Re: ext4 - 52.2% non-contiguous

[Miles Bader <miles@gnu.org>]

"Todd A. Jacobs" <nospam@codegnome.org> writes:
> by default, rsync copies a file in small chunks, so copying an entire
> filesystem to a drive that is actively in use could certainly cause
> fragmentation.

Actually shouldn't ext4 do _better_ (than ext3 etc) in such a case,
since it does allocate-on-write, allowing it to allocate contiguous
storage despite the user writes being small?

> Really, the main reasons to use rsync are:
>
>     - to enable resume on really large files (e.g. an entire filesystem
>       tarred as home.tar.gz)
>     - to transfer file deltas rather than entire files

While there's some truth to that, I think people often like to use rsync
even for virgin copies simply because it has a very convenient syntax,
and it's simpler to use one tool for all cases (new copies, "update"
copies, resumes, etc) and not have to worry about micro-optimizing each
individual case.

-Miles

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