VTAPE message : SVT1D0908I SVTS Cache Shortage - 097% Utilization Reached

Products

• Vtape Virtual Tape System

Issue/Introduction

The production CA Vtape has reached 97% of threshold value and continuous alerts are coming. could you please 

SVT1D0908I SVTS Cache Shortage - 097% Utilization Reached                     

 

Environment

VTape R12.6

Cause

Root cause of the problem was the G=1 queue was held.

Once this was corrected, cache was seen to be filling up - not clearing quickly.

Resolution

To release the G=1 queue:

/SVT1 SET BACK=-R,G=1,SG=* - to allow the data to be offloaded from cache to BACKSTORE tapes.

Setting the MAXDRIVES to 6 allowed the BACKSTORE to run more quickly to offload data and empty the cache.

/SVT1 SET MAXDRIVES=6

Additional Information

Viewing the VTape log shows RECALLING and BACKSTORE was occurring but it was slow due to the Cache being full.
Once the MAXTAPES setting was increased to 6, the Cache was cleared much faster.