[Samba] High CPU load with multiple SMB processes with Yosemite clients

[Luc Lalonde]

Hello Folks,

We just moved our Samba file server from version 3.6.3 to 4.2.10 (the 
lastest updates for CentOS 7.2).

Our Windows clients are working well, but we are unable to use it for 
our Mac clients (Yosemite).

The clients are configured to use their home directories from this file 
server.

Here's the config:

[global]
         workgroup = BLAH.COM
         netbios name = FILESERVER
         netbios aliases = FILESERVER
         server string = Serveur fichier INFO
         security = DOMAIN
         password server = LDAP.BLAH.COM
         encrypt passwords = Yes
         log file = /var/log/samba/%m.log
         max log size = 500
         load printers = No
         printing = cups
         cups server = cups.blah.com
         domain logons = No
         os level = 20
         local master = Yes
         preferred master = No
         domain master = No
         wins server = 132.207.180.14
         host msdfs = Yes
         socket options = TCP_NODELAY SO_KEEPALIVE IPTOS_LOWDELAY 
SO_SNDBUF=8192 SO_RCVBUF=8192
         kernel oplocks = yes
         strict locking = No
         oplocks = yes
         level2 oplocks = yes
         deadtime = 15
         unix extensions = yes
         wide links = yes
         allow insecure wide links = yes
         unix charset = UTF8
         unix password sync = No
         hide files = /Desktop.ini/RECYCLER/$RECYCLE.BIN/lost+found/
         smb ports = 445 139
         veto files = /Temporary Items/Network Trash 
Folder/.AppleDB/.AppleDouble/.AppleDesktop/.AppleDB/.DS_Store/
         delete veto files = Yes
         map untrusted to domain = Yes
         acl allow execute always = True

[homes]
         comment = homes
         read only = No
         directory mask = 0700
         force directory mode = 0700
         create mask = 0600
         force create mode = 0600
         browseable = No
         valid users = %S
         follow symlinks = yes

[profiles]
         comment = Users Profile Directories
         path = /store/profiles
         store dos attributes = Yes
         read only = no
         create mask = 0600
         directory mask = 0700
         profile acls = no
         csc policy = disable

I haven't tried recompiling the latest version (4.4.3) to see if I have 
the same behaviour...   I would like to keep the stock CentOS packages 
if I can.

Thank You!

-- 
Luc Lalonde, analyste
-----------------------------
Département de génie informatique:
École polytechnique de MTL
(514) 340-4711 x5049
Luc.Lalonde at polymtl.ca
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