SAN hosts and cloud clients

Windows Unified Host Utilities Release Notes

The release notes describe new features and enhancements, issues fixed in the current release, known problems and limitations, and important cautions related to configuring and managing your specific Windows host with your ONTAP and SANtricity storage system.

What’s new

Windows Unified Host Utilities 7.2 includes support for NVMe/FC driver parameter settings and bug fixes for new vendor cards.
Windows Unified Host Utilities 7.1 includes support for ETERNUS AB/HB series storage systems, support for ONTAP 9 and later versions, and enhanced iSCSI timeouts for faster failover.

Known problems and limitations

You should be aware of the following known problems and limitations that might impact performance on your specific host. A few unexpected and potentially undesired behaviors, and workarounds to avoid these behaviors, have been identified in the Windows Unified Host Utilities 7.1 release.

Title Description Workaround

Title	Description	Workaround
Running the `linux_gos_timeout-install.sh` script is no longer required on Hyper-V guests running Red Hat Enterprise Linux or SUSE Linux Enterprise Server	You are no longer required to run the `linux_gos_timeout-install.sh` script to change disk timeouts on Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 6, or SUSE Linux Enterprise Server 11 Hyper-V guests because the default timeout settings are being used. The `linux_gos_timeout-install.sh` script that was included in previous versions of the Host Utilities is no longer included in the Windows Unified Host Utilities 7.1 version. Windows Unified Host Utilities 7.1 uses the default disk timeout settings.	Not Applicable
iSCSI sessions do not reconnect after reboot with mixed IPv4 and IPv6	In a multipath I/O (MPIO) configuration or multiple connections per session (MCS) configuration that has both IPv4 and IPv6 endpoints, some iSCSI sessions might fail to reconnect after rebooting the Windows host.	Use either all IPv4 endpoints or IPv6 endpoints. Do not mix IPv4 and IPv6.
Multiple connections per session (MCS) is not supported with iSCSI software boot	When using the iSCSI software boot with iSCSI MCS, the iSCSI boot leading connection cannot be protected. This can lead to disconnection from the boot LUN and cause host system disruption.	Microsoft does not support MCS for iSCSI software booted hosts. Use MPIO as the high availability solution. Note that mixing MPIO and MCS is not supported.

Running the linux_gos_timeout-install.sh script is no longer required on Hyper-V guests running Red Hat Enterprise Linux or SUSE Linux Enterprise Server

You are no longer required to run the linux_gos_timeout-install.sh script to change disk timeouts on Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 6, or SUSE Linux Enterprise Server 11 Hyper-V guests because the default timeout settings are being used. The linux_gos_timeout-install.sh script that was included in previous versions of the Host Utilities is no longer included in the Windows Unified Host Utilities 7.1 version. Windows Unified Host Utilities 7.1 uses the default disk timeout settings.

Not Applicable

iSCSI sessions do not reconnect after reboot with mixed IPv4 and IPv6

In a multipath I/O (MPIO) configuration or multiple connections per session (MCS) configuration that has both IPv4 and IPv6 endpoints, some iSCSI sessions might fail to reconnect after rebooting the Windows host.

Use either all IPv4 endpoints or IPv6 endpoints. Do not mix IPv4 and IPv6.

Multiple connections per session (MCS) is not supported with iSCSI software boot

When using the iSCSI software boot with iSCSI MCS, the iSCSI boot leading connection cannot be protected. This can lead to disconnection from the boot LUN and cause host system disruption.

Microsoft does not support MCS for iSCSI software booted hosts. Use MPIO as the high availability solution. Note that mixing MPIO and MCS is not supported.