Operational Defect Database
BugZero found this defect 3948 days ago.
Data sources
All data on this page is proprietary to BugZero® or gathered from public sources
Veeam | kb1795
Zlib decompression error: [-3] | Failed to decompress LZ4 block
Last update date:
5/3/2023
Affected products:
Veeam Backup & Replication
Affected releases:
8.0
Fixed releases:
No fixed releases provided.
Description:
Challenge
A Backup Job or Restore fails with either of the following errors: Zlib decompression error: [-3]. or Failed to decompress LZ4 block:
Cause
When the software reads from a an existing restore point it performs error detection using Cyclic Redundancy Checks (CRC) to validate the data. The error messages list in this article occur when a CRC fails. The error indicates that one or more blocks in the restore point are corrupted.
Solution
Restoring Missing Production Data If the failing restore was being performed to restore missing production data, please create a Veeam Support Case. Veeam Support has tools that may be able to recover data from a restore point if it is not fully damaged.
More Information
Veeam Backup & Replication's Data Movers use network traffic verification when transfering data between proxies and repositories to detect corruption which might occur. Therefore decompression errors are unlikely to be caused by a malfunctioning NIC, router, or other network device if the repository server is using a local disk (Windows Repository | Linux Repository). For Windows Repositories the event log on the repository server may contain Disk Event 7: “The device… has a bad block.” If so, run CHKDSK /F or /R. If additional bad block events occur after running CHKDSK, check the SMART status and consider replacing the disk. When backing up to a CIFS share, NFS share, or iSCSI volume, malfunctioning network hardware is a possible cause of corrupted backup files, because Veeam's network traffic verification cannot verify data sent to those destinations. Enabling Storage-level corruption guard will cause the backup/backup copy job to perform automatic checks to proactively detect CRC failures due to corrupted backup files. If disk failure is a suspected cause of restore point corruption when using a Network Attached Storage device, contact the storage vendor to determine what diagnostics are available. What is the 3-2-1-1-0 backup rule?
