Dovecot v2.3.13 reporting (very) incorrect vsize for some maildir folders

[Eirik Rye]

> On 20 May 2021, at 13:44, Timo Sirainen <timo at sirainen.com> wrote:
> 
> You can also look at the folder-level vsizes to see which one is causing the differences (or are they all doubled?)

In this user's case, it is only the Trash-folder that has the wrong vsize calculation:

# doveadm mailbox status -u <username> 'messages vsize' '*'
Drafts messages=0 vsize=0
Sent messages=0 vsize=0
Trash messages=14870 vsize=14584428026
Spam messages=3 vsize=227701
INBOX messages=1866 vsize=1640766021

The other mailboxes (INBOX and Spam) are both within what I consider reasonable in terms of differences in virtual/physical sizes:

# du -bs /mail/<username>/Maildir/cur
1603071610      /mail/<username>/Maildir/cur
# du -bs /mail/<username>/Maildir/.Spam
241489  /mail/<username>/Maildir/.Spam

But the Trash mailbox is physically HALF the size of what Dovecot reports:

# du -bs /mail/<username>/Maildir/.Trash
7200481589      /mail/<username>/Maildir/.Trash

The message count reported by dovecot (14870) is correct, however:

# ls /mail/<username>/Maildir/.Trash/cur | wc -l
14870

With the other users I have noticed the same issue, it's a different mailbox and not Trash.

One user has a mailbox reported by Dovecot as being ~13.7GB while it is actually physically only around 0.3GB. For this user I haven't tried stripping W= sizes or deleting dovecot control files, though.

- Eirik