Re: git clone questions relating to cpio

["Reece Dunn" <msclrhd@googlemail.com>]

On 01/10/2007, Johan Herland <johan@herland.net> wrote:
> On Monday 01 October 2007, Reece Dunn wrote:
> > Hi,
> >
> > I am running a Linux From Scratch 6.2 system that does not have cpio
> > installed on it. This means that I can't clone a local repository
> > unless I install cpio. Is it possible to use a fallback method if cpio
> > is not present, as there is no NO_CPIO option on make like there is
> > for OpenSSH, cURL and expat?
>
> Using "file://" when specifying the source repo will force git-clone to use
> the git protocol, instead of doing a copy/hardlink.
>
> I.e. change "git clone foo bar" to "git clone file://foo bar" in order to
> prevent git-clone from calling cpio.

Thanks for the tip.

> However, grepping for cpio in the git source tree reveals a couple of uses
> in git-merge, so you might bump into problems there...

Looks like I'll need to install cpio, then (also allowing me to take
advantage of the fast local clones via hardlinks).

Do you know if cpio is listed anywhere in required dependencies?

> > Also, I have an external USB hardrive that is mounted onto the virtual
> > filesystem. Will clones from the USB harddrive (or a USB flash drive
> > that is mounted) result in a copy being performed, not a hardlink?
>
> Hardlinks are impossible across filesystems. If you're cloning to a
> different filesystem git will _have_ to make a full copy.

Exactly. I was asking this to clarify cpio (and therefore git)
behaviour in this situation.

> > Ideally, the hard linking for local clones should be optional.
>
> <quote src="git-clone(1)">...</quote>

Indeed, they are. Thanks for the info.

> And as I said above, you can use "file://" to force the "git aware"
> transport mechanism, which bypasses the whole local copy/hardlink issue
> entirely.

Sure.

> > What if I want to move a repository because, for example, I have imported
> > a CVS repository and now want to push it to a new bare repository?
>
> Even if you were to use hardlinks, cloning a repo followed by deleting the
> original will be safe (as long as you don't supply '--shared' to
> git-clone). That's the beauty of hardlinks.

That is good to know.

> I also think it's fairly safe to just 'mv' the whole repository to its new
> location.

This also works, as long as you are not moving between a bare and
standard repository.

> Have fun! :)

Will do :)

Thanks,
- Reece