SOLVED by Mike. I'm sorry I did not see it at first time, but I accidentally installed the i686 version of the iscsiadm-utils package. What was weird though was that using this 32bits tool was successful for discovering the targets. But it wasn't able to login.
I made a good cleanup into my packages, re-installed the 64 bits version, according to my arch, and the login is doing fine. Thank you Mike for the time you took to answer me. Have a nice day. -- Nicolas Ecarnot -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
