Switching backends

Switching backends

[Sebastian Tennant]

Belated happy International Worker's Day,

I'd like to switch backends and migrate all my old nnfolder mail to
nnml (for ease of indexing).

Switching backends isn't a problem, but how to perform the migration
of already 'processed' mail?

As nnfolder uses mbox format, I considered copying the nnfolder mbox
file back to the spool file (/var/mail/sebyte) to effectively respool
all my mail using the new nnml select method, but there's an issue
over nnfolder-added headers, and this being gnus I've no doubt there's
a much cleaner (and easier) way to go about this.

Any help much appreciated.

Sebastian

Re: Switching backends

[Kai Grossjohann]

Sebastian Tennant <sebyte@smolny.plus.com> writes:

> I'd like to switch backends and migrate all my old nnfolder mail to
> nnml (for ease of indexing).

First of all, you can keep your old nnfolder folders and migrate them
on a case-by-case basis, as needed.

Secondly, you can turn off topics mode in the group buffer, sort the
groups such that all nnfolder groups are together, then record a
keyboard macro that does the following:

- Extract the group name from the current line in the group buffer
  (sans nnfolder prefix).
- Create a new group with the same name in the nnml backend (with G m).
- Enter the nnfolder group, showing all articles, no threading.
- M P a to mark all articles.
- B m to move or B c to copy them into the nnml group.
- Exit the nnfolder group, returning to the group buffer.
- Advance to the next group in the group buffer.

Then execute that macro as often as needed.

This seems somewhat obvious, though, so I'm not sure if it really
helps.

Kai

Re: Switching backends

[Reiner Steib]

On Wed, May 02 2007, Kai Grossjohann wrote:

> Secondly, you can turn off topics mode in the group buffer, sort the
> groups such that all nnfolder groups are together, then record a
> keyboard macro that does the following: [...]

i guess that's more or less what the code I've posted in
<news:v9irs9u9hr.fsf@marauder.physik.uni-ulm.de> and
<http://thread.gmane.org/gmane.emacs.gnus.general/53276/focus=53300>
does.

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: Switching backends

[Sebastian Tennant]

Many thanks to all respondents.  I think I've got it, but until I try
I can't be sure :-/

Quoth Kai Grossjohann <kai@emptydomain.de>:
> This seems somewhat obvious, though, so I'm not sure if it really
> helps.

It certainly does help.  There's something about Gnus (probably the
fact that it is so infinitely configurable and possesses such a
dizzying array of variables) which has always made my head swim.

Sebastian

nnir bug?

[Sebastian Tennant]

In the thread 'Switching backends' quoth Kai Grossjohann <kai@emptydomain.de>:
> This seems somewhat obvious, though, so I'm not sure if it really
> helps.
>
> Kai

Hi Kai (et al),

Your advice was very helpful and I've switched gnus mail back ends.
(I always find doing something the first time a little bit hairy, but
now that I've done it, I can see why you thought it was 'somewhat
obvious').

Another issue has arisen, and being the author of nnir.el, there
couldn't be a better person to tell!

I've tried two different indexing back ends; swish-e, and most
recently, glimpse.  In the case of swish-e I added the following to my
~/.gnus:

 (require 'nnir)
 (setq nnir-search-engine      'swish-e
       nnir-swish-e-index-file "/home/sebyte/.gnus.d/nnml-index.swish-e")

Typing G-G in the group buffer, resulted in the message:

 gnus-group-read-ephemeral-group: Couldn't request group: Search produced empty results.

Even though swish-e searches worked fine on the command line (having
done the indexing, obviously) I decided to install and index my nnml
folder with glimpse instead, so I replaced the above lines in my
~/.gnus with the following:

 (require 'nnir)
 (setq nnir-search-engine                'glimpse
       nnir-glimpse-home                 "/home/sebyte/.gnus.d/glimpse"
       nnir-glimpse-remove-prefix        "/home/sebyte/.gnus.d/nnml/"
       nnir-glimpse-additional-switches  '("-i" "-w"))

Again, typing G-G in the Group buffer results in the same message,
despite the fact that glimpse searches work fine on the command line.

Am I simply missing something obvious? I hope not, because then I'm
going to feel very stupid indeed.  I fear that I am :-/

Sebastian

Re: Switching backends

[Karl Kleinpaste]

Sebastian Tennant <sebyte@smolny.plus.com> writes:
> Switching backends isn't a problem, but how to perform the migration
> of already 'processed' mail?

Create new nnml equivalents of old nnfolder groups.
Enter an nnfolder group.
If you care about the order in which the articles will be moved, then
re-sort it e.g. by date with `C-c C-s C-d'.
`M P a' to process-mark all articles.
`B m' to move the articles, selecting the equivalent nnml group.
Once you're sure that everything has moved as expected, arrange to
delete old nnfolder groups in *Group* with `G DEL'.