From: pukkamustard <pukkamustard@posteo.net>
To: "Ludovic Courtès" <ludo@gnu.org>
Cc: guix-devel@gnu.org
Subject: Re: Identical files across subsequent package revisions
Date: Tue, 29 Dec 2020 21:01:33 +0100 [thread overview]
Message-ID: <86v9ckmleq.fsf@posteo.net> (raw)
In-Reply-To: <87wnx9wlea.fsf@gnu.org>
Hi Ludo,
>
> Thoughts? :-)
>
Super cool! :)
Your research inspired me to do conduct some experiments towards
de-duplication.
For two similar packages (emacs-27.1 and emacs-26.3) I was able to
de-duplicate ~12% using EROFS and ERIS. Still far from the ~85%
similarity, but an attempt I'd like to share.
The two main ingredients:
- EROFS (Enhanced Read-Only File-System) is a read-only,
compressed
file-system comparable to SquashFS. It has some properties that
make
it more suitable than SquashFS (it aligns content to fixed block
size). EROFS is in mainline Linux Kernel since v5.4.
- ERIS (Encoding for Robust Immutable Storage) is an encoding of
content
into uniformly sized blocks that I've been working on. It
de-couples
encoding of content from storage and transport layer. Transport
layers
can be things like IPFS, GNUNet, Named Data Network or just a
plain
old HTTP service.
I make EROFS images of the packages and encode them with ERIS,
which
de-duplicates blocks as part of the encoding process.
With this I manage to de-duplicate between 12-17% (depending on
some
parameters).
This could allow:
- Directly mounting packages instead of unarchiving (a la distri)
- Peer-to-peer distribution of packages (that's what ERIS is for)
- De-duplicating common content in packages to a certain extent
(topic
of this thread)
A more in-depth write-up:
https://gitlab.com/openengiadina/eris/-/tree/main/examples/dedup-fs
Happy Hacking!
-pukkamustard
next prev parent reply other threads:[~2020-12-30 14:13 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 22:01 Identical files across subsequent package revisions Ludovic Courtès
2020-12-23 9:08 ` Taylan Kammer
2020-12-23 10:50 ` Pierre Neidhardt
2020-12-23 22:06 ` Mark H Weaver
2020-12-23 22:47 ` Jonathan Brielmaier
2020-12-23 23:42 ` Mark H Weaver
2020-12-23 10:19 ` zimoun
2020-12-23 10:41 ` zimoun
2020-12-27 22:22 ` Ludovic Courtès
2020-12-23 11:48 ` Christopher Baines
2020-12-23 13:10 ` Miguel Ángel Arruga Vivas
2020-12-23 14:07 ` zimoun
2020-12-23 15:40 ` Julien Lepiller
2020-12-23 19:07 ` Miguel Ángel Arruga Vivas
2020-12-27 22:29 ` Ludovic Courtès
2021-01-06 9:39 ` Ludovic Courtès
2020-12-29 20:01 ` pukkamustard [this message]
2021-01-06 9:27 ` Ludovic Courtès
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