[LUDOC-497] Snapshot tools may fail when #targets > MaxStartups in sshd_config

• Type: Question/Request
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.13.0 Manual
• Labels: snapshots zfs
• Environment: Lustre 2.12.7, CentOS 7.9, zfs 0.8.5
• Assignee: Lustre Manual Triage
• Reporter: Nathan Crawford

Description

When using ssh as the remote shell for zfs-based lustre snapshots, servers with large numbers of targets may fail to create snapshots on all relevant zfs datasets. A new ssh connection is attempted for each target, and when the total reaches the default maximum number of concurrent unauthenticated connections (10), there is a chance the next connection will be killed.

The solution suggested for LU-9368 works for me: make sure that the MaxStartups value in /etc/ssh/sshd_config is at larger than the number of targets on the server.

Can a note about this appear in the documentation or man pages? It took me an embarrassingly long time to track it down.