flyinweb's blog

常用操作命令：
查看当前虚拟单元清单。
cat /proc/net/iet/volume

查看当前服务器 ISCSI target 服务以及连接状态命令
cat /proc/net/iet/sessions


关于ISCSI Target 的配置，常用有两种方式：
1.修改配置文件
vi /etc/ietd.conf

2.使用IET管理命令行
添加一个新的 target
ietadm --op new --tid=[id] --params Name=iqn.foo.bar:baz

其中[id] 为数字，必须是没有使用过的。后面的Name 需要自己自定义，也需要保证是唯一的。
当然不知道自己本机所有target id 的话，可以使用这个命令查看当前的target 状态和得到target id.
查看当前服务器 ISCSI target 服务以及连接状态命令
cat /proc/net/iet/sessions

添加一个新的 lun
Note:在一个已经存在的 target 上加入一个lun,以便共享出来给外界。
ietadm --op new --tid=[id] --lun=[lun] --params Path=/path/to/exported/file,Type=fileio

[id] 必须是一个已经存在的tid 号，[lun]可以自己定义。
后面的path 我就不需要多说了，就是共享的路径了。
关于ietadm 其余的命令，大家可以使用 ietadm --help 来查看更多的指令。

所有的配置更改过后，大家别忘重启iscsi 服务。
service iscsi-target restart
强力推荐一个非常好的介绍配置的网站：
http://www.linuxtopia.org/online_books/suse_linux_guides/SLES10/suse_enterprise_linux_server_installation_admin/sec_inst_system_iscsi_target.html

其他常见问题
1.防火墙链接限制，外界无法访问Target 服务器3260 端口。
请在防火墙上手动放开 3260 端口，或者有条件的话干脆关闭防火墙。
更改防火墙配置并重启生效
vi /etc/sysconfig/iptables
server iptable restart

2.共享的路径都可以有哪些？
在IET 的技术文档中规定，以下几种路径是被支持的：
1)一个完整的block 磁盘，比如我在前文中所述的 /dev/sdb。
2)一个RAID 设备或者是一个 LVM ,这个我没测试过！-_-!
3)一个虚拟的镜像文件,可能性能可比直接IO 读取稍差点！
例子：
制作一个512M 的磁盘镜像
dd if=/dev/zero of=/disk.img bs=512 count=1000000

IET 配置中lun 设置：
LUN 0 Path=/disk.img,Type=fileio

重启IET服务生效！

[root@localhost iet]# ietadm --help
Usage: ietadm [OPTION]
iSCSI Enterprise Target Administration Utility.

  --op new --tid=[id] --params Name=[name]
                        add a new target with [id]. [id] must not be zero.
  --op delete --tid=[id]
                        delete specific target with [id]. The target must
                        have no active sessions.
  --op show --tid=[id]
                        show target parameters of target with [id].
  --op show --tid=[id] --sid=[sid]
                        show iSCSI parameters in effect for session [sid]. If
                        [sid] is "0" (zero), the configured parameters
                        will be displayed.
  --op show --tid=[id] --user
                        show list of Discovery (--tid omitted / id=0 (zero))
                        or target CHAP accounts.
  --op show --tid=[id] --user --params=[user]=[name]
                        show CHAP account information. [user] can be
                        "IncomingUser" or "OutgoingUser". If --tid is
                        omitted / id=0 (zero), [user] is treated as Discovery
                        user.
  --op new --tid=[id] --lun=[lun] --params Path=[path]
                        add a new logical unit with [lun] to specific
                        target with [id]. The logical unit is offered
                        to the initiators. [path] must be block device files
                        (including LVM and RAID devices) or regular files.
  --op delete --tid=[id] --lun=[lun]
                        delete specific logical unit with [lun] that
                        the target with [id] has.
  --op delete --tid=[id] --sid=[sid] --cid=[cid]
                        delete specific connection with [cid] in a session
                        with [sid] that the target with [id] has.
                        If the session has no connections after
                        the operation, the session will be deleted
                        automatically.
  --op delete           stop all activity.
  --op update --tid=[id] --params=key1=value1,key2=value2,...
                        change iSCSI IET target parameters of specific
                        target with [id]. You can use parameters in ietd.conf
                        as a key.
  --op new --tid=[id] --user --params=[user]=[name],Password=[pass]
                        add a new account with [pass] for specific target.
                        [user] could be [IncomingUser] or [OutgoingUser].
                        If you don't specify a target (omit --tid option),
                        you add a new account for discovery sessions.
  --op delete --tid=[id] --user --params=[user]=[name]
                        delete specific account having [name] of specific
                        target. [user] could be [IncomingUser] or
                        [OutgoingUser].
                        If you don't specify a target (omit --tid option),
                        you delete the account for discovery sessions.
  --op update --tid=[id] --redirect=[dest]
                        redirect login to target with tid [id] to portal
                        [dest]. Discovery sessions will not be impacted,
                        but normal sessions will be redirected before
                        security negotiation. The destination should be
                        specified using the format:
                                <ip_addr>[:port]
                        IPv6 addresses need to be enclosed in [] brackets
                        To clear, provide an empty string
  --version             display version and exit
  --help                display this help and exit

Report bugs to <iscsitarget-devel@sourceforge.net>.