Re: message_size_limit documentation

2021-12-23 Thread Wietse Venema
Scott Kitterman:
> Thanks.  I don't think it's worth a lot of effort.  I'd imagine it's a pretty 
> niche use case to send multi-gigabyte files via SMTP.  People do do it though 
> (clearly or there wouldn't be a bug).
> 
> I wrestled with a few options for a simple explanation, but didn't come up 
> with anything I particularly liked.  I think it's correct that there's a hole 
> in the documentation, but I don't have a good recommendation on how to fill 
> it.

In Postfix 3.7 I have updated the text for message_size_limit.

message_size_limit (default: 1024)
   The maximal size in bytes of a message, including envelope information.
   The  value cannot exceed LONG_MAX (typically, a 32-bit or 64-bit signed
   integer).

Ditto for mailbox_size_limit.

Wietse


Re: message_size_limit documentation

2021-12-23 Thread Scott Kitterman
On Thursday, December 23, 2021 3:51:57 PM EST Wietse Venema wrote:
> Scott Kitterman:
> > Currently, postconf.5 has this to say about message_size_limit:
> > 
> > message_size_limit (default: 1024)
> > 
> > The maximal size in bytes of a message, including envelope
> > information.
> > 
> > Note: be careful when making changes. Excessively small values will
> > result
> > 
> > in the loss of non-delivery notifications, when a bounce message size
> > exceeds the local or remote MTA's message size limit.
> > 
> > 
> > It documents the default, but not the maximum.
> 
> The maximum is determined by (kernel) resource limits, file system sizes,
> and...
> 
> >  Apparently there is one (and
> > 
> > who would care, one of Debian's users, apparently [1]).  I'm not
> > particularly confused about why there would be a maximum, but it might be
> > reasonable to document what it is.  Perhaps add something like "Maximum
> > value is 2147483647." at the end of the note so that users don't have to
> > find out the hard way:
> > 
> > fatal: bad numerical configuration: message_size_limit = 2147483648
> 
> That is the LONG_MAX value for 32-bit machines. It's much bifgger
> for 64-bit systems.
> 
> I guess we could put that in the manpage. I have ab old wishlist
> item to migrate file sizes from to off_t (which is 64 bits on
> most systems).
> 
> But that is a lot of effort, and I was kind-of hoping that 32-bit
> systems will go away.

Thanks.  I don't think it's worth a lot of effort.  I'd imagine it's a pretty 
niche use case to send multi-gigabyte files via SMTP.  People do do it though 
(clearly or there wouldn't be a bug).

I wrestled with a few options for a simple explanation, but didn't come up 
with anything I particularly liked.  I think it's correct that there's a hole 
in the documentation, but I don't have a good recommendation on how to fill it.

Scott K




Re: message_size_limit documentation

2021-12-23 Thread Wietse Venema
Scott Kitterman:
> Currently, postconf.5 has this to say about message_size_limit:
>
> message_size_limit (default: 1024)
>
> The maximal size in bytes of a message, including envelope information.
>
> Note: be careful when making changes. Excessively small values will result
> in the loss of non-delivery notifications, when a bounce message size exceeds
> the local or remote MTA's message size limit.
>
>
> It documents the default, but not the maximum.

The maximum is determined by (kernel) resource limits, file system sizes, 
and...

>  Apparently there is one (and
> who would care, one of Debian's users, apparently [1]).  I'm not particularly
> confused about why there would be a maximum, but it might be reasonable to
> document what it is.  Perhaps add something like "Maximum value is
> 2147483647." at the end of the note so that users don't have to find out the
> hard way:
>
> fatal: bad numerical configuration: message_size_limit = 2147483648

That is the LONG_MAX value for 32-bit machines. It's much bifgger
for 64-bit systems.

I guess we could put that in the manpage. I have ab old wishlist
item to migrate file sizes from to off_t (which is 64 bits on
most systems).

But that is a lot of effort, and I was kind-of hoping that 32-bit
systems will go away.

Wietse

> Scott K
>
> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960272
>
>
>