ISCSI(Internet Small Computer System Interface) 是一种 SAN(Storage Area network) 的实现
环境:
OS: CentOS6.7
node1: 10.11.8.187 (target)
node2: 10.11.8.186 (initiator)
node3: 10.11.8.200 (initiator)
安装:
target(即服务端, 提供存储): scsi-target-utils
initiator(即使用端): iscsi-initiator-utils
target 端:
服务脚本: /etc/init.d/tgtd
管理命令: tgtadm
tgtadm模式化的命令
-m, –mode [target、logicalunit、account]
target –op [new、delete、show、update、bind、unbind]
logicalunit –op [new、delete]
account –op [new、delete、bind、unbind]
-L, –lld <driver>
-t, –tid
-l, –lun
-b, –backing-store <path>
-I, –initiator-address <address>
-T, –targetname <targetname>
initiator 端:
服务脚本: /etc/init.d/iscsid
管理命令: iscsiadm
iscsiadm模式化的命令
-m {discovery|node|session|iface}
discovery: 发现某服务器是否有target输出，以及输出了哪些target；
node: 管理跟某target的关联关系；
session: 会话管理
iface: 接口管理
iscsiadm -m discovery [ -d debug_level ] [ -P printlevel ] [ -I iface -t type -p ip:port [ -l ] ]
-d: 0-8
-I: Network interface
-t type: SendTargets(st), SLP, and iSNS
-p: IP:port
对所有的操作
iscsiadm -m node [ -d debug_level ] [ -L all,manual,automatic ] | [ -U all,manual,automatic ]
对单个的操作
iscsiadm -m node [ -d debug_level ] [ [ -T targetname -p ip:port -I ifaceN ] [ -l | -u ] ] [ [ -o operation ] [ -n name ] [ -v value ] ]
iscsi-initiator-utils:
不支持discovery认证；
如果使用基于用户的认证，必须首先开放基于IP的认证；
node1 配置 target 服务:
1.创建一个控制器
[root@node1 ~]# tgtadm --lld iscsi --mode target --op new --targetname iqn.2016.com.shiina:storage.disk1 --tid 1
[root@node1 ~]# tgtadm --lld iscsi --mode target --op show
Target 1: iqn.2016.com.shiina:storage.disk1
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:
Account information:
ACL information:2.创建一块存储设备
[root@node1 ~]# tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 --backing-store /dev/sdb
[root@node1 ~]# tgtadm --lld iscsi --mode target --op show
Target 1: iqn.2016.com.shiina:storage.disk1
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: 8590 MB, Block size: 512
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: rdwr
Backing store path: /dev/sdb
Backing store flags:
Account information:
ACL information:3.添加访问控制
[root@node1 ~]# tgtadm --lld iscsi --mode target --op bind --tid 1 --initiator-address 10.11.0.0/16
[root@node1 ~]# tgtadm --lld iscsi --mode target --op show
Target 1: iqn.2016.com.shiina:storage.disk1
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: 8590 MB, Block size: 512
Online: Yes
Removable media: No
Prevent removal: No
Readonly: No
Backing store type: rdwr
Backing store path: /dev/sdb
Backing store flags:
Account information:
ACL information:
10.11.0.0/16tgtadm 所做的修改全都是在内核中保存的, 重启服务器后所有记录将会消失, 若想自动生效, 需要将配置写在 /etc/tgt/target.conf中, 以上的简单配置在文件中可以这样定义:
<target iqn.2016.com.shiina:storage.disk1>
backing-store /dev/sdb
initiator-address 10.11.0.0/16
</target>详细配置文件内有事例
node2 配置 initiator:
iscsi-iname 命令: 生成initiator-name
-p: 指定名前缀
1.生成InitiatorName
[root@node2 ~]# echo "InitiatorName=`iscsi-iname -p iqn.2016.com.shiina`" > /etc/iscsi/initiatorname.iscsi
[root@node2 ~]# cat /etc/iscsi/initiatorname.iscsi
InitiatorName=iqn.2016.com.shiina:60362cc811e42.搜索发现 target:
[root@node2 ~]# iscsiadm -m discovery -t sendtargets -p 10.11.8.187
10.11.8.187:3260,1 iqn.2016.com.shiina:storage.disk1
[root@node2 ~]# ll /var/lib/iscsi/send_targets/10.11.8.187,3260/
total 8
lrwxrwxrwx 1 root root 73 May 28 20:44 iqn.2016.com.shiina:storage.disk1,10.11.8.187,3260,1,default -> /var/lib/iscsi/nodes/iqn.2016.com.shiina:storage.disk1/10.11.8.187,3260,1
-rw------- 1 root root 554 May 28 20:44 st_config3.登录: 表示将远程主机target对应的lun关联到本机
[root@node2 ~]# iscsiadm -m node -T iqn.2016.com.shiina:storage.disk1 -p 10.11.8.187 -l
Logging in to [iface: default, target: iqn.2016.com.shiina:storage.disk1, portal: 10.11.8.187,3260] (multiple)
Login to [iface: default, target: iqn.2016.com.shiina:storage.disk1, portal: 10.11.8.187,3260] successful.
[root@node2 ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0000bfe1
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 157 1048576 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 157 2611 19717120 8e Linux LVM
Disk /dev/mapper/vol0-root: 5242 MB, 5242880000 bytes
255 heads, 63 sectors/track, 637 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/vol0-usr: 14.9 GB, 14944305152 bytes
255 heads, 63 sectors/track, 1816 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xfa870733
Device Boot Start End Blocks Id System
/dev/sdb1 1 1044 8385898+ 83 Linux
PS: sdb1 是 node1 上一个尚未格式化的分区4.格式化并写入数据
[root@node2 ~]# mke2fs -j /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
524288 inodes, 2096474 blocks
104823 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2147483648
64 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 22 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@node2 ~]# mount /dev/sdb1 /mnt
[root@node2 ~]# cp /etc/fstab /mnt/node3 配置initiator并登录:
[root@node3 ~]# iscsiadm -m discovery -t sendtargets -p 10.11.8.187
Starting iscsid: [ OK ]
10.11.8.187:3260,1 iqn.2016.com.shiina:storage.disk1
[root@node3 ~]# iscsiadm -m node -T iqn.2016.com.shiina:storage.disk1 -p 10.11.8.187 -l
Logging in to [iface: default, target: iqn.2016.com.shiina:storage.disk1, portal: 10.11.8.187,3260] (multiple)
Login to [iface: default, target: iqn.2016.com.shiina:storage.disk1, portal: 10.11.8.187,3260] successful.
[root@node3 ~]# mount /dev/sdb1 /mnt
[root@node3 ~]# ls /mnt/
fstab lost+found # 此时fatab文件存在在 node2 和 node3 同时挂载的情况下,在 node3 写入数据:
[root@node3 ~]# cp /etc/inittab /mnt/
[root@node3 ~]# ls /mnt/
fstab inittab lost+found
[root@node2 ~]# ls /mnt/
fstab lost+found此时查看 node2 却发现并无 inittab 文件, 说明 node3 的数据写入依然停留在内存中, 尚未同步到硬盘
此种情况下容易造成文件系统崩溃, 因此只允许一台设备挂载, 若希望同时挂载, 则需安装集群文件系统
