[erlang-questions] simple virtual file system in Erlang?

Robert Raschke rtrlists@REDACTED
Wed Mar 29 13:53:51 CEST 2017


Two papers worth reading when thinking about storage and file systems:

Venti, a content addressable archival storage:
http://doc.cat-v.org/plan_9/4th_edition/papers/venti/
Fossil, a filesystem that can use venti for snapshot archives:
http://doc.cat-v.org/plan_9/4th_edition/papers/fossil/


On 28 March 2017 at 12:45, Joe Armstrong <erlang@REDACTED> wrote:

> You're quite right - you need to know in advance the checksum of the data.
>
> But obtaining the checksum from "somewhere" is orthogonal to the problem
> of storing or obtaining the data. Indexing etc. is completely different
> problem.
>
> /Joe
>
> On Mon, Mar 27, 2017 at 11:23 PM, Richard A. O'Keefe <ok@REDACTED>
> wrote:
> >
> >> On 27/03/2017, at 4:31 AM, Joe Armstrong <erlang@REDACTED> wrote:
> >> To store <blob>,  then later
> >>
> >>   GET /blob/sha256/<SHA>
> >>
> >> to recover the blob. <SHA> is the SHA256 checksum of the data (the
> >> path contains the
> >> type of the checksum - so you might say GETblob/md5/<MD5CHECKSUM>
> >
> > It seems to me that this amounts to using a checksum of the contents
> > of a file instead of an inode number.
> >
> > What I don't understand is how I would ever use this.
> > When I go looking for a file, I want its *contents*,
> > which I don't know, otherwise I wouldn't need it.
> > So I *can't* compute its checksum.  With things like
> > Spotlight, I can use a known *part* of the content to
> > look for the rest of the content, but again, if I
> > already knew enough of the content to compute the
> > checksum, I wouldn't bother looking at the file.
> >
> > The only way I can think of to use something like this
> > is to maintain some sort of name-based directory
> > structure on top, or some sort of IR-like inverted index
> > based on part of the content.
> >
> >
> _______________________________________________
> erlang-questions mailing list
> erlang-questions@REDACTED
> http://erlang.org/mailman/listinfo/erlang-questions
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20170329/885f4ff4/attachment.htm>


More information about the erlang-questions mailing list