# Known Issues

### Windows Known Issues

- #### Microsoft Initiator does not boot without link on boot port:

  After setting up the system for Intel® Ethernet iSCSI Boot with two ports connected to a target and successfully booting the system, if you later try to boot the system with only the secondary boot port connected to the target, Microsoft Initiator will continuously reboot the system.

  To work around this limitation follow these steps:

  1. Using Registry Editor, expand the following registry key:
     HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
  2. Create a DWORD value called DisableDHCPMediaSense and set the value to 0.

- #### Moving iSCSI adapter to a different slot:

  In a Windows* installation, if you move the iSCSI adapter to a PCI slot other than the one that it occupied when the drivers and MS iSCSI Remote Boot Initiator were installed, then a System Error may occur during the middle of the Windows Splash Screen. This issue goes away if you return the adapter to its original PCI slot. We recommend not moving the adapter used for iSCSI boot installation. This is a known OS issue.

  If you have to move the adapter to another slot, then perform the following:

  1. Boot the operating system and remove the old adapter
  2. Install a new adapter into another slot
  3. Setup the new adapter for iSCSI Boot
  4. Perform iSCSI boot to the OS via the original adapter
  5. Make the new adapter iSCSI-bootable to the OS
  6. Reboot
  7. Move the old adapter into another slot
  8. Repeat steps 2 - 5 for the old adapter you have just moved

- #### Uninstalling Driver can cause blue screen

  If the driver for the device in use for iSCSI Boot is uninstalled via Device Manager, Windows will blue screen on reboot and the OS will have to be re-installed. This is a known Windows issue.

- #### Adapters flashed with iSCSI image are not removed from the Device Manager during uninstall

  During uninstallation all other Intel Network Connection Software is removed, but drivers for iSCSI Boot adapters that have boot priority.

- #### I/OAT Offload may stop with Intel® Ethernet iSCSI Boot or with Microsoft Initiator installed

  A workaround for this issue is to change the following registry value to "0":

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IOATDMA\Start

  Only change the registry value if iSCSI Boot is enabled and if you want I/OAT offloading. A blue screen will occur if this setting is changed to "0" when iSCSI Boot is not enabled. It must be set back to "3" if iSCSI Boot is disabled or a blue screen will occur on reboot.

- #### NDIS Driver May Not Load During iSCSI Boot F6 Install With Intel® PRO/1000 PT Server Adapter

  If you are using two Intel® PRO/1000 PT Server Adapters in two PCI Express x8 slots of a rack mounted Xeon system, Windows installation can be done only via a local HDD procedure.

- #### Invalid CHAP Settings May Cause Windows® Server 2008 to Blue Screen

  If an iSCSI Boot port CHAP user name and secret do not match the target CHAP user name and secret, Windows Server 2008 may blue screen or reboot during installation or boot. Ensure that all CHAP settings match those set on the target(s).

- #### F6 Driver Does Not Support Standby Mode.

  If you are performing an F6 Windows without a Local Disk installation, do not use Standby Mode.

- #### Microsoft* Windows Server* 2008 Installation When Performing a WDS Installation

  If you perform a WDS installation and attempt to manually update drivers during the installation, the drivers load but the iSCSI Target LUN does not display in the installation location list. This is a known WDS limitation with no current fix. You must therefore either perform the installation from a DVD or USB media or inject the drivers on the WDS WinPE image.

  Microsoft has published a knowledge base case explaining the limitation in loading drivers when installing with iSCSI Boot via a WDS server.
  http://support.microsoft.com/kb/960924

- #### iSCSI Boot and Teaming in Windows

  Teaming is not supported with iSCSI Boot. Creating a team using the primary and secondary iSCSI adapters and selecting that team during the Microsoft initiator installation may fail with constant reboots. Do not select a team for iSCSI Boot, even if it is available for selection during initiator installation.

  For load balancing and failover support, you can use MSFT MPIO instead. Check the Microsoft Initiator User Guide on how to setup MPIO.

- #### Setting LAA (Locally Administered Address) on an iSCSI Boot-Enabled Port Will Cause System Failure on Next Reboot

  Do not set LAA on ports with iSCSI Boot enabled.

