iSCSI网关集成了Ceph存储和iSCSI标准，以提供一个高可用性(HA) iSCSI目标，该目标将RADOS块设备(RBD)映像导出为SCSI磁盘。iSCSI协议允许客户机 (initiator) 通过TCP/IP网络向SCSI存储设备( targets )发送SCSI命令。这允许异构客户机访问Ceph存储集群。
每个iSCSI网关运行Linux IO目标内核子系统(LIO)，以提供iSCSI协议支持。LIO利用用户空间通过( TCMU ) 与Ceph的librbd库交互，并向iSCSI客户机暴露RBD镜像。使用Ceph的iSCSI网关，可以有效地运行一个完全集成的块存储基础设施，它具有传统存储区域网络(SAN)的所有特性和优点。
RBD 作为 VMware ESXI datastore 是否支持？
（1）目前来说，RBD是不支持datastore形式。
（2）iSCSI 是支持 datastore 这种方式，可以作为VMware Esxi 虚拟机提供存储功能，性价比非常不错的选择。
1、创建池和镜像
（1）创建池
# ceph osd pool create iscsi-images replicated
# ceph osd pool application enable iscsi-images rbd
（2）创建images
# rbd --pool iscsi-images create --size= 'iscsi-gateway-image001'
# rbd --pool iscsi-images create --size= 'iscsi-gateway-image002'
# rbd --pool iscsi-images create --size= 'iscsi-gateway-image003'
# rbd --pool iscsi-images create --size= 'iscsi-gateway-image004'
（3）显示images
# rbd ls -p iscsi-images
iscsi-gateway-image001
iscsi-gateway-image002
iscsi-gateway-image003
iscsi-gateway-image004
2、deepsea 方式安装iSCSI网关
（1）node001 和 node002节点上安装，编辑policy.cfg 文件
vim /srv/pillar/ceph/proposals/policy.cfg
......
# IGW
role-igw/cluster/node00[-]*.sls
......
（2）运行 stage 2 和 stage 4
# salt-run state.orch ceph.stage.
# salt 'node001*' pillar.items
public_network:
192.168.2.0/
roles:
- mon
- mgr
- storage
- igw
time_server:
admin.example.com
# salt-run state.orch ceph.stage.
3、手动方式安装iSCSI网关
（1）node003 节点安装 iscsi 软件包
# zypper -n in -t pattern ceph_iscsi
# zypper -n in tcmu-runner tcmu-runner-handler-rbd \
ceph-iscsi patterns-ses-ceph_iscsi python3-Flask python3-click python3-configshell-fb \
python3-itsdangerous python3-netifaces python3-rtslib-fb \
python3-targetcli-fb python3-urwid targetcli-fb-common
（2）admin节点创建key,并复制到 node003
# ceph auth add client.igw.node003 mon 'allow *' osd 'allow *' mgr 'allow r'
# ceph auth get client.igw.node003
client.igw.node003
key: AQC0eotdAAAAABAASZrZH9KEo0V0WtFTCW9AHQ==
caps: [mgr] allow r
caps: [mon] allow *
caps: [osd] allow *
# ceph auth get client.igw.node003 >> /etc/ceph/ceph.client.igw.node003.keyring
# scp /etc/ceph/ceph.client.igw.node003.keyring node003:/etc/ceph
（3）node003 节点启动服务
# systemctl start tcmu-runner.service
# systemctl enable tcmu-runner.service
（4）node003 节点创建配置文件
# vim /etc/ceph/iscsi-gateway.cfg
[config]
cluster_client_name = client.igw.node003
pool = iscsi-images
trusted_ip_list = 192.168.2.42,192.168.2.40,192.168.2.41
minimum_gateways =
fqdn_enabled=true # Additional API configuration options are as follows, defaults shown.
api_port =
api_user = admin
api_password = admin
api_secure = false # Log level
logger_level = WARNING
（5）启动 RBD target 服务
# systemctl start rbd-target-api.service
# systemctl enable rbd-target-api.service
（6）显示配置信息
# gwcli info
HTTP mode : http
Rest API port :
Local endpoint : http://localhost:5000/api
Local Ceph Cluster : ceph
2ndary API IP's : 192.168.2.42,192.168.2.40,192.168.2.41
# gwcli ls
o- / ...................................................................... [...]
