What is the maximum number of backups that can be running per Avamar storage node in order for HFS check to initiate successfully?

The HFS (Hardware File System) check is a critical integrity check that runs during the daily maintenance window. To ensure a consistent and accurate scan of the data stripes on the storage nodes, the system must be in a relatively quiescent state. The HFS check process will not initiate if more than two backup or restore sessions are actively running on any single storage node in the Avamar grid. This threshold prevents active I/O operations from interfering with the integrity check.

A. The system allows for a small amount of activity; a single backup is permitted, so the threshold is higher than 1.
C. Three active backups on a node are considered too much activity for the HFS check to start safely, so it will wait.
D. Four active backups would present a significant workload on a node, preventing the HFS check from initiating.

1. Dell Avamar Administration Guide, Version 19.9, Page 141, "HFS check". The guide explicitly states, "The HFS check does not start if more than two backup/restore sessions are running on any data node."

2. Dell Avamar System Health Check and Monitoring Guide, Section "Daily Maintenance Tasks". This document details the preconditions for maintenance jobs, noting that hfscheck has a prerequisite check for active sessions and will pause if the count exceeds two per node.