Re: Future of Qmail-LDAP

On 02/03/2010 10:58 AM, Scott Ryan wrote:
> No capability to store message blobs compressed.
> No ability to strip the meta data from the message thus being able to
> provide this info to pop3 / IMAP without using disk I/O.
> No ability to be able to link 1 attachment to multiple messages.
> No ability to move old/read messages to slower/cheaper storage
>
> All this adds up to requiring colossal amounts of high speed,
> expensive storage if you want to offer large mailboxes for millions of
> users.
>
>    


I can see your point.

I was just wondering if when you say "mailboxes" you do really mean 
mailboxes, or maildirs?

Also, i should note that IMHO Qmail-LDAP should focus on the MTA part. 
There are way better POP and IMAP solutions out there, like Dovecot for 
instance. If someone asked me about it, i would vote for dropping the 
POP and IMAP server stuff and concentrate on message acceptance and 
delivery.

Now about what you think should be supported:

- Compressed message blobs. That's for reading only, right? I'm not 
aware of compressed files being opened for writting on-the-fly, 
anywhere. If that's the case, i state my opinion on the above paragraph.

- Where should that metadata be available? Is reading messages stored in 
single files (maildir), to extract metadata, that much I/O expensive 
than to keep that data in a database?

- Message/File deduplication. That i would also love to see. 
Theoretically it's actually rather simple to do. I just need to strip 
the attachments from the messages and store them somewhere with unique 
names, like using the md5sum of the file, for instance. Then your 
message will no longer keep the attachment inside, but a reference to 
the detached attachment. You would also need to maintain a reference on 
that attachment so you could know what messages currently depend on it. 
The other part, of removing orphaned attachments, would be done by the 
POP/IMAP server.

- Ability to move old/read messages to slower/cheaper storage. That's 
not the job of an MTA. That would be the job for an IMAP server/system. 
I believe Dovecot already allows something like that.


Anyone got more ideas/solutions?

Regards,

Hugo Monteiro.

-- 
fct.unl.pt:~# cat .signature

Hugo Monteiro
Email	 : [email protected]
Telefone : +351 212948300 Ext.15307
Web      : http://hmonteiro.net

Divisão de Informática
Faculdade de Ciências e Tecnologia da
		   Universidade Nova de Lisboa
Quinta da Torre   2829-516 Caparica   Portugal
Telefone: +351 212948596   Fax: +351 212948548
www.ci.fct.unl.pt	      [email protected]

fct.unl.pt:~# _