Dovecot does not start on MacOS Monterey

[Shawn Heisey]

On 10/26/22 04:27, Doro Rose wrote:
> Thanks for the quick response!
> No. If I set default_vsz_limit to 0 it works. My understanding was 
> that this shouldn't be necessary in the first place, shouldn't it?

Most systems and software do not limit the virtual memory size. This is 
because virtual memory is just address space until something actually 
uses it, and the OS can ensure that an application that is working 
correctly with regard to virtual memory will NOT allocate too much real 
memory because of virtual memory.

Dovecot is actually the only software I have seen that has a native 
config for limiting the virtual memory size.  I know why it's done ... 
there are certain classes of bug that can result in virtual memory 
leakage.  Because virtual memory is NOT real memory, this class of bug 
might go unnoticed if there is no limit.  Putting a limit on the size 
makes sure that bugs of that nature ARE caught.

My dovecot install is not huge ... only 200K total email messages 
stored.  But I had to increase the default_vsz_limit to get dovecot 
working.  I think it defaults to 256M, I increased it to 1024M.  
Dovecot's log should tell you how much virtual memory Dovecot is 
requesting, if the request fails.

Thanks,
Shawn