git-annex/doc/todo/fast_migrate.mdwn

Moved this comment to todo list --[[Joey]]

[[!comment format=mdwn
 username="https://www.google.com/accounts/o8/id?id=AItOawnfM7ZF0Q5U9k1LljyDXH37cuXU5Gx6gtM"
 nickname="A"
 subject="fast migrate"
 date="2014-07-05T08:21:20Z"
 content="""
dear Joey and everybody else,
 some time ago I used \"git annex migrate\" to bring all my repositories up-to-date; after that I found (to my dismay) that some keys are SHA256, some others are SHA256E, so my data is not really deduplicated  ; now, it would possible to migrate from SHAnnnE to SHAnnn (and vice versa) very fast... but currently AFAICS git-annex recomputes the whole checksum, and this (on my USB2.0 old disks) takes forever; may somebody please implement a fast migration?
"""]]

> Certianly doable, for $hashE to $hash. Probably about an hour's work.
> --[[Joey]]

>> [[done]] --[[Joey]]
promote comment to todo 2014-07-10 20:27:12 +00:00			`Moved this comment to todo list --[[Joey]]`

Added a comment: fast migrate 2014-07-05 08:21:21 +00:00			`[[!comment format=mdwn`
			`username="https://www.google.com/accounts/o8/id?id=AItOawnfM7ZF0Q5U9k1LljyDXH37cuXU5Gx6gtM"`
			`nickname="A"`
			`subject="fast migrate"`
			`date="2014-07-05T08:21:20Z"`
			`content="""`
			`dear Joey and everybody else,`
			`some time ago I used \"git annex migrate\" to bring all my repositories up-to-date; after that I found (to my dismay) that some keys are SHA256, some others are SHA256E, so my data is not really deduplicated ; now, it would possible to migrate from SHAnnnE to SHAnnn (and vice versa) very fast... but currently AFAICS git-annex recomputes the whole checksum, and this (on my USB2.0 old disks) takes forever; may somebody please implement a fast migration?`
			`"""]]`
promote comment to todo 2014-07-10 20:27:12 +00:00
			`> Certianly doable, for $hashE to $hash. Probably about an hour's work.`
			`> --[[Joey]]`
migrate: Avoid re-checksumming when migrating from hashE to hash backend. 2014-07-10 21:06:04 +00:00
			`>> [[done]] --[[Joey]]`