On 08/02/2021 16:25, Ian Jackson wrote: > Olaf Hering writes ("[PATCH v20210111 08/39] xl: fix description of migrate > --debug"): >> xl migrate --debug used to track every pfn in every batch of pages. >> But these times are gone. Adjust the help text to tell what --debug >> is supposed to do today. > ... >> -Display huge (!) amount of debug information during the migration process. >> +Verify transferred domU page data. All memory will be transferred one more >> +time to the destination host while the domU is paused, and compared with >> +the result of the inital transfer while the domU was still running. > Andy, as our expert on migration, can you confirm whether this is > accurate ? > > Docs (including usage message) so > > Release-Acked-by: Ian Jackson <i...@xenproject.org>
Yeah - I totally changed what --debug did in migration v2, and this is stale. The legacy behaviour was unhelpful on any non-trivial guest. It is possibly worth noting that you typically do see changed data when using --debug, because of how the front/back pairs work. This was a bit of a curveball during development. ~Andrew