk add rbd/disk_1
, O! R1 P5 |# I1 mok
配置完成，可以看到我当前的目录结构：

ls
o- / ......................................................................... [...]
  o- cluster ......................................................... [Clusters: 1]
  | o- ceph .......................................................... [HEALTH_WARN]
  |   o- pools .......................................................... [Pools: 3]
5 c2 z. w. {, ?! V  |   | o- cephfs_data ... [(x3), Commit: 0.00Y/2028052096K (0%), Used: 2029431878b]
( Z; M' ~# h. D/ Y; ]  |   | o- cephfs_metadata .... [(x3), Commit: 0.00Y/2028052096K (0%), Used: 77834b]
  |   | o- rbd ................ [(x3), Commit: 200G/2028052096K (10%), Used: 15352b]
  |   o- topology ................................................ [OSDs: 6,MONs: 3]
+ R1 J! o; |9 p2 a5 l  o- disks ........................................................ [200G, Disks: 1]
, C1 s: ?$ V) P3 p# e1 N  g2 x  | o- rbd ............................................................ [rbd (200G)]
# ]2 w/ n- x. |4 _- \3 Y) F$ d  |   o- disk_1 ................................................ [rbd/disk_1 (200G)]
$ O4 O/ {+ `$ r0 m1 g5 I. q  o- iscsi-targets ............................... [DiscoveryAuth: None, Targets: 1]
# y! ^. r/ n' U6 n7 m2 O( Q$ W7 `; F    o- iqn.2003-01.com.redhat.iscsi-gw:iscsi-igw ..................... [Gateways: 2]
0 x+ ~& k1 R( G! g+ [      o- disks .......................................................... [Disks: 1]
# R7 b5 t; g" _      | o- rbd/disk_1 ............................................... [Owner: node3]
! z! [. c! o$ h1 H      o- gateways ............................................ [Up: 2/2, Portals: 2]
      | o- node2 ............................................. [192.168.90.234 (UP)]
4 W  k9 }5 w. `0 `      | o- node3 ............................................. [192.168.90.235 (UP)]
4 C! U1 H* _9 {! Y- L* Z      o- host-groups .................................................. [Groups : 0]
      o- hosts .............................................. [Hosts: 1: Auth: CHAP]
        o- iqn.1994-05.com.redhat:rh7-client .......... [Auth: CHAP, Disks: 1(200G)]
* S4 X1 T8 o1 m$ C$ q% p# r. Y          o- lun 0 ................................ [rbd/disk_1(200G), Owner: node3]
/ M! i3 `& E- y* k2 clinux客户端配置
在作为客户端的linux主机上。

3 u9 O$ R' W+ X+ n安装相关组件：
  N, R1 Q$ |. ~6 _% }9 K- M
sudo yum install -y iscsi-initiator-utils
sudo yum install -y device-mapper-multipath
6 P) e. D: w4 g( B( D开启multipathd服务并进行配置：
# y9 @0 H1 H( b4 P& }+ H1 ^4 Q
# t: {2 Z% L- ?! `1 w9 Z/ y sudo mpathconf --enable --with_multipathd y

; }1 a* b; Z5 S/ K+ @/ u5 v sudo vim /etc/multipath.conf
) q2 j: j! Z3 W4 X- z. G, W5 O9 Z sudo cat /etc/multipath.conf
! @' L2 x/ B( D6 O( @% {
devices {
: N( R% H  u1 {  i$ l        device {
" W/ c' s' |3 O6 C) f5 }' P9 G                vendor                 "LIO-ORG"
                hardware_handler       "1 alua"
                path_grouping_policy   "failover"
- F7 [' |( G8 e                path_selector          "queue-length 0"
                failback               60
                path_checker           tur
0 S% W+ Z' \' B& `$ f0 A                prio                   alua
/ Z) O  t( B' L6 D0 X- j                prio_args              exclusive_pref_bit
                fast_io_fail_tmo       25
                no_path_retry          queue
* Z3 D# J; ?: p1 T) Q4 f        }
}
修改客户端名称：

sudo vim /etc/iscsi/initiatorname.iscsi
sudo cat /etc/iscsi/initiatorname.iscsi

' p3 B2 R4 J$ e9 n  uInitiatorName=iqn.1994-05.com.redhat:rh7-client
; N+ H/ {$ \- n修改chap认证配置文件：

' k& e6 m' X) a" A0 v sudo vim /etc/iscsi/iscsid.conf
2 D& d; r* }( z1 B& p2 Z" \! b sudo cat /etc/iscsi/iscsid.conf

5 M' }' B8 q$ V...
( o+ `, h: g4 u *************
CHAP Settings
- L4 ^: b, @8 W  {2 T *************
1 i  }) ~. w& y% F$ X1 }" N
  M. ^9 Y. C* _ To enable CHAP authentication set node.session.auth.authmethod
8 ]2 N  ]% Z$ H2 m5 q" A to CHAP. The default is None.
node.session.auth.authmethod = CHAP

( r+ v  g% c- V To set a CHAP username and password for initiator
* O' P" i/ f6 n2 m0 ~/ c: c authentication by the target(s), uncomment the following lines:
node.session.auth.username = myiscsiusername
! ^! B4 Y4 {8 |2 t5 A. O( X; mnode.session.auth.password = myiscsipassword
1 _. j9 x# l! g3 A6 [...
' F9 v2 v  M/ Q4 m; i  r
5 X4 v3 ?6 |* F发现target：

sudo iscsiadm -m discovery -t st -p 192.168.90.234

192.168.90.234:3260,1 iqn.2003-01.org.linux-iscsi.rheln1
192.168.90.235:3260,2 iqn.2003-01.org.linux-iscsi.rheln1
登入target：

2 t! x( i0 R0 \: q: d& F, q3 g2 e sudo iscsiadm -m node -T iqn.2003-01.org.linux-iscsi.rheln1 -l
查看是否成功：
: {" z* l6 v3 q& @2 w( v6 R
sudo multipath -ll
5 x. ]1 u5 J, \; a5 S4 smpatha (360014050fedd563975249adb2e84e978) dm-2 LIO-ORG ,TCMU device     
5 ~' V! a5 Y7 i  v8 zsize=200G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
) w# H6 A* C: N3 R. N) ~|-+- policy='queue-length 0' prio=50 status=active
1 ^& u9 T% R: H% O1 W7 \! c& Z| `- 3:0:0:0 sdc 8:32 active ready running
`-+- policy='queue-length 0' prio=10 status=enabled
  `- 2:0:0:0 sdb 8:16 active ready running
在fdisk中就可以直接看到这个“硬盘”：
( m0 `! k, {; P: H
sudo fdisk -l
* b2 g  u2 d; t4 A4 e
- }7 k4 u1 u  x1 {0 |& Z...
+ U0 t4 B- n& YDisk /dev/mapper/mpatha: 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 / 524288 bytes