LUN discovery fails due to iSCSI daemon limitation

Contributors netapp-ivanad Download PDF of this page

SnapDrive for UNIX commands fail to discover the LUNs after continuous multiple iterations.

You may see the following error message.

0000-001 Admin error: iscsi transport protocol has dropped sessions in the host. Please ensure the connection and the service in the storage system.

This happens because of the iSCSI daemon limitation in the following hosts:

  • Red Hat Enterprise Linux 4.0

  • Oracle Enterprise Linux 4.0

Workaround

Before modifying the following system parameters, contact the OS vendor.
  1. Add the fs.file-max parameter to the /etc/sysctl.conf file.

    The following is an example in the command-line.

    # sysctl -w fs.file-max=65536
    Note We recommend to set the parameter value to 65536, but you can also set the value depending on the applications on your host.
  2. Assign 65536 to the fs.file-max parameter.

  3. Update the default shell start-up file for the root user’s UNIX account.

    • For the Bourne, Bash, or Korn shell, add the following lines to the /etc/profile file by running the following command:

      cat >> /etc/profile <<EOF
      if [ \$USER = "root" ]; then
      if [ \$SHELL = "/bin/ksh" ]; then
      ulimit -p 16384
      ulimit -n 65536
      else
      ulimit -u 16384 -n 65536
      fi
      umask 022
      fi
      EOF
    • For the C shell (csh or tcsh), add the following lines to the /etc/csh.login file by running the following command:

      cat >> /etc/csh.login <<EOF
      if ( \$USER == "root" ) then
      limit maxproc 16384
      limit descriptors 65536
      endif
      EOF
  4. Add the following parameters to the /etc/security/limits.conf file by running the following command:

    root soft nofile 65536
    root hard nofile 65536
  5. Activate all the kernel parameters for the system by executing the following command: sysctl -p