maildir very dirty sync option

[Hendrik Boom]

On Tue, Aug 20, 2019 at 10:05:59AM +0300, Yousif Alkhateeb via dovecot wrote:
> Hello ,
> 
> I have an active passive dovecot setup with glusterfs as a mail storage and
> using maildirs, we used to have a problem when users with large mailboxes
> sync their folders. This caused the load average to increase in the server
> , after a while we have enabled the very_dirty_sync option in dovecot ,
> things got better and the problem disappeared but we need to know if there
> is any thing else that we need to do or know about the very_dirty_sync
> option that may cause future problems .

What's the scale of this problem?  I.e., how large are the troublesome 
"large mailboxes"?  A gigabyte?  A terabyte?  a few megabytes?

-- hendrik