Thanks Aki, this points me in the right direction.

To clarify (and for other novices like me that have a similar issue), I'm running the mail server on a QEMU VM and using 9p passthru to access a host folder where all mail is stored. According to the 9p docs, by default no caching is used. There is a mount option "cache=mmap".

The current fstab entry is simply:

shares   /shares    9p  trans=virtio,version=9p2000.L,rw,user 0   0

I added the option:

shares   /shares    9p trans=virtio,version=9p2000.L,cache=mmap,rw,user    0   0

And so far the log looks very clean! I suspect this could be the source of my index.cache issues that were constantly occurring also.

If you spot or know of any traps in this reasoning let me know.

Thanks for the help!

Eric

On 12/02/2017 08:51 AM, Aki Tuomi wrote:

...

On December 2, 2017 at 5:36 PM GE Junkjunk.ge@planetmorgan.net wrote:

I get a ton of these mmap() errors in the log. I noticed there's a double slash before Maildir. Is this normal? Config error? Dovecot bug?

dovecot: imap(email@email.net): Error: mmap() failed with file /shares/email/vmail/vmail1/email.net/e/m/a/email-2017.02.25.08.09.39//Maildir/dovecot.index.cache: Invalid argument

I'm running dovecot version 2.2.22

Thanks Eric Most likely the file system does not support mmap. Is it some remote filesystem, such as NFS? You probably can get better results by disabling mmap from dovecot.

Aki