samba - Nov 2024 - tdb_expand overflow detected

On Wed, Nov 13, 2024, at 4:30 PM, Dan Langille via samba
wrote:
> Hello,
>
> I'm using samba416-4.16.11 on FreeBSD 14.1 (on ZFS, in a jail, with 
> quotas on those filesystems, etc)
>
> I'm seeing these entries in my logs. Is this something which needs 
> action?  If not, I'll start ignoring them.
>
> Nov 11 19:00:45 tm samba-dcerpcd[7373]: [2024/11/11 19:00:45.852391,  
> 0] ../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
> Nov 11 19:00:45 tm samba-dcerpcd[7373]:   
> tdb(/var/db/samba4/gencache.tdb): tdb_expand overflow detected current 
> map_size[4294967295] size[128]!
> Nov 11 19:00:45 tm samba-dcerpcd[7373]: [2024/11/11 19:00:45.853054,  
> 0] ../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
> Nov 11 19:00:45 tm samba-dcerpcd[7373]:   
> tdb(/var/db/samba4/gencache.tdb): tdb_expand overflow detected current 
> map_size[4294967295] size[128]!
> Nov 11 22:15:39 tm samba-dcerpcd[24174]: [2024/11/11 22:15:39.464471,  
> 0] ../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
> ...
The following is just one of the 343,930 log entries over a one hour period
(about 95 messages per second).

Nov 18 12:00:00 tm smbd[70983]: [2024/11/18 12:00:00.027823,  0]
../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
Nov 18 12:00:00 tm smbd[70983]:   tdb(/var/db/samba4/gencache.tdb): tdb_expand
overflow detected current map_size[4294967295] size[128]!

This appears to be a "Generic caching database for dead WINS servers and
trusted domain data." [1]. The same references says
"TDB_CLEAR_IF_FIRST means that Samba clears the TDB on each first open (for
example after a reboot). * will be only cleaned (truncated) if file is
corrupt"

I restarted samba. The file size did not change - conclusion: it is not corrupt.

My first guess to solve this issue:

* shutdown samba
* remove the file (/var/db/samba4/gencache.tdb)
* start samba

However, that doesn't seem to solve the problem. It's just making it go
away until it grows again.

Advice please?

1 - https://wiki.samba.org/index.php/TDB_Locations

-- 
  Dan Langille
  dan at langille.org

On 19/11/24 02:27, Dan Langille via samba wrote:
> On Wed, Nov 13, 2024, at 4:30 PM, Dan Langille via samba wrote:
>> Hello,
>>
>> I'm using samba416-4.16.11 on FreeBSD 14.1 (on ZFS, in a jail, with
>> quotas on those filesystems, etc)
>>
>> I'm seeing these entries in my logs. Is this something which needs
>> action?  If not, I'll start ignoring them.
>>
>> Nov 11 19:00:45 tm samba-dcerpcd[7373]: [2024/11/11 19:00:45.852391,
>> 0] ../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
>> Nov 11 19:00:45 tm samba-dcerpcd[7373]:
>> [...]
> 
> The following is just one of the 343,930 log entries over a one hour period
(about 95 messages per second).
> 
> Nov 18 12:00:00 tm smbd[70983]: [2024/11/18 12:00:00.027823,  0]
../../lib/tdb_wrap/tdb_wrap.c:65(tdb_wrap_log)
> Nov 18 12:00:00 tm smbd[70983]:   tdb(/var/db/samba4/gencache.tdb):
tdb_expand overflow detected current map_size[4294967295] size[128]!
Is the file system size of /var/db/samba4/gencache.tdb also 4294967295?

I think something outside of tdb must be causing this to go haywire.

What are the last messages before this starts happening?

Douglas