Re: [Evolution] Expunging

[Patrick O'Callaghan <poc usb ve>]

On Fri, 2008-06-27 at 09:46 +0200, Svante Signell wrote:
> On Thu, 2008-06-26 at 15:19 -0430, Patrick O'Callaghan wrote:
> > On Thu, 2008-06-26 at 20:58 +0200, Svante Signell wrote:
> > > I assume this question has been asked before, maybe it is even in some
> > > FAQ. I am short of disk space and ~/.evolution is the main cause of
> > > this. Trying to reduce the size of folders I delete a lot of mails, but
> > > the largest folders cannot be expunged due to the lack of disk space. Is
> > > there an option where I can expunge mail folders without a backup copy
> > > is created (or similar happening, remaining disk is reduced before being
> > > increased)?
> >
> > If you're talking about mbox-style folders (you don't say) then
> > expunging necessarily requires making a copy, though the size of the
> > copy depends on the space occupied by the remaining emails. This is
> > because an mbox folder is a single large file and Linux doesn't support
> > taking space away from the middle of a file. Although copying in-place
> > would theoretically work, that would be dangerous if interrupted and Evo
> > doesn't do it.
>
> Yes, the mail is stored in mbox format. I have some follow-up questions:
>
> 1) Is it possible to just move one large file to somewhere else,
> expunging other folders and move it back? 

I've never done this, but as long as you don't touch the file from Evo
(i.e. visit the folder) and of course assuming it's not your Inbox, then
I don't see why not.

> 2) In .evolution/cache/ I currently have 100MB, mainly contained in the
> html subdirectory. Is there a way to clear this cache from evolution.
> Have not found such option yet. What about just removing the files
> under .../cache/html/??/ and .../cache/tmp?

Just remove them. Evo will recreate anything it needs.

> 3) Is it possible to specify another tmp directory than
> under .evolution?

AFAIK not directly (though gconf-editor might be a way). However you can
create a temp directory somewhere else and place a symbolic link to it
where Evo expects to find it. Be sure to stop Evo completely (evolution
--force-shutdown) before doing this.

> 4) Can I edit the mbox folders manually, e.g. in emacs. I've done so
> successfully before but it seems to be somewhat risky.

Yes, although it will mess up the index files, but you can remove these
and Evo will recreate them. Again, use --force-shutdown to stop Evo
before doing this. However if you don't have enough space for an
expunge, I don't see how you're going to be able to edit large mbox
files, since an expunge is essentially just that.

> 5) Where can I find a description of the set of files for each folder,
> e.g. Inbox, Inbox.cmeta, Inbox.ev-summary, Inbox.ev-summary-meta,
> Inbox.ibex.index, Inbox.ibex.index.data
> Why so many sub-files in addition to the main one Inbox?

Several reasons. Some are indices into the mbox file (which is a
potentially very large linear file with messages separated by an inline
syntactic convention, making it inefficient to jump randomly between
messages). Some are caches of message state, which eventually has to be
pushed to a mail server (e.g. for IMAP). Others are there because Evo
supports folder nesting and the mbox format doesn't, so it needs extra
information. Offhand I can't point you to a unified description of all
this, but http://www.go-evolution.org/Main_Page might be a place to
start.

poc