[LU-6051] "lfs_migrate" improvements

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.11.0, Lustre 2.10.4
• Labels: easy
• Severity: 3
• Assignee: Steve Guminski (Inactive)
• Reporter: Andreas Dilger

Description

There are a couple of improvements to make to the lfs_migrate script:

• pass all of the "lfs setstripe" options through to "lfs migrate" when calling "lfs_migrate" (they do not overlap), so it would be possible to just strip out existing lfs_migrate options and pass the rest to "lfs migrate"
• the man page should be updated to say it is safe to use on in-use files for 2.5+ MDTs (when the lfs migrate command was in place and working correctly)
• the man page should be split into a separate lfs-migrate.1 man page with more description and examples (per LU-4315)
• the hard-link migration doesn't need to do anything special if "lfs migrate" works, and if it fails then "lfs path2fid" and "lfs fid2path" (or "lfs path2fid --parents") can be used to generate the list of links to a file and then hard-link

Issue Links

• is related to: LU-11621 Add copy_file_range() API and use it for lfs migrate and mirror resync
• is related to: LU-8235 Add pool awareness to lfs_migrate
• is related to: LU-4315 split lfs.1 and lctl.8 man pages into one page per subcommand
• is related to: LU-8207 Add auto-stripe option to lfs_migrate
• is related to: LU-9629 lfs migrate does not work as a non-root user