IBM Support

Potential loss of access on DS8900F systems with 32Gb Host Adapters

Flashes (Alerts)


Abstract

In DS8900F systems with 32Gb Host Adapters, an irregular Format Write chain may cause Host Adapters to become fenced.

Content

Risk classification

HIPER
Risk categories

Loss of Access and possible System Outage
Affected Domain

z/OS using zHPF and  DS8900F below R9.0 SP3 - 89.3.6.0, and 32Gb Host Adapters 
Description

On DS8900F systems, an irregular zHPF Format Write chain is not handled correctly by 32Gb Host Adapters.
This may lead to multiple Host Adapters being fenced, whether or not the FICON paths are running at 32Gb/S speed.
 
If the DS8900F system contains only 32Gb Host Adapters, or has path groups using only 32Gb Host Adapters, this may lead to a loss of access.  
This problem has been reported on z/OS systems running sort utilities (e.g. DFSORT or SyncSort).
 
Mitigation 

Until the fix can be loaded, disable ZHPF Format Write. 
 
    Disable zHPF Format Write (i.e. zHPF feature bit 8) for all access methods  
    https://www.ibm.com/support/pages/apar/OA55583 
     
Fix

Install R9.0 SP3 - 89.3.6.0 or later code bundle
  
Reference ID:
349936

[{"Line of Business":{"code":"LOB26","label":"Storage"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSHGBU","label":"IBM DS8900F"},"ARM Category":[{"code":"a8m0z000000bqa5AAA","label":"09 - Host Attachment"}],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)"}]

Document Information

Modified date:
24 May 2022

UID

ibm16326525

Page Feedback