При запуске команды тестирования конфигурации Samba, я обратил внимание на ошибку.

rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)

Это количество одновременно открытых файлов у нас это 1024, а для Windows это 16384.

# /usr/local/samba/bin/testparm 
Load smb config files from /usr/local/samba/etc/smb.conf
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
Processing section "[netlogon]"
Processing section "[sysvol]"
Processing section "[test]"
Loaded services file OK.
Server role: ROLE_ACTIVE_DIRECTORY_DC
Press enter to see a dump of your service definitions

Гугление привело к решению. Нужно добавить строку 

*		-	nofile		16384

в файл

/etc/security/limits.conf

Должно получиться нечто такое:

# cat /etc/security/limits.conf
# /etc/security/limits.conf
#
#Each line describes a limit for a user in the form:
#
#            
#
#Where:
# can be:
#        - an user name
#        - a group name, with @group syntax
#        - the wildcard *, for default entry
#        - the wildcard %, can be also used with %group syntax,
#                 for maxlogin limit
#        - NOTE: group and wildcard limits are not applied to root.
#          To apply a limit to the root user,  must be
#          the literal username root.
#
# can have the two values:
#        - "soft" for enforcing the soft limits
#        - "hard" for enforcing hard limits
#
# can be one of the following:
#        - core - limits the core file size (KB)
#        - data - max data size (KB)
#        - fsize - maximum filesize (KB)
#        - memlock - max locked-in-memory address space (KB)
#        - nofile - max number of open files
#        - rss - max resident set size (KB)
#        - stack - max stack size (KB)
#        - cpu - max CPU time (MIN)
#        - nproc - max number of processes
#        - as - address space limit (KB)
#        - maxlogins - max number of logins for this user
#        - maxsyslogins - max number of logins on the system
#        - priority - the priority to run user process with
#        - locks - max number of file locks the user can hold
#        - sigpending - max number of pending signals
#        - msgqueue - max memory used by POSIX message queues (bytes)
#        - nice - max nice priority allowed to raise to values: [-20, 19]
#        - rtprio - max realtime priority
#        - chroot - change root to directory (Debian-specific)
#
#                 
#

#*               soft    core            0
#root            hard    core            100000
#*               hard    rss             10000
#@student        hard    nproc           20
#@faculty        soft    nproc           20
#@faculty        hard    nproc           50
#ftp             hard    nproc           0
#ftp             -       chroot          /ftp
#@student        -       maxlogins       4

# End of file

*		-	nofile		16384

После обязательна перезагрузка.