Challenge
A Backup Copy or Replication job that utilizes WAN Accelerator fails with any of the following errors:
Error: Source WAN accelerator error: Failed to decompress LZ4 block: Bad crc
Error: Source WAN accelerator error: Failed to decompress LZ4 block: Incorrect decompression result or length
Error: Source WAN accelerator error: Client error: Zlib decompression error: [-3].
Cause
These errors may occur because the internal CRC check either failed for a source restore point or data within the WAN Accelerator Cache. This article documents how to resolve the issue when it occurs within that cache.
Solution
Issue Isolation
To begin the investigation, isolate whether the issue is related to the WAN Accelerator Cache or the Restore Points.
Edit the job that is failing.
Switch to the Data Transfer section of the job configuration.
Change the job to use 'Direct' instead of 'Through built-in WAN accelerators'.
Run the Job, and observe the outcome.
More Information
The Windows event log on the repository server may contain Disk Event 7: “The device… has a bad block.” If so, run CHKDSK /F or /R. A small number of bad blocks are normal on most storage devices. If additional bad block events occur after running CHKDSK, check the SMART status and consider replacing the disk. If using a Network Attached Storage device, contact your storage vendor to determine what diagnostics are available.
For more information, review: Veeam KB1795.