o- cluster ...................................................... [Clusters: ]
| o- ceph ......................................................... [HEALTH_OK]
| o- pools ....................................................... [Pools: ]
| | o- iscsi-images ........ [(x3), Commit: .00Y/15718656K (%), Used: 192K]
| o- topology ............................................. [OSDs: ,MONs: ]
o- disks .................................................... [.00Y, Disks: ]
o- iscsi-targets ............................ [DiscoveryAuth: None, Targets: ]
4、Dashboard 添加 iscsi 网关
（1）Admin节点上，查看 dashboard iSCSI 网关
admin:~ # ceph dashboard iscsi-gateway-list
{"gateways": {"node002.example.com": {"service_url": "http://admin:[email protected]:5000"},
"node001.example.com": {"service_url": "http://admin:[email protected]:5000"}}}
（2）添加 iSCSI 网关
# ceph dashboard iscsi-gateway-add http://admin:[email protected]:5000
# ceph dashboard iscsi-gateway-list
{"gateways": {"node002.example.com": {"service_url": "http://admin:[email protected]:5000"},
"node001.example.com": {"service_url": "http://admin:[email protected]:5000"},
"node003.example.com": {"service_url": "http://admin:[email protected]:5000"}}}
（3）登陆 Dashboard 查看 iSCSI 网关
5、Export RBD Images via iSCSI
（1）创建 iSCSI target name
# gwcli
gwcli > /> cd /iscsi-targets
gwcli > /iscsi-targets> create iqn.2019-10.com.suse-iscsi.iscsi01.x86:iscsi-gateway01
（2）添加 iSCSI 网关
gwcli > /iscsi-targets> cd iqn.2019-10.com.suse-iscsi.iscsi01.x86:iscsi-gateway01/gateways
/iscsi-target...tvol/gateways> create node001.example.com 172.200.50.40
/iscsi-target...tvol/gateways> create node002.example.com 172.200.50.41
/iscsi-target...tvol/gateways> create node003.example.com 172.200.50.42 /iscsi-target...ay01/gateways> ls
o- gateways ......................................................... [Up: 3/3, Portals: 3]
o- node001.example.com ............................................. [172.200.50.40 (UP)]
o- node002.example.com ............................................. [172.200.50.41 (UP)]
o- node003.example.com ............................................. [172.200.50.42 (UP)]
注意：安装主机名来定义
/iscsi-target...tvol/gateways> create node002 172.200.50.41
The first gateway defined must be the local machine
（3）添加 RBD 镜像
/iscsi-target...tvol/gateways> cd /disks
/disks> attach iscsi-images/iscsi-gateway-image001
/disks> attach iscsi-images/iscsi-gateway-image002
（4）target 和 RBD 镜像建立映射关系
/disks> cd /iscsi-targets/iqn.2019-10.com.suse-iscsi.iscsi01.x86:iscsi-gateway01/disks
/iscsi-target...teway01/disks> add iscsi-images/iscsi-gateway-image001
/iscsi-target...teway01/disks> add iscsi-images/iscsi-gateway-image002
（5）设置不验证
gwcli > /> cd /iscsi-targets/iqn.2019-10.com.suse-iscsi.iscsi01.x86:iscsi-gateway01/hosts
/iscsi-target...teway01/hosts> auth disable_acl
/iscsi-target...teway01/hosts> exit
（6）查看配置信息
node001:~ # gwcli ls
o- / ............................................................................... [...]
