man: describe zfs-rewrite method and properties

[robn]

[Sponsors: Klara, Inc., Wasabi Technology, Inc.]

Motivation and Context

We've heard anecdotes that suggest some confusion/surprise/disappointment that a changed recordsize is not applied during rewrite. Until such time as we actually can do that, we can at least explicitly mention it at something that doesn't work.

Description

Another paragraph in the NOTES part of zfs-rewrite(8), describing vaguely what rewrite is, and from there, specific property changes that are and aren't applied.

How Has This Been Tested?

Manpage change, so just mancheck.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Quality assurance (non-breaking change which makes the code more robust against bugs)
• Breaking change (fix or feature that would cause existing functionality to change)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.