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Commvault · Troubleshooting guide

Commvault Troubleshooting: Jobs Waiting on Mount Paths, Offline Clients and Media Agent Pressure

How to clear stuck Commvault data protection jobs: library and mount-path waits, client connectivity on port 8403, and media agent bottlenecks.

Published August 28, 2026 · RCW IT Training

Jobs that will not run

Job pending: 'Waiting for mount path' or 'waiting for media'

The storage policy needs a free mount path on a library or drive. In the CommCell Console check that drives are online and the media agent sees the library. For disk libraries verify the mount path folder exists, is mounted, and has space - a silently unmounted NFS or CIFS path is the classic cause. Bring the mount path online or add another, and check whether other jobs are holding all streams.

Aux copy or DASH copy stuck for hours

Check the source media agent's dedupe database health and the network path to the target; throttling rules and maximum-streams settings also cap throughput. Review the CVD logs on both media agents and confirm the target library is not pending, as in the previous case.

Clients and media agents

Client shows offline although the server is up

Commvault talks on port 8403 plus a dynamic range. Test with telnet client 8403 in both directions, check the client service and local firewall, and verify name resolution both ways - CommCell name versus DNS. After IP changes update hosts entries or re-register, and use cvping from the media agent to prove the control path.

Backups slow across the board on one media agent

Inspect the media agent: dedupe engine memory, disk queue depth on the dedupe store, and network saturation. A full dedupe database volume stalls everything - alert on that volume specifically. Also review data path parallelism: too many streams to one target can thrash; right-size per vendor guidance.

Key takeaway: 'Waiting for mount path' is a library and space problem, offline clients are almost always a 8403 or DNS problem, and a sick media agent dedupe volume slows the whole CommCell.