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The Backup Administrator installs or upgrades the File System Agent and the Microsoft SQL Server Agent on a Windows SQL Server. The PowerProtect File System Agent includes the block-based backup driver ( nsrbbb.sys ). The nsrbbb.sys driver intercepts write I/O from SQL Server and exhibits elevated logical write waits. The interception adds approximately 62ms of overhead per I/O operation. SQL job processing times nearly double after the driver installation and continue to slowly increase over the course of days. On servers that are also running the Epic System software, the "Extract, Transform, Load" (ETL) job times also increase over the course of days.
In heavy I/O SQL Server environments, the driver's fixed 62ms overhead per I/O causes significant cumulative latency. The SQL logical write waits increase because every write passes through the driver and the latency compounds under heavy workloads. The symptoms mimic storage array performance issues, which may delay root cause identification.
The issue is being investigated and will be resolved in a future release of PowerProtect. Workaround - Disable the BBB Driver: Validate there are no active PPDM backups on the affected Windows Server. On the affected Windows SQL Server, open a command prompt as administrator. Stop the nsrbbb driver: sc stop nsrbbb Disable the driver from starting automatically: sc config nsrbbb start= disabled Confirm SQL write latency returns to normal levels. After disabling the driver, backups use File Based Backup (FBB) instead of Block Based Backup (BBB) workflow. If there are any further questions, contact Dell Support for assistance and reference this KB article.
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