RHEL 6 – ISCSI Administration Series – Configuring ISCSI Server and Client

Ramdev

I have started unixadminschool.com ( aka gurkulindia.com) in 2009 as my own personal reference blog, and later sometime i have realized that my leanings might be helpful for other unixadmins if I manage my knowledge-base in more user friendly format. And the result is today's' unixadminschool.com. You can connect me at - https://www.linkedin.com/in/unixadminschool/

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22 Responses

  1. sreenath says:

    Nice Sir,Keep it Up!

  2. Elumalai M says:

    Thanks for sharing this article. 

    In the client side If I want to remove the one LUN (one mapped new disk). What action to be done in client and server ? Thanks in advance for clarification…

    • Ramdev says:

      Hi Elumalai, storage on iscsi individual luns are quite buggy in real time world. And normally we do work with the strategy “one lun – one target relation”, so that it is to manage things like access control and Lun maintenance without reboots. I will be covering some of the tasks in my continuation post.

  3. Elumalai M says:

    Hi Ramdev,

    ok… Thanks for your explanation…

  4. Santhosh Kumar Reddy says:

    A Very good documentation.

  5. krishgudd says:

    Hi Ramdev,

    Inside the /var/lib/iscsi/nodes directory we will get the node information right.What happens if I delete that .

    In one our server when I execute iscsiadm -m node its showing nothing and nothing inside /var/lib/iscsi/node directory . but Iam using lun which is coming from that target.

  6. chetan Panchal says:

    Hi

    May i requested to you Please share Redhat cluster suite for RHEL6?

  7. Animesh Singha says:

    after reboot , shared drive not shown ..missing..

    please help me urgently

  8. Ramdev says:

    Animesh, please folllow the step3 ( as mentioned below) to redetect the luns.. you need to use the your iscsi server ip instead of 192.168.1.30.   Then you will see the shared iscsi luns at the client.

    Step 3: Discovery the targets available from the ISCSI target server and bind to the target

    Run the iscsiadm command in discoverydb mode to get the information of available targets from the iscsi server 192.168.1.30 ( i.e. gurkusan)

    [root@gurkulrhel4 ~]# iscsiadm –mode discoverydb –type sendtargets –portal 192.168.1.30 –discover
    192.168.1.30:3260,1 iqn.2013-04.com.unixadminschool:target1

    Once the target discovered, bind to the target 

    [root@gurkulrhel4 ~]# iscsiadm –mode node –targetname iqn.2013-04.com.unixadminschool:target1 –portal 192.168.1.30 –login
    Logging in to [iface: default, target: iqn.2013-04.com.unixadminschool:target1, portal: 192.168.1.30,3260] (multiple)
    iscsiadm: Could not login to [iface: default, target: iqn.2013-04.com.unixadminschool:target1, portal: 192.168.1.30,3260].
    iscsiadm: initiator reported error (24 – iSCSI login failed due to authorization failure)
    iscsiadm: Could not log into all portals

    above faults appears because the targets were secured by CHAP authentication. We need to provide the authenitcated username and password to bind to the target

  9. kevin says:

    hi,

    Can you show me how to do multi-path for iSCSI ? thanks

  10. Ramdev says:

    Hi Kevin, Sure. I will make a procedure for the ISCSI multipath and will post it soon.

    • Praneeth says:

      Hi Ramdev,

      We have configured iscsi in RHEL 6.7 without multipathing & working fine.But with multipathing we are facing problem.Can u provide iscsi multipathing configuration.

      While creating file system we are getting below error.

      sd 12:0:0:1: SCSI error: return code = 0x06000000
      end_request: I/O error, dev sdatk, sector 2109640
      Aborting journal on device dm-785.
      __journal_remove_journal_head: freeing b_committed_data
      journal commit I/O error
      ext3_abort called.
      EXT3-fs error (device dm-785): ext3_journal_start_sb: Detected aborted journal
      Remounting filesystem read-only
      ext3_abort called.
      EXT3-fs error (device dm-785): ext3_put_super: Couldn’t clean up the journal

  11. anand says:

    Hi,
    By default, iSCSI logging done in “/var/log/messages” in RHEL. Is there a way to configure logging in some other file?

  12. Raj says:

    Hi Ramdev and Team,

    Can you please assist on how to resolve the avc {read write} denail issue in SELinux permissions. the server OS version is OEL 6.3 and SELinux must be in Enforcing mode. Can any one pls guide on this issue.

    Thx in advance

    Regards,

    Raj

  13. John says:

    Hi Ram, Thanks for the wonderful explanation. I’m having some trouble in the Client part. I used the CHAP authentication and added that information to /etc/iscsi/iscsid.conf; however, when i try to discover am getting the iqn, but, when i try to login , i get the below error, please advice.

    [root@clusternode2 ~]# iscsiadm –mode node –targetname iqn.2013-04.com.clusterdomain:target1 –portal 192.168.117.171 –login
    Logging in to [iface: default, target: iqn.2013-04.com.clusterdomain:target1, portal: 192.168.117.171,3260] (multiple)
    iscsiadm: Could not login to [iface: default, target: iqn.2013-04.com.clusterdomain:target1, portal: 192.168.117.171,3260].
    iscsiadm: initiator reported error (24 – iSCSI login failed due to authorization failure)
    iscsiadm: Could not log into all portals

    • John says:

      You’ve mentioned as ” faults appears because the targets were secured by CHAP authentication. We need to provide the authenticated username and password to bind to the target”, how do I do this?

      • unixadmschool says:

        Hi John, please check the section”And the following file will have all the related information about the discovered target” in step-4.

  14. ravi says:

    Hi,

    My iscsi is never started..am getting error like iscsi is stopped.
    please help
    Thanks in Advance,
    Ravi

  1. September 17, 2015

    […] Read – Configuring ISCSI Server and Client RHEL6 […]

  2. September 18, 2015

    […] Read – Configuring ISCSI Server and Client in RHEL6 […]

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