What does ADF SSIS Error "Disk Full Exception Caught" mean

The "Disk Full Exception Caught" error in the Azure Data Factory SSIS Integration Runtime (IR) generally indicates that the disk storage on the VM hosting your SSIS IR has been exhausted. This can happen when the temporary storage provided by the VM SKU (in your case, the D8_v3 with 200 GB) is filled up, which might be used by SSIS packages for temp files, logs, or database-related activities.

What Does the Error Mean?

1. Temporary Storage Usage: Azure VM SKUs like D8_v3 come with limited temporary storage (200 GB in this case). SSIS operations like data movement, lookups, sorting, and logging can consume temporary disk space. If the SSIS IR runs out of space, it throws a "Disk Full" exception.
2. SSIS Package Activities: If your SSIS packages are dealing with large datasets, they may be consuming significant disk space for temporary files, intermediate data processing, or logs.
3. Temporary Database Storage: SSIS may use disk storage for temporary tables, caching, or staging data. If you're working with large datasets, the disk space could fill up quickly.

Troubleshooting Steps

1. Monitor Temporary Disk Usage:
   • Check the disk space on your IR VMs by logging into the VM or using Azure monitoring tools to track the storage consumption of the D8_v3 VM.
   • Look for temporary files or logs generated by SSIS packages that might be taking up space.
2. Review SSIS Package Design:
   • Optimize Data Flow: Look at data flow operations such as sorting, lookups, or caching that could be consuming temporary disk space. Consider redesigning packages to reduce the disk space requirements.
   • Manage Logs: Ensure that the logging level of your SSIS packages isn't set too high (like verbose), which could generate large log files.
   • Clean Up Temporary Files: Ensure that your SSIS packages clean up any temporary files they create.
3. Scale VM or Attach Additional Disks:
   • Consider scaling up your SSIS IR to a larger SKU with more storage or attaching additional managed disks if your workload requires more disk space.
   • Use Azure Blob Storage for staging or caching large datasets instead of relying on the temporary disk.
4. Check Database Storage:
   • If your SSIS packages interact with databases, confirm if database storage (such as TempDB) might be contributing to the problem. This could occur if your data processing requires significant temporary table space or caching.
5. Logs and Diagnostic Settings:
   • Continue reviewing the ADFSSISIntegrationRuntimeLogs for more granular information on the exact packages or processes that might be consuming excessive disk space.
   • Set up custom diagnostic logging or alerts to notify you when disk space usage approaches a critical threshold.

Let me know if you need any additional troubleshooting assistance or details!