[mirror-admin] IITM mirror still not on list..

[Matt Domsch]

On Sun, May 18, 2008 at 08:29:32AM +0530, susmit shannigrahi wrote:
> Respected Sir, first let me extend many thanks for making this mirror
> available to public.

let me add my thanks as well.
 
> >due to space constraints, older
> > releases and updates are available only for local users. correct me if i
> > am wrong, but i fail to see any logic in carrying multiple copies of all
> > packages - once in the dvd image (and once more in the cd image if one
> > carries that), once in the fedora/os directory and once more in the
> > everything/os directory. there must be a saner way to do this?

For the record, the tree is hardlinked using hardlink++ on the
server.  You need to use rsync -H to preserve hardlinks when
downloading.  This means the files:

pub/fedora/linux/releases/9/
./Fedora/i386/os/Packages/emacs-22.2-4.fc9.i386.rpm
./Everything/i386/os/Packages/emacs-22.2-4.fc9.i386.rpm

are hardlinked, so only downloaded once and only take up disk space
once; furthermore, if you happen to be carrying the
pub/fedora/linux/development/ tree, these files are present and
hardlinked there as well.  (Yes, calling 'stat' on this file shows
Links: 3 and the same inode # for all three instances.)


This is why we recommend syncing the whole tree at pub/fedora/ (the
fedora-enchilada rsync module) in one shot, excluding whatever you
like.  The hardlinks are there to help, but in order to benefit, all
the hardlinked files (that you don't exclude) need to be seen by the
same rsync run.


I do fully agree that it is unfortunate that packages appear on disk multiple
times, once as plain RPMs, once inside a DVD ISO, and once inside a CD
ISO.  However, because Fedora release-engineering does not publish the
Everything tree as DVD ISOs, and mirrors are still expected to carry the
Everything tree as RPMs, which as I note above, are hardlinked;
loopback mounting the DVD ISOs as the Fedora tree is possible, but
unnecessary if carrying the Everything tree; Everything is a superset
of the Fedora tree, so the Fedora tree is hardlinked to it, thus
taking no additional disk space (modulo the extra directory entries).

Not all mirrors carry the DVD and CD ISO images.  They are in the iso/
directory exactly to make them easy to exclude, should you wish to.

> I believe the DVD iso, Everything/os and updates are all that needed
> for users.
> 
> This is because yum points to everything/os directory for installation
> of new packages and to updates for updatation.

Correct.

> And about carrying DVD iso it depend on the bandwidth et al, but not
> carrying this does not affect yum anyway.

Correct.

Yes, the whole fedora-enchilada and fedora-epel file system together
consumes 850GB.  A good portion of that is Fedora {Core,Extras} 6 and
earlier, which will be moved to archives.fedoraproject.org shortly.
The Fedora 9 release, including everything, is about 114GB; this can
be trimmed on each mirror by excluding debuginfo, ppc arch,
repoview dirs, and even ISOs if need be.


Thanks,
Matt

-- 
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux

--