o- cluster ............................................................... [Clusters: 1]
| o- ceph .................................................................. [HEALTH_OK]
| o- pools ................................................................ [Pools: 1]
| | o- iscsi-images .................. [(x3), Commit: 6G/15717248K (40%), Used: 1152K]
| o- topology ...................................................... [OSDs: 6,MONs: 3]
o- disks ................................................................ [6G, Disks: 2]
| o- iscsi-images .................................................. [iscsi-images (6G)]
| o- iscsi-gateway-image001 ............... [iscsi-images/iscsi-gateway-image001 (2G)]
| o- iscsi-gateway-image002 ............... [iscsi-images/iscsi-gateway-image002 (4G)]
o- iscsi-targets ..................................... [DiscoveryAuth: None, Targets: 1]
o- iqn.2019-10.com.suse-iscsi.iscsi01.x86:iscsi-gateway01 .............. [Gateways: 3]
o- disks ................................................................ [Disks: 2]
| o- iscsi-images/iscsi-gateway-image001 .............. [Owner: node001.example.com]
| o- iscsi-images/iscsi-gateway-image002 .............. [Owner: node002.example.com]
o- gateways .................................................. [Up: 3/3, Portals: 3]
| o- node001.example.com ...................................... [172.200.50.40 (UP)]
| o- node002.example.com ...................................... [172.200.50.41 (UP)]
| o- node003.example.com ...................................... [172.200.50.42 (UP)]
o- host-groups ........................................................ [Groups : 0]
o- hosts .................................................... [Hosts: 0: Auth: None]
6、使用 Dashboard 界面输出 RBD Images
（1）添加 iSCSI target
（2）编写 target IQN，并且添加镜像 Portals 和 images
（3）查看新添加 iSCSI target 信息
7、Linux 客户端访问
（1）启动 iscsid 服务
- SLES or RHEL
# systemctl start iscsid.service
# systemctl enable iscsid.service
- Debian or Ubuntu
# systemctl start open-iscsi
（2）发现和连接 targets
# iscsiadm -m discovery -t st -p 172.200.50.40
172.200.50.40:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway01
172.200.50.41:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway01
172.200.50.42:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway01
172.200.50.40:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway02
172.200.50.41:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway02
172.200.50.42:, iqn.-.com.suse-iscsi.iscsi01.x86:iscsi-gateway02
（3）登录target
# iscsiadm -m node -p 172.200.50.40 --login
# iscsiadm -m node -p 172.200.50.41 --login
# iscsiadm -m node -p 172.200.50.42 --login
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda : 25G disk
├─sda1 : 509M part /boot
└─sda2 : .5G part
├─vg00-lvswap : 2G lvm [SWAP]
└─vg00-lvroot : .5G lvm /
sdb : 100G disk
└─vg00-lvroot : .5G lvm /
sdc : 2G disk
sdd : 2G disk
sde : 4G disk
sdf : 4G disk
sdg : 2G disk
sdh : 4G disk
sdi : 2G disk
sdj : 4G disk
sdk : 2G disk
sdl : 2G disk
sdm : 4G disk
sdn : 4G disk
（4）如果系统上已安装 lsscsi 实用程序，您可以使用它来枚举系统上可用的 SCSI 设备：
# lsscsi
[:::] cd/dvd NECVMWar VMware SATA CD01 1.00 /dev/sr0
[:::] disk VMware, VMware Virtual S 1.0 /dev/sda
[:::] disk VMware, VMware Virtual S 1.0 /dev/sdb
[:::] disk SUSE RBD 4.0 /dev/sdc
[:::] disk SUSE RBD 4.0 /dev/sde
[:::] disk SUSE RBD 4.0 /dev/sdd
[:::] disk SUSE RBD 4.0 /dev/sdf
[:::] disk SUSE RBD 4.0 /dev/sdg
[:::] disk SUSE RBD 4.0 /dev/sdh
[:::] disk SUSE RBD 4.0 /dev/sdi
[:::] disk SUSE RBD 4.0 /dev/sdj
[:::] disk SUSE RBD 4.0 /dev/sdk
[:::] disk SUSE RBD 4.0 /dev/sdm
[:::] disk SUSE RBD 4.0 /dev/sdl
[:::] disk SUSE RBD 4.0 /dev/sdn
（5）多路径设置
