Error trying to read tape

Products

CA 1 Flexible Storage TLMS Tape Management

Issue/Introduction

Currently, I am receiving the following error when trying to read a few tapes:

IEF233A M 0226,111111,,DT#EABC,COPY3,DRY.IBM.PROD.DATA.T0000
IEC149I 813-04,IFG0195H,DT#EABC,COPY3,SORTIN,0126,111111, 531
DRY.IBM.PROD.DATA.T0000,
LBL=00000000000000000

Environment

CA 1 Tape Management / CA-TLMS

Cause

The Dataset in JCL doesn't match the IBM standard labels on the tape.

Resolution

The way a physical volume and IBM VTS volume differ is in the way the data is deleted after it is scratched. With the old physical volumes, you could turn the volume to a non-scratch within either the CA 1 or TLMS tape management and if the volume had not been reused, you could read the data back in.

In an IBM VTS a scratch command from either CA Tape Management or OAM will set the scratch indicator on within the Tape Library Manager. The data/volume will remain intact until the IBM VTS option EXPIRE-HOLD is met. If the option is set to 24 hours, the data from the volume will be deleted and a new IBM Standard label will be written. If you try and read the volume, you will most likely see a S813/613 abend as the dataset in the JCL doesn’t match the IBM HDR1/HDR2. You can run the following JCL to dump the label of the tape:

//STEP1 EXEC PGM=IEBGENER

//SYSPRINT DD SYSOUT=*

//SYSOUT DD SYSOUT=*

//SYSIN DD DUMMY

//SYSUT1 DD DSN=WHERE.IS.MY.DATA,

// DISP=SHR,LABEL=(1,BLP,EXPDT=98000),

// UNIT=VTAPE,DCB=(LRECL=80,BLKSIZE=80,RECFM=FB),VOL=SER=111111

//SYSUT2 DD SYSOUT=*

If the SYSUT2 has the following, a new SL label has been written and there is very little chance in the recovery of the data from that tape:

IEBGENER shows:

VOL111111

HDR10000000000000000000000000000000000000000000000000000000000000000000000000000

*

More information on the IBM EXPIRE HOLD parm:

EXPIRE HOLD and low on scratch tapes in a TS7700. The EXPIRE HOLD option is used to ensure that a logical volume that is sent to the SCRATCH pool cannot be reused or deleted before the grace period that is specified as the EXPIRE time has passed. This fact can sometimes create a problem where the library might run out of available volumes to satisfy mount requests to write new data. If the EXPIRE time has been set too long and there are not enough logical volumes being released to keep a healthy level of SCRATCH volumes available, it might be necessary to reduce the EXPIRE time. However, this change affects only new volumes that are going into the SCRATCH pool. The existing volumes in the pool continue to be held until the original EXPIRE time has passed. However, if EXPIRE HOLD is cleared, these volumes can then be added to the candidate list for SCRATCH mounts. Therefore, clearing the EXPIRE HOLD option immediately helps to alleviate the low on scratch condition, but it no longer protects data that has inadvertently been sent to SCRATCH. The recovery of user data on volumes in the SCRATCH pool might no longer be certain.

10.3.2 EXPIRE HOLD and cache utilization in 7700. When the EXPIRE HOLD option is enabled, the cache in a TS7700 is used up in part by holding data from logical volumes that have been sent to the SCRATCH pool. In addition to the risk of running out of logical volumes to mount, there is a risk of running out of cache in a TS7700 when AUTOREMOVAL is not enabled. Again, EXPIRE time should be considered, and if a TS7700 Is consistently running high on cache utilization, adjust this EXPIRE time. In this case, the clearing of the EXPIRE HOLD setting does not immediately alleviate the high cache utilization condition. The effect of disabling the EXPIRE HOLD from the cache perspective is to enable volumes in the SCRATCH pool to begin entering the candidate list for expire delete processing. Once per hour, a task runs in the library that processes some number of volumes from this list, and reduces cache utilization by deleting the expired volumes from cache. The number of volumes that are deleted per hour is by default 1000. The number of volumes that are moved to this candidate list is customizable (1000 - 2000), and is controlled by using the LI REQ,composite-library,SETTING,DELEXP,COUNT,value command. For more information refer to the IBM documentation.

The EXPIRE time is the grace period that enables the recovery of the data in the case of procedural error. Careful consideration needs to be made to ensure that this value is long enough to allow for such errors to be detected, and the data recovered, before the DELETE EXPIRE process removes the logical volume permanently