clear zpool history

[leelists]

Hi,

I have some really old zfs pools (upgraded from 0.7.0) which zpool history is huge , is there a way to clear it's content ?
If not it would be great if there exists a way to clear it

Thanks for reading ;-)

[gesrtewrtwr]

To quote one of the best AIs / LLMs (another big one says the same thing) (lmarena.ai):

The zpool history is not a simple log file stored in /var/log. It is an integral, on-disk part of the pool's metadata, stored in the Meta-Object Set (MOS). It's designed to be a permanent, append-only, transactional record of every administrative action that has ever modified the pool's state.

This design has several key purposes:

1. Auditing and Forensics: It provides an immutable record of who (which user) did what (which command) and when. This is invaluable for debugging issues or for security audits.
2. Integrity: The history is part of the same transactional system as all other pool changes. This ensures that the record of a change is committed at the same time as the change itself, preventing inconsistencies.
3. Debugging: ZFS developers can use this history to understand the sequence of events that may have led to a bug or a corrupted state.

Because it's a core part of the pool's metadata, there is no command like zpool history --clear or zpool history --prune. Allowing this would violate the design principle of having an immutable audit trail.

To actually get a clean history going forward: create a new pool and migrate via snapshots and send/receive. Example outline: ...