[tahoe-dev] backup, revision control (was: using Tahoe-LAFS when you only have one server)

[Zooko O'Whielacronx]

On Sat, Jan 15, 2011 at 6:26 AM, Greg Troxel <gdt at ir.bbn.com> wrote:
>
> git lets you keep history against accidental deletion, and I don't see
> tahoe doing that.

Have you tried "tahoe backup"?

It stores an immutable snapshot of your filesystem every time you run
it. Here's an example:

http://alpha.zooko.com:3458/uri/URI%3ADIR2-RO%3Ao7mbbpxsznwfwiih5yzxmuqopq%3Acl72f3dnb6q7z4ajfjw24me5qwk7q7hfqrp5ho3dntuvoovspska/

This isn't nearly as fine-grained and efficient as git, of course. I
wouldn't want to use "tahoe backup" for revision control! But it is
pretty good for getting access to your older backup snapshots. It is
also cool that you can share specific subsets of your backups with
others. For example, instead of giving you that link above (which
gives you read-only access to my entire history of backups of my PDF
collection, including future backups), I could have given you this
link:

http://alpha.zooko.com:3458/uri/URI%3ADIR2-CHK%3Asgqpnw5rsie5rf7fjrcdh3reje%3Ay35trl3py7c5ocf4eugnlxzehjadl3tfpcytrggekvytmjhin7vq%3A7%3A8%3A19776

That one gives you read access to the immutable version of just the
"diet_research" subdirectory as it existed on 2011-01-13_16:06:50Z.

>  So for lots of little files, using git and then
> putting the .git into tahoe makes sense to me.

That's an interesting option, too. When Brian and I presented
Tahoe-LAFS at the RSA Conference 2010, I met a guy in the hallway
afterward who whispered (literally!) that he worked for NSA and that
he was interested in combining Tahoe-LAFS and git so that he could
share revision control with people of different secrecy-privilege
levels without exposing all of the source code to all of the
programmers.

Nils Durner also made sure that you could point bzr at your Tahoe-LAFS
SFTP server [1], Marc Tooley made a script to point Perforce at a
Tahoe-LAFS backend [2], Nathan Wilcox wrote a thing to explode your hg
history into a Tahoe-LAFS filesystem tree of some sort [3], and I for
my part just run "tahoe cp -r" to copy one of my darcs repositories
into a grid, so you should be able to run the following command to
fetch that repository from Tahoe-LAFS:

darcs get --lazy
http://alpha.zooko.com:3458/uri/URI%3ADIR2-RO%3A5nucyvgod2b5gstupfc4rgdcxy%3Ab6exmhsqxyi4mvehwrpwczmcbtqlnw6mh7vmny4xop3ltblgaeqq/

:-)

> What I've done so is take a directory, tar it up, gpg encrypt it, and
> then drop it in a grid.   Overly paranoid maybe, but cap handling isn't
> as careful as key handling.

Why not? I'd like to know more about this! Do tell. :-)

Regards,

Zooko

[1] https://bugs.launchpad.net/tahoe-lafs/+bug/294709
[2] http://tahoe-lafs.org/pipermail/tahoe-dev/2009-June/002105.html
[3] http://tahoe-lafs.org/pipermail/tahoe-dev/2010-June/004559.html