- #### F6 installation may fail with some EMC targets

  An F6 installation may fail during the reboot in step 10 of “Installing Windows 2003 without a Local Disk” because of a conflict between the Intel F6 driver, the Microsoft iSCSI Initiator and the following EMC target model firmware versions:

  > AX4-5 arrays: 02.23.050.5.705 or higher
  > CX300, CX500, CX700, and CX-3 Series arrays: 03.26.020.5.021 or higher.
  > CX-4 Series arrays: 04.28.000.5.701 or higher, including all 04.29.000.5.xxx revisions.

  To avoid the failure, ensure that the secondary iSCSI port cannot reach the target during the reboot in step 10.

- #### With high iSCSI traffic on Microsoft* Windows 2003 Server* R2, link flaps can occur with 82598-based silicon

  This issue is caused by the limited support for Large Send Offload (LSO) in this Operating System. Please note that if ISCSI traffic is required for Windows 2003 Server R2, LSO will be disabled.

- #### Intel® Ethernet iSCSI Boot version does not match between displayed verions on DMIX and the scrolling text during boot

  If a device is not set to primary but is enumerated first, the BIOS will still use that device's version of iSCSI Boot. Therefore the user may end up using an earlier version of Intel® Ethernet iSCSI Boot than expected. The solution is that all devices in the system must have the same version of iSCSI Boot. To do this the user should go to the Boot Options Tab and update the devices' flash to the latest version.

- #### IPv6 iSCSI login to Dell EqualLogic arrays using jumbo frames

  To establish an iSCSI session using IPv6 and jumbo frames with Dell EqualLogic arrays, TCP/UDP checksum offloads on the Intel iSCSI adapter should be disabled.

### iSCSI/DCB Known Issues

- #### iSCSI over DCB using Microsoft* Windows Server* 2012

  iSCSI over DCB (priority tagging) is not possible on the port on which VMSwitch is created. This is is by design in Microsoft* Windows Server* 2012.

- #### Automatic creation of iSCSI traffic filters for DCB is only supported on networks which make use of IPv4 addressing

  The iSCSI for Data Center Bridging (DCB) feature uses Quality of Service (QOS) traffic filters to tag outgoing packets with a priority. The Intel iSCSI Agent dynamically creates these traffic filters as needed on networks using IPv4 addressing.

- #### Automatic creation of iSCSI traffic filters for DCB, using Virtual Adapters created by Hyper-V, is only supported on Microsoft* Windows Server* 2008 releases R2 and later.

  The iSCSI for Data Center Bridging (DCB) feature uses Quality of Service (QOS) traffic filters to tag outgoing packets with a priority. The Intel iSCSI Agent dynamically creates these traffic filters as needed for Windows Server 2008 R2 and later.

- #### IPv6 iSCSI login to Dell EqualLogic arrays using jumbo frames

  To establish an iSCSI session using IPv6 and jumbo frames with Dell EqualLogic arrays, TCP/UDP checksum offloads on the Intel iSCSI adapter should be disabled.

### Linux Known Issues

- #### Authentications errors on EqualLogic target may show up in dmesg when running Red Hat* Enterprise Linux 4

  These error messages do not indicate a block in login or booting and may safely be ignored.

- #### Channel Bonding

  Linux Channel Bonding has basic compatibility issues with iSCSI Boot and should not be used.

- #### iBFT System using RHEL 5.2

  In an iBFT system using RHEL 5.2, Anaconda does not automatically start networking upon installation. The user has to manually bring up networking through a console. Please refer to the RedHat documentation for details on how to manually force up the network.

- #### CHAP Support with RHEL 5.2

  RHEL 5.2 does not support CHAP during installation time. If you use CHAP authentication on the target, please disable CHAP during installation and enable it after the installation is complete.

- #### RHEL 5.1

  On RHEL5.1 systems, the wrong network interface is brought up on the first iSCSI Boot after installation. This causes the system to hang and requires a reinstallation at the very least. The workaround for this issue is to edit the init script soon after installation and change the interface you wish to bring up. We strongly encourage our users to use RHEL5.2 to avoid this issue.

- #### LRO and iSCSI Incompatibility

  LRO (Large Receive Offload) is incompatible with iSCSI target or initiator traffic. A panic may occur when iSCSI traffic is received through the ixgbe driver with LRO enabled. To workaround this, the driver should be built and installed with:

  > # make CFLAGS_EXTRA=-DIXGBE_NO_LRO install

- #### RHEL 5.X

  From a remote LUN, iSCSI boot only works on the same port that was used to install to the remote LUN. You cannot boot from an alternate LAN port after iSCSI is install.

`Last modified on 4/24/13.`