Managing open system hosts through the DS8000 Storage Management GUI introduced in Release 7.4 can cause changes to existing LUN mappings. This can cause a loss of access to data.
A new user interface, the DS8000 Storage Management GUI, was introduced in Release 7.4, 22.214.171.124. The new GUI adds a definition for open systems hosts, which was not included in previous microcode levels. As a result, using the new GUI to make configuration changes to a DS8000 storage system that was configured on an earlier microcode level might result in changes that seriously affect hosts using LUN mapping, such as Linux. CKD configurations are unaffected. AIX and SAN Volume Controller (SVC) hosts use LUN masking and are not exposed to this problem.
When logging in to the new GUI or after making configuration changes using DSCLI, a window is displayed that lists unassigned host ports, If you are using a host that uses LUN Mapping, do not assign these ports. Problems can occur when you assign an unassigned host port to a host that uses LUN Mapping in the new GUI. This includes the Update Host Ports action that was displayed when you first opened the Hosts page.
If you use the Update Host Ports action in the new GUI, new volume groups are created. In some rare cases, the LUN ID mappings of these new volume groups do not match the previous mappings. If this happens, the host loses access to the storage system.
Hosts exposed to this issue include any host connection with an address discovery of "LUN Polling" as seen in DSCLI. This includes the following hosts:
N Series Gateway®
Linux RHEL®, Linux SUSE®, Linux Red Flag®, Linux Desktop®, pLinux®, iLinux®, IBM Linux/SanFS®
Windows 2003®, Windows 2008®, Windows 2012®
HP-Tru64®, HP Open VMS®
1.) To prevent the problem using the new GUI on R7.4 microcode level 126.96.36.199 or 188.8.131.52, do not assign host ports that are unassigned.
When logging in to the new GUI, do not use the Update host port assignment action. In the Update Host Ports window, click cancel.
2.) When you log in to the new GUI, there are three places where you can choose to update unassigned host ports. Do not complete these actions.
1. When you open the Hosts page, a task launcher is displayed.
2. When you click the notice at the upper right corner of the Hosts table.
3. When you right-click the Unassigned Host Ports row, and select the Update Host Ports action.
3.) Use the Previous GUI to make configuration changes. You can access the Previous GUI from the Help menu in the upper right corner.
Installation of microcode bundle 184.108.40.206 (R7.4 SP1) or higher will restore full functionality to the DS8000 Storage Management GUI.
17 June 2018