[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Jigdo - A Professional Letter to Mike McGrath



Jonathan Steffan wrote:
The amount of storage and bandwidth able to be saved can be illustrated
by a simple comparison between the efficiency of chopping up a 3.4GB
iso9660 file system arbitrarily (by a static chunk size) and the same
file system based on contents (file by file.) For a BitTorrent,
Fedora's current choice for sharing Spins, the hosted data is only
valid for a given chunk on a single ISO. This data's footprint (equal
to the combined chunk sizes of the entire torrent) can be used for
nothing but this Spin. To be able to host 5 Spins composed from similar
trees via BitTorrent, we now have a footprint of 17GB, not to mention
"seeders" have to run BitTorrent software to be able to contribute to
the swarm. Alternatively, Jigdo can be used to reduce the footprint of
these 5 Spins to about 4GB. The amount of additional data needing to be
hosted for each Spin, in addition to what data is already pushed to the
mirrors, is about 150MB per ISO with anaconda and about 200KB for ISOs
without the installer bits. To help illustrate the efficiency of using
Jigdo vs BitTorrent, the footprint for 250 Spins is 850GB for
BitTorrent and about 40GB for Jigdo. Additionally, a reduction in
overhead can be achieved by removing the need for the BitTorrent
tracker and all related network traffic without requiring any
additional work on the part of mirror administrators.

This paragraph shows the savings we would make on the jigdo server. How much would our storage needs increase by needing to keep all RPM's around on the mirrors?

   -Mike


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]