Home > Equallogic, Hyper-V, Networking, Windows 2008 R2 > Equallogic 7.4.3 CHAP user mpio Authentication failed

Equallogic 7.4.3 CHAP user mpio Authentication failed

Sometime ago I had an issue with a target on one of my customers servers (Windows Server 2008 Core) and an Equallogic PS5000XV. The issues was the error message below.

Event 7.4.3
1-7-09 13:57:28
iSCSI login to target ‘, iqn.2001-05.com.equallogic:0-8a0906-bbb8ad503-b53d4d74e944a34d-000-srv666-hd00′ from initiator ‘, iqn.1995-05.com.broadcom.iscsiboot’ failed for the following reason:
CHAP user ‘mpio-000-SRV123-0-8a0906-bbb8ad503-b53d4d74e944a34d-91d1a2′ authentication failed

Obviously somewhere a something went wrong or a bit fell over. Anyhow…this error sucks because little info can be found on the Internet regarding this issue.

What to do?

First of all: Before you start make sure no active applications, services or Virtual Machines are using the iSCSI target on the specific server.

Remove the persistent tartget from the server with is giving the error. In my case ‘’.

  1. Retrieve the session list with: iSCSIcli sessionlist > C:\Temp\sessionlist.txt. Below my SessionID example: sessioninfo
  2. Look for the following info: Initiator Name, TargetName and Target Portal for the target that is reporting the issues;
  3. Fill in the found info in the following iSCSICLI command: iSCSIcli RemovePersistentTarget <Initiator Name> <TargetName> * TargetPortal 3260. In my case this would be: iscsicli RemovePersistentTarget Root\ISCSIPRT\0000_0 iqn.2001-05.com.equallogic:0-8a0906-bbb8ad503-b53d4d74e944a34d-000-srv666-hd00 * 3260;
  4. Log-out all existing sessions that the target is using with: iSCSIcli LogoutTarget <SessionId>. In my case this would be: iSCSIcli LougoutTarget fffffa8029687018-400001370000041d. Logout ALL found SessionID’s for the specific TargetName.
  5. Open regedit.exe and make a back-up of HKEY_LOCAL_MACHINE\SOFTWARE\EqualLogic\EHCM\MpioChap
  6. Search in regedit.exe on the troubled server for “‘mpio-000-SRV123-0-8a0906-bbb8ad503-b53d4d74e944a34d-91d1a2″ and delete it! Mine looked like this in an export.mpio_reg
  7. After delting the registry key rebuild the persistent target on the troubled server to the specific target. Do this with iSCSIcli PersistentLoginTarget TargetName T * * * * * * * * * * * * * * * 0. Mine looked like this iSCSIcli PersistentLoginTarget iqn.2001-05.com.equallogic:0-8a0906-bbb8ad503-b53d4d74e944a34d-000-srv666-hd00 T * * * * * * * * * * * * * * * 0.

As you can check in your Equallogic Group Manager you will find that now for each NIC in your server which is connected to the iSCSI VLAN a Session is made.

mpio error

The and have been reconnected. Previouslu only the session would show up!

  1. Rob
    June 23rd, 2010 at 16:39 | #1

    I’m having the same issue, unfortunately, your fix did not work. The server is Win2008 R2. MPIO will work, but only from one NIC at a time, the other generates the error.

  2. Rob
    June 23rd, 2010 at 18:52 | #2

    Asked EQ tech support, and here was the fix for us. Go into the group config tab, iSCSI tab, iSCSI Initiator Configuration, enable the check box for “Consult locally defined CHAP accounts first” and that immediately fixed the problem.

  3. Ian O B
    September 8th, 2010 at 10:15 | #3

    I too had the same problem and enabled the checkbox ““Consult locally defined CHAP accounts first”. It worked and errors are now gone. What worried me was why this “worked” so I have looked into it further and it seems to be the case that by default chap is enable or at least a chap username and randomly created chap password is setup. If you enable the check box above and remove the chap password requirements it also works. It seems like whether you enable chap yourself or not it will always default with chap and you need to either enable or disable it..would be interested to see if other people have further thoughts on this. thanks

  4. Michael
    October 25th, 2010 at 21:48 | #4

    Kudos gentlemen (Rob and Ian O B) I have been troubleshooting the issue for a while now and this is the first info that i have found that A)made sense, and B)worked! Thank you both for your input!

    • admin
      October 30th, 2010 at 11:32 | #5

      FYI: Original posting was for Windows 2008 RTM1, not R2.

  5. Jack
    November 4th, 2010 at 03:54 | #6


    Rob, I am having a similar problem that only 1 NIC works at a time, no CHAP used.
    All two sessions showed up, but still using just one link at a time.

    PS6000XV and W2K8 R2.


    Any solution? Thanks.

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