Abstract
Running with zHPF enabled on a IBM System Storage
DS8000®, can lead to host hangs, looping jobs and recursive errors on
the IBM System Storage DS8000®system.
Content
IBM System Storage DS8000® when running in a z/OS environment with zHPF enabled can result in:
1. In certain cases customers have experienced hosts to become unresponsive after sense is off-loaded from the DS8000 with zHPF enabled. This was seen only with SyncSort MFX 2.1. SyncSort is recommending APAR TY01136 for this issue. Until the APAR is applied, SyncSort is recommending the customer disable zHPF for SyncSort MFX 2.1 (use parameter LBPZHPF to bypass zHPF usage for an individual job and installation option SCOS=(204) to turn off all zHPF usage for SyncSort).
Licensed SyncSort MFX customers can reference Knowledge Base Article 46965 for more information about PTF TY01136.
2. In other situations customers have encountered repeating warmstarts, after software issues a zHPF Multi-Track Read command when the tracks are configured with more than 55 records per track, and there are multiple tracks to transfer. This results in the DS8000 incorrectly surfacing a Microcode Logic Error (MLE) which requires a warmstart to clear. This has been seen only with SyncSort MFX 2.1 software, although other software implementing similar chains would be exposed. After the MLE, software re-drives the command chain, resulting in repetitive MLEs that can result in system access loss. There is a DS8000 microcode fix in test scheduled for a near term release. In the interim, IBM is recommending that customers disable zHPF for SyncSort MFX 2.1 until the DS8000 fix is applied.
Examples of errors seen:
Message to Operator (WTO) notices WER529A and WER999A.
Missing Channel End and/or Missing Device End.
Host hangs/unresponsiveness.
DS8000 Microcode bundles containing the fix
DS8700 76.31.159.0
DS8800 86.31.184.0
DS8870 87.41.42.0
87.51.23.0
1. In certain cases customers have experienced hosts to become unresponsive after sense is off-loaded from the DS8000 with zHPF enabled. This was seen only with SyncSort MFX 2.1. SyncSort is recommending APAR TY01136 for this issue. Until the APAR is applied, SyncSort is recommending the customer disable zHPF for SyncSort MFX 2.1 (use parameter LBPZHPF to bypass zHPF usage for an individual job and installation option SCOS=(204) to turn off all zHPF usage for SyncSort).
Licensed SyncSort MFX customers can reference Knowledge Base Article 46965 for more information about PTF TY01136.
2. In other situations customers have encountered repeating warmstarts, after software issues a zHPF Multi-Track Read command when the tracks are configured with more than 55 records per track, and there are multiple tracks to transfer. This results in the DS8000 incorrectly surfacing a Microcode Logic Error (MLE) which requires a warmstart to clear. This has been seen only with SyncSort MFX 2.1 software, although other software implementing similar chains would be exposed. After the MLE, software re-drives the command chain, resulting in repetitive MLEs that can result in system access loss. There is a DS8000 microcode fix in test scheduled for a near term release. In the interim, IBM is recommending that customers disable zHPF for SyncSort MFX 2.1 until the DS8000 fix is applied.
Examples of errors seen:
Message to Operator (WTO) notices WER529A and WER999A.
Missing Channel End and/or Missing Device End.
Host hangs/unresponsiveness.
DS8000 Microcode bundles containing the fix
DS8700 76.31.159.0
DS8800 86.31.184.0
DS8870 87.41.42.0
87.51.23.0
1 comment:
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