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Potential exposure to job aborts in z/OS environment with zHPF enabled running on a DS8870 with R7.1

Flash (Alert)


Abstract

z/OS clients with zHPF enabled running on a DS8870 with R7.1 bundles below 87.10.102.0 are exposed to job aborts due to Channel Errors (IOS071I START PENDING)

Content

The job aborts due to Channel Errors (IOS071I START PENDING) are caused by an internal condition of the DS8870 when zHPF is enabled.
Based on the number of transferred bytes per track the calculation for the amount of SMBs (sequential memory buffer) the DS8870 needs to allocate for transferring data over the channel may be wrong.
This wrong calculation leads to a code exception or an I/O hang in the DS8870 which may result in job aborts and IOS071I START PENDING messages.

The issue was introduced in the R7.1 GA bundle 87.10.87.0 and fixed in the bundles identified in the Resolution section below.

Exposed Microcode bundles:
R7.1: all Microcode bundles below 87.10.102.0 R7.1 SP3, multiple field occurrences observed, all on bundle 87.10.91.1

Mitigation:

Disable zHPF until a service window can be scheduled to update DS8870 firmware to a bundle containing the fix.

Resolution :

A DS8870 microcode build to fix this issue has been made available in Bundle 87.0.102.0 or higher.

87.10.102.0 R7.1 SP3
87.20.220.0 R7.2 GA

For those customers upgrading code from R7.0 to R7.1 and running zHPF the minimum recommended microcode level is 87.10.102.0 (R7.1 SP3)

Document information

More support for: DS8870

Version: Version Independent

Operating system(s): z/OS

Software edition: N/A

Reference #: S1004538

Modified date: 29 December 2014


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