Troubleshooting invalid data error messages

You should check that you configured SnapValidator correctly before investigating other reasons when SnapValidator checks return error messages.

Considerations

Data ONTAP will send invalid data error messages if SnapValidator detects problems in the following areas:

Checksum Error
Bad Block Number
Bad Magic Number
No Valid Block Size
Invalid Length for Log Write
Zero Data
Ones Data
Write length is not aligned to a valid block size
Write offset is not aligned to a valid block size

Steps

If you receive a message indicating that SnapValidator detected or rejected invalid data, verify the following:
- You enabled the SnapValidator checks on the volumes that contain your data files.
- You set the SnapValidator checks correctly. For example, if you set the svo_allow_rman volume option to on, then make sure that the volume contains Oracle Recovery Manager (RMAN) backup data. If you store RMAN data in a volume that does not have this option set, then you might receive an error message indicating that SnapValidator detected invalid data.
If the SnapValidator options on the storage system are correctly set but you still receive the above errors, check for the following problems:
- Your host is writing invalid data to the storage system. Consult your database administrator to check Oracle configuration on the host.
- You might have a problem with network connectivity or configuration. Consult your system administrator to check the network path between your host and storage system.
If you receive a message indicating that a write operation to a LUN failed, verify that you set the correct disk offset on the LUN. Identify the disk offset and reset the offset defined for the LUN by using the procedures you used when you enabled SnapValidator checks on LUNs.
SnapValidator displays two messages similar to the following when write operations to a LUN fail:
- The first message is generated by SnapValidator and indicates that the storage system detected invalid data. The error message does not show the full path to the LUN. The following is an example error message:
```
Thu May 20 08:57:08 GMT [fas3050: wafl.svo.checkFailed:error]: 
SnapValidator: Validation error Bad Block Number:: v:9r2 
vol:dbtest inode:98 length:512 Offset: 1298432
```
- The second error message is a scsitarget.write error, which shows the full path to the LUN. The following is an example error message that indicates a write to a specific LUN failed:
```
Thu May 20 14:19:00 GMT [fas940: scsitarget.write.failure:error]: Write to LUN /vol/dbtest/oracle_lun1 failed (5)
```

Parent topic: Database protection using SnapValidator

Related tasks

Enabling SnapValidator checks on LUNs

Enabling SnapValidator checks on volumes