[Samba] stop winbind writes to disk

[Greg]

I'm trying to eliminate disk read/writes (as much as possible). Winbind is
one of the last problems for me. I was hoping that the -n switch would
disable caching and thus eliminate the writes to
/var/cache/samba/winbindd_cache.tdb. But I haven't had much luck.

To debug, I use the command string winbindd -i -d10 -n -s
/etc/samba/smb.conf and I get the following output:
[ 6796]: list trusted domains
secrets_get_trusted_domains: got 0 domains
Storing response for pid 6797, len 3240
fork_domain_child: domain PICTURE-FRAME no longer in 'startup' mode.
Destroying timed event 82e24d8 "async_request_timeout"
Retrieving response for pid 6797
Added timed event "async_request_timeout": 82e24d8
timed_events_timeout: 299/999938
child daemon request 19
process_request: request fn LIST_TRUSTDOM
[ 6796]: list trusted domains
secrets_get_trusted_domains: got 0 domains
Storing response for pid 6797, len 3240
Destroying timed event 82e24d8 "async_request_timeout"
Retrieving response for pid 6797
Added timed event "async_request_timeout": 82e24d8
timed_events_timeout: 299/999937
child daemon request 19
process_request: request fn LIST_TRUSTDOM

This repeats indefinitely as far as I can tell. Each of these sections
corresponds to a write action to the winbindd_cache.tdb file. Should I be
able to stop writes to winbindd_cache.tdb? Am I missing something?