MBOX-Line: From eluis.linux at gmail.com  Wed May  5 13:00:34 2010
To: imap-protocol@u.washington.edu
From: =?ISO-8859-1?Q?Eduardo_Lu=EDs?= <eluis.linux@gmail.com>
Date: Fri Jun  8 12:34:43 2018
Subject: [Imap-protocol] 2Gb size limit
In-Reply-To: <alpine.OSX.2.00.1005051145060.709@hsinghsing.panda.com>
References: <j2z2548ae4f1005050127j2ebd4af5w95af8888b9e0a185@mail.gmail.com> 
	<h2l39e9aab51005050242xc44fa182ge03c6ba8f70ca6e4@mail.gmail.com> 
	<z2p2548ae4f1005050300wb1b0abdew4ba33f8a9d74f0ab@mail.gmail.com> 
	<alpine.OSX.2.00.1005051145060.709@hsinghsing.panda.com>
Message-ID: <q2x2548ae4f1005051300u4ca18e39pf5433bae636d98d7@mail.gmail.com>

Ok Mark, thanks a lot for your explanation...
I have to switch to a mixed format....

Thank you,

Eduardo Lu?s



2010/5/5 Mark Crispin <mrc+uw@panda.com>:
> On Wed, 5 May 2010, Eduardo Lu?s wrote:
>>
>> No, it's not a 32bit OS feature.
>
> Actually, it is your OS.
>
> UW IMAP uses unsigned longs (it was largely written before off_t was
> universally defined) which would support at least 4GB.
>
> The problem is that off_t is defined on many systems as an int32, and the
> lseek() call takes an off_t. ?This is the cause of the 2GB limit.
>
> On other systems, off_t is defined as an int64. ?The limit should be 4GB,
> not 2GB, on those system.
>
> If you have a int32 off_t, then you need to do one of the following:
>
> On some systems, you must change everything to use lseek64() call and
> off64_t.
>
> On other systems, it is possible to fix lseek() and off_t by defining
> _FILE_OFFSET_BITS to 64. ?That will make off_t be an int64. ?If ulong on
> your system is a uint32, that should give you up to a 4GB limit; if ulong
> on your system is a uint64 then you win big.
>
>
> Personally, I think that it is completely, utterly, insane to have a flat
> mailbox file greater than 2GB; or for that matter much greater than 100MB.
> Flat file formats were never intended to scale to such sizes.
>
> You should use the mix format instead, which breaks the mailbox into
> multiple files that are either 1MB or the size of a single message,
> whichever is larger.
>
> Now, if you have a single message which is greater than 2GB (or 4GB), then
> you have other problems.
>
> -- Mark --
>
> http://panda.com/mrc
> Democracy is two wolves and a sheep deciding what to eat for lunch.
> Liberty is a well-armed sheep contesting the vote.