# zypper in multipath-tools
# modprobe dm-multipath path
# systemctl start multipathd.service
# systemctl enable multipathd.service
# multipath -ll
36001405863b0b3975c54c5f8d1ce0e01 dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| `- ::: sdh : active ready running <=== 单条链路 active
`-+- policy='service-time 0' prio= status=enabled
|- ::: sde : active ready running
`- ::: sdm : active ready running
3600140529260bf41c294075beede0c21 dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio= status=active
| `- ::: sdc : active ready running
`-+- policy='service-time 0' prio= status=enabled
|- ::: sdg : active ready running
`- ::: sdk : active ready running
360014055d00387c82104d338e81589cb dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio= status=active
| `- ::: sdl : active ready running
`-+- policy='service-time 0' prio= status=enabled
|- ::: sdd : active ready running
`- ::: sdi : active ready running
3600140522ec3f9612b64b45aa3e72d9c dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio= status=active
| `- ::: sdf : active ready running
`-+- policy='service-time 0' prio= status=enabled
|- ::: sdj : active ready running
`- ::: sdn : active ready running
（5）编辑多路径配置文件
# vim /etc/multipath.conf
defaults {
user_friendly_names yes
} devices {
device {
vendor "(LIO-ORG|SUSE)"
product "RBD"
path_grouping_policy "multibus" # 所有有效路径在一个优先组群中
path_checker "tur" # 在设备中执行 TEST UNIT READY 命令。
features ""
hardware_handler "1 alua" # 在切换路径组群或者处理 I/O 错误时用来执行硬件具体动作的模块。
prio "alua"
failback "immediate"
rr_weight "uniform" # 所有路径都有相同的加权
no_path_retry # 路径故障后，重试12次，每次5秒
rr_min_io # 指定切换到当前路径组的下一个路径前路由到该路径的 I/O 请求数。
}
}
# systemctl stop multipathd.service
# systemctl start multipathd.service
（6）查看多路径状态
# multipath -ll
mpathd (3600140522ec3f9612b64b45aa3e72d9c) dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
`-+- policy='service-time 0' prio= status=active
|- ::: sdf : active ready running <=== 多条链路 active
|- ::: sdj : active ready running
`- ::: sdn : active ready running
mpathc (360014055d00387c82104d338e81589cb) dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
`-+- policy='service-time 0' prio= status=active
|- ::: sdd : active ready running
|- ::: sdi : active ready running
`- ::: sdl : active ready running
mpathb (36001405863b0b3975c54c5f8d1ce0e01) dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
`-+- policy='service-time 0' prio= status=active
|- ::: sde : active ready running
|- ::: sdh : active ready running
`- ::: sdm : active ready running
mpatha (3600140529260bf41c294075beede0c21) dm- SUSE,RBD
size=.0G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
`-+- policy='service-time 0' prio= status=active
|- ::: sdc : active ready running
|- ::: sdg : active ready running
`- ::: sdk : active ready running
（7）显示当前的device mapper的信息
# dmsetup ls --tree
mpathd (:)
├─ (:)
├─ (:)
└─ (:)
mpathc (:)
├─ (:)
├─ (:)
└─ (:)
mpathb (:)
├─ (:)
├─ (:)
└─ (:)
mpatha (:)
├─ (:)
├─ (:)
└─ (:)
vg00-lvswap (:)
└─ (:)
vg00-lvroot (:)
├─ (:)
└─ (:)
（8）客户端 yast iscsi-client 工具查看
iSCSI的其他常用操作（客户端）
（1）列出所有target
# iscsiadm -m node
（2）连接所有target
# iscsiadm -m node -L all
（3）连接指定target
# iscsiadm -m node -T iqn.... -p 172.29.88.62 --login
（4）使用如下命令可以查看配置信息
# iscsiadm -m node -o show -T iqn.-.com.synology:rackstation.exservice-bak
（5）查看目前 iSCSI target 连接状态
# iscsiadm -m session
# iscsiadm: No active sessions.
(目前没有已连接的 iSCSI target)
（6）断开所有target
# iscsiadm -m node -U all
（7）断开指定target
# iscsiadm -m node -T iqn... -p 172.29.88.62 --logout
（8）删除所有node信息
# iscsiadm -m node --op delete
（9）删除指定节点（/var/lib/iscsi/nodes目录下，先断开session）
# iscsiadm -m node -o delete -name iqn.-.cn.nayun:test-
（10）删除一个目标（/var/lib/iscsi/send_targets目录下）
# iscsiadm --mode discovery -o delete -p 172.29.88.62: