RHCE7認證學習筆記34——配置ISCSI

一、儲存裝置型別

• DSA：直接區域儲存
• NAS:網路區域儲存
• SAN：儲存區域網路，塊級別共享

二、配置iscsi伺服器端

這裡舉例子說明，假如伺服器有2個分割槽/dev/sdb7,/dev/sdb8要共享出去:    
    /dev/sdb7      1230848      1640447    200M  Linux filesyste 
    /dev/sdb8      1640448      2459647    400M  Linux filesyste

安裝target包：
[root@linuxidc ~]# yum install target\* -y

啟動target服務
[root@linuxidc ~]# systemctl start target 
    
配置步驟：

1、準備要共享的塊；

使用targetcli命令進入target配置介面：
 [root@linuxidc ~]# targetcli

/> pwd
/ 
/> ls
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]

進入backstores/block目錄建立要共享的塊，建立block1和block2：
        
/> cd backstores/ 
/backstores> ls
o- backstores ................................................................................................................ [...] 
  o- block .................................................................................................... [Storage Objects: 0] 
  o- fileio ................................................................................................... [Storage Objects: 0] 
  o- pscsi .................................................................................................... [Storage Objects: 0] 
  o- ramdisk .................................................................................................. [Storage Objects: 0] 
        
/backstores/block> create block1 dev=/dev/sdb7
Created block storage object block1 using /dev/sdb7. 
/backstores/block> create block2 dev=/dev/sdb8
Created block storage object block2 using /dev/sdb8.

/backstores/block> ls
o- block ...................................................................................................... [Storage Objects: 2] 
  o- block1 .......................................................................... [/dev/sdb7 (200.0MiB) write-thru deactivated] 
  o- block2 .......................................................................... [/dev/sdb8 (400.0MiB) write-thru deactivated]

exit退出儲存targetcli，並重新進入：
/backstores/block> exit
Global pref auto_save_on_exit=true
Last 10 configs saved in /etc/target/backup. 
Configuration saved to /etc/target/saveconfig.json 
[root@linuxidc ~]# targetcli

2、建立一個target;

target標準名字格式：

年  月  域名倒寫 名字

iqn.2015-02.com.sg:disk1

進入iscsi目錄，建立target:

/iscsi> create iqn.2015-02.com.sg:disk1 
                    
/iscsi> ls
o- iscsi .............................................................................................................. [Targets: 1] 
  o- iqn.2015-02.com.sg:disk1 ............................................................................................ [TPGs: 1]

3、在target上面建立一個lun；

進入/iscsi/iqn.2015-02.com.sg:disk1/tpg1目錄：      
 /iscsi/iqn.20...sg:disk1/tpg1> ls
o- tpg1 ..................................................................................................... [no-gen-acls, no-auth] 
  o- acls ................................................................................................................ [ACLs: 0] 
  o- luns ................................................................................................................ [LUNs: 0] 
  o- portals .......................................................................................................... [Portals: 0]

acls目錄建立共享密碼：                    
 /iscsi/iqn.20...sg:disk1/tpg1> acls/ create iqn.2015-02.com.sg:diskpasswd

建立lun:        
/iscsi/iqn.20...sg:disk1/tpg1> luns/ create /backstores/block/block1
Created LUN 0. 
Created LUN 0->0 mapping in node ACL iqn.2015-02.com.sg:diskpasswd 
/iscsi/iqn.20...sg:disk1/tpg1> luns/ create /backstores/block/block2
Created LUN 1. 
Created LUN 1->1 mapping in node ACL iqn.2015-02.com.sg:diskpasswd

 o- luns .......................................................................................................... [LUNs: 2] 
  |    | o- lun0 ....................................................................................... [block/block1 (/dev/sdb7)] 
  |    | o- lun1 ....................................................................................... [block/block2 (/dev/sdb8)]

portal建立共享埠和地址：
/iscsi/iqn.20...sg:disk1/tpg1> portals/ create 10.35.89.32 
Using default IP port 3260 
Created network portal 10.35.89.32:3260.

exit退出並儲存：

Configuration saved to /etc/target/saveconfig.json

配置檔案儲存在：/etc/target/saveconfig.json，可以直接修改配置檔案

三、客戶端配置iscsi連線

安裝target包：  
[root@client ~]# yum install target\* -y

檢視fuw伺服器端共享的內容：
[root@client ~]# iscsiadm -m discovery -t st -p 10.35.89.32 
10.35.89.32:3260,1 iqn.2015-02.com.sg:disk1

編輯/etc/iscsi/initiatorname.iscsi檔案，配置伺服器端共享的名字和密碼：
InitiatorName=iqn.2015-02.com.sg:diskpasswd

重啟iscscid服務：

[root@client ~]# systemctl restart iscsid.service

掛載伺服器端共享的內容：

[root@client ~]# iscsiadm -m node -T iqn.2015-02.com.sg:disk1 -p 10.35.89.32 -l

掛載成功後，使用fdisk命令即可檢視到新增加的兩塊磁碟：

斷開掛載的連線：
[root@client ~]# iscsiadm -m node -T iqn.2015-02.com.sg:disk1 -p 10.35.89.32 -u

使用fdisk命令劃分共享的磁碟，格式化，並掛載資料夾，編輯fstab檔案設定開機自動掛載：
 [root@client ~]# fdisk /dev/sdb

Device Boot      Start        End      Blocks  Id  System 
/dev/sdb1            8192      114687      53248  83  Linux

[root@client ~]# mkfs.xfs /dev/sdb1

[root@client /]# mount /dev/sdb1 /aa

編輯fstab檔案時候，將default換成_netdev引數：

/dev/sdb1      /aa    xfs    _netdev 0 0