[Samba] [CTDB] "use mmap = no" Causes wibind to fail

[Christian Kuntz]

Hello all,

I'm currently running samba on debian buster, version 2:4.9.5+dsfg-5 with
lustre 2.13.0.

The problem I'm experiencing is pretty straightforward, if I set "use mmap
= no" in my global config (as suggested by the wiki), winbind fails to
start and the cluster grinds to a halt. Here is the error messages from
systemd:

Sep 28 22:14:17 tenzin systemd[1]: Starting Samba Winbind Daemon...
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037190,  0]
../source3/lib/dbwrap/dbwrap_ctdb.c:1924(db_open_ctdb)
Sep 28 22:14:18 tenzin winbindd[21609]:   Could not open tdb
/var/lib/ctdb/volatile/g_lock.tdb.0: Invalid argument
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037574,  0]
../source3/lib/dbwrap/dbwrap_open.c:174(db_open)
Sep 28 22:14:18 tenzin winbindd[21609]:   failed to attach to ctdb
g_lock.tdb
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037626,  0]
../source3/lib/dbwrap/dbwrap_ctdb.c:1946(db_open_ctdb)
Sep 28 22:14:18 tenzin winbindd[21609]:   g_lock_ctx_init failed
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037677,  0]
../source3/lib/dbwrap/dbwrap_open.c:174(db_open)
Sep 28 22:14:18 tenzin winbindd[21609]:   failed to attach to ctdb
secrets.tdb
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037720,  0]
../source3/passdb/secrets.c:66(secrets_init_path)
Sep 28 22:14:18 tenzin winbindd[21609]:   Failed to open
/var/lib/samba/private/secrets.tdb
Sep 28 22:14:18 tenzin winbindd[21609]: [2020/09/28 22:14:18.037761,  0]
../source3/winbindd/winbindd.c:1800(main)
Sep 28 22:14:18 tenzin winbindd[21609]:   Could not initialize domain trust
account secrets. Giving up
Sep 28 22:14:18 tenzin systemd[1]: winbind.service: Failed with result
'protocol'.

And my testparm output:
[global]
clustering = Yes
disable spoolss = Yes
dns proxy = No
load printers = No
local master = No
log file = /var/log/samba/clients/%m.log
logging = syslog at 0 file
map to guest = Bad User
max log size = 100
max stat cache size = 65536
max xmit = 1048676
name resolve order = host wins bcast
ntlm auth = ntlmv1-permitted
printcap name = /dev/null
socket options = IPTOS_LOWDELAY SO_RCVBUF=131072 TCP_NODELAY
use mmap = No
username map cache time = 60
usershare path =
idmap config * : range = 1000000-1999999
idmap config * : backend = autorid
include = /etc/samba/smb-shares.conf
printing = bsd


[defaultsettings]
access based share enum = Yes
available = No
browseable = No
case sensitive = Yes
create mask = 0666
directory mask = 0777
include = /etc/samba/smb-shares.conf.local
read only = No
strict locking = No
use sendfile = Yes
vfs objects = catia fruit acl_xattr aio_pthread
readdir_attr:aapl_rsize = no
fruit:veto_appledouble = no
fruit:resource = file
fruit:metadata = stream
fruit:locking = none
fruit:encoding =


I've tested removing the "use mmap" line and the error disappears. The
documentation on the samba wiki (
https://wiki.samba.org/index.php/Configuring_clustered_Samba#Lustre_filesystem)
states that the setting is necessary to prevent possible corruption, but
states the last tested version was on the 1.4.x and 1.5.x versions of
lustre.

Is the wiki information still accurate? If so, what needs to change about
my configuration to fix this issue?
If the information is out of date and the modern utility of "use mmap = no"
is unknown, how can I test it?

As always, thank you for your time and attention,
Christian Kuntz

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