Reason for View EAS task issuing SAREA03S with error code 02D6 message
Article ID: 268815
Updated On:
Products
Issue/Introduction
- At the time the problem occurred we had 8 tape drive devices available.
- Error received was:
SAREA03S Dynamic allocation error for SAREAS (WTREAS1/XXXX)
SAREA03S error=02D6, info=0000, UNIT=*CATLG*, DSN=your.viewdb.SARTAPE.T*******
- With the EAS task criteria defined below...
COMM = XCF
DFQIDLE = 0
MAXIDLE = 45
MINIDLE = 15
MOUNT = D
EASTNAME = CEAS
NBUF = 64
NREAD = 4
NREQ = 200
NTHREADS = 16
TYPE = PRIMARY
Q1. Please let us know if NTHREADS should be set to the same number as available devices to avoid such error.
Q2. And also confirm whether this error came up because lack of available tape drives when requesting surpassing the maximum number at a given moment.
Environment
View, 14.0, EAS, NTHREADS, SAREA03S, 02D6
Cause
The problem is caused by them setting NTHREADS=12 and only having 8 tape devices available on the system.
NTHREADS should match the number of dedicated tape drives on the system, unless the drives are shared.
If shared, it's possible that EAS will bump heads with other external jobs on busy days. It's hit or miss with shared tape drives.
Resolution
The IBM Interpreting error reason codes from DYNALLOCr code manual documents the 02D6 as follows:
02D6
Meaning: Allocation failed because there were no available offline devices within the specified esoteric, so there are no eligible devices to be brought online by Recovery Allocation processing to satisfy the request.
System programmer action: Verify that the volume serial specified is valid, and that it is online in the specified esoteric. Correct the volume serial or unit information if necessary.
Considering the above,
Q1. Please let us know if NTHREADS should be set to the same number as available devices to avoid such error.
Answer 1: Yes.
Q2. And also confirm whether this error came up because lack of available tape drives when requesting surpassing the maximum number at a given moment.
Answer 2: Yes.
Additional Information
From the View 14.0 documentation:
SAREA03S
Last Updated March 2, 2023
DYNAMIC ALLOCATION ERROR FOR SAREAS (jobname/sysid) ERROR=xxxx, INFO=xxxx, DSN=dsname
Reason:
Dynamic allocation failed for the tape specified by dsname. The hexadecimal error and information codes are provided.
Action:
None. The tape cannot be used. Processing continues.
NTHREADS=n
The number of tape processing threads (drives) for the primary or only server. This number can be lowered or raised dynamically, but it can never exceed the value that is specified on this parameter. (The value specified cannot exceed the value specified for NTHREADS when the task was started.)
Each tape is accessed by an individual subtask (thread) in the EAS address space. NTHREADS indicates the maximum number of tapes that can be accessed at the same time. In the case of physical tape, there is normally a limited number of tape devices. You might need some of those tape devices for jobs that you run, and you can dedicate some devices for EAS. With VTAPE, a lot more tape devices are normally available so NTHREADS can be higher. When all threads are busy, a request for a new tape has to wait for a thread to reach MINIDLE for it to be available.
This parameter is redundant for a secondary server. Each tape processing thread can allocate one tape drive; therefore, specify the maximum number of tape drives that you want to be available to the server.
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