Coda File System

Re: Migration procedure

From: Jerry Amundson <jerry_at_pbs.com>
Date: Wed, 17 Nov 2004 17:11:55 -0600
On Wednesday 17 November 2004 03:24 pm, Jan Harkes wrote:
> So many questions,

But one answer that matters most, when it comes right down to it...

> On Tue, Nov 16, 2004 at 11:52:04PM -0600, Jerry Amundson wrote:
> > On Tue November 16 2004 8:57 pm, Stephen J. Turnbull wrote:
> > > this limit is given in bytes (256K, IIRC), not dentries, I
> > > suppose that a somewhat imprecise "file too large" error might be
> > > issued when you run out of space for more entries in a directory.
> >
> > Could be, I didn't think that would rear it's ugly head so soon,
> > though.
> >
> > [root_at_uhura vicepa]# find 0 | wc -l
> > 2717
>
> If the filenames are shorter than about 32 characters I would expect
> the limit to hit around 4000 entries in a single directory
> (approximately 32 for the name + probably another 32 for other data
> per entry ). My maildir filenames are already 25 characters long but
> only seem to use only the hostname and not the fully qualified domain
> name. If it were to use the fqdn most files exceed 32 bytes and end
> up getting padded to the next multiple of 32, limiting the total size
> to 256K/96 = 2730.
>
> All of these numbers are approximate, there is some additional
> padding going on and I think there is some reserved space for an
> allocation bitmap and such. The 'rvmsizer' tool contains the full
> formula and will display a warning whenever it encounters a directory
> that won't fit in the existing Coda directory structure.
>
> Considering how close your measured 2717 and my estimated 2730
> entries are I guess that your filenames contain the fully qualified
> domain name and are typically longer than 32 bytes.

That was one of my worries when I first started this six weeks ago. 
http://www.coda.cs.cmu.edu/maillists/codalist/codalist-2004/6922.html

We use Courier, from http://www.courier-mta.org - great software, but it 
has maildirs implemented with everything but the kitchen sink:
1100718424.M676970P29704V0000000000000807I00784E58_354.uhura,S=1866:2,

So, with several users having 5000, 6000, 8000 messages in an Inbox, use 
of Coda is all but impossible. :-(

Unfortunately, I don't have time right now to code anything, either to 
Courier or Coda, to facilitate this.

jerry
Received on 2004-11-17 18:13:27