[Samba] Samba 4 + Zimbra 8

[Mārtiņš Gailītis]

Hello!

I have a setup - Samba 4 for AD functionality and Zimbra 8 for e-mail and collaboration.
Configured in Zimbra that for authentication Samba 4 has to be used. Basically it works, but now randomly one time in two or three days authentication just stops working. Nobody is able to log in to Zimbra e-mail.
Had to restart samba and everything goes as nothing ever happened! :(
Last entry in log.samba is:
[2013/05/14 11:11:06,  0] ../auth/ntlmssp/ntlmssp_sign.c:236(ntlmssp_check_packet)
  NTLMSSP NTLM2 packet check failed due to invalid signature!
But it was written in log ~1,5 hours before it happened!
Before service restart 'ps -ef | grep samba' showed:
root      4486     1  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4487  4486  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4488  4486  0 08:27 ?        00:00:09 /usr/local/samba/sbin/samba -D
root      4489  4486  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4490  4486  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4491  4487  0 08:27 ?        00:00:01 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
root      4492  4486  0 08:27 ?        00:00:38 /usr/local/samba/sbin/samba -D
root      4493  4486  0 08:27 ?        00:00:02 /usr/local/samba/sbin/samba -D
root      4494  4486  0 08:27 ?        00:00:03 /usr/local/samba/sbin/samba -D
root      4495  4486  0 08:27 ?        00:00:05 /usr/local/samba/sbin/samba -D
root      4496  4486  0 08:27 ?        00:00:01 /usr/local/samba/sbin/samba -D
root      4497  4486  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4498  4486  0 08:27 ?        00:00:02 /usr/local/samba/sbin/samba -D
root      4499  4486  0 08:27 ?        00:00:00 /usr/local/samba/sbin/samba -D
root      4502  4491  0 08:27 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
root      4516  4491  0 08:29 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
root      5004  4491  0 10:08 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
root      5438  4491  0 11:36 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
root      5746  4491  0 12:38 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
3000071   6291  4491  0 13:32 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground
3000067   6297  4491  0 13:32 ?        00:00:00 /usr/local/samba/sbin/smbd -D --option=server role check:inhibit=yes --foreground


Does anybody have idea where to dig?! Is there any other logs or verbose/debug mode how to find out what causes this unexpected stop?!

regards,
Martins