I'm taking over the content here as well.
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)
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
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)