Mailing List Message #96236
From: <>
Subject: AW: Your experiences - MBOX vs MDIR
Date: Thu, 25 Sep 2008 07:23:26 -0700
To: <CGatePro>
X-Mailer: CommuniGate Pro MAPI Connector

Yes there is. I just had this problem few days ago.



Von: CommuniGate Pro Discussions [] Im Auftrag von Wayne Gamble
Gesendet: Dienstag, 23. September 2008 17:04
An: CommuniGate Pro Discussions
Betreff: Re: Your experiences - MBOX vs MDIR


"the only valid reason to use mdir is for easier differential backups.". 


Isn't there still a 2 GB/Folder limitation with mbox?


 - Wayne



On Sep 23, 2008, at 9:58 AM, Nicolas Hatier wrote:

In my opinion, since indexing have been implemented for the mbox format in CGP, the only valid reason to use mdir is for easier differential backups.

Mdir is slower for all read operations. mbox and mdir are approximately equivalent for append operations. mbox is probably slower for delete/purge operations, but compared to read and append, the delete operations happen a lot less often. This is for most filesystem, but I don't know all of them, ymmv.

In the past, when mbox was not indexed, opening a mailbox was a bit quicker using mdir, but this is not the case anymore, far from that. 

I'm still wondering why an mdir index can not be created, containing relevant header information for all message files.

Nicolas Hatier

Herbert Fischer wrote:



Despite all the facts and discussions we do about this two formats I would like to know more about your experiences on using both of this formats in CGP, including the file system used in any case. I know each one have advantages and disadvantages but most of the perceptions we only have in production environments.


I work in a ISP and host more than 1.5 million mailboxes and have all types of users using maildir format and some opensource adapted software.

We decided to go MBOX in CGP to reduce I/O on storages but we have raised some speculations on copy-on-write method used by ZFS, the choosen FS in this project.


Best regards,


Herbert G. Fischer

Subgerente de Arquitetura de E-mail


Locaweb – Keep IT Simple.
Eleita pela INFO Exame e pelo IDG Brasil
a melhor empresa em webhosting do país.


Geral: +55 11 3544-0444 R568




Nicolas Hatier
Niversoft idées logicielles




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