[Samba] Inconsistent performance (4.1.6)

[gabe mart]

All,

I have a Solaris 11.1 (x86_64) server using ZFS as the storage facility
running samba version 4.1.6. I have several clients that seem to transfer
files to and from the server at acceptable rates (~80 MB/s) read and write.
 The problem is that I also have several clients that transfer at a very
inhibited rate (~1 MB/s).  These clients are W7 (x64) both physical
machines and virtual.  I also have mac clients that exhibit the same slow
transfer rate connecting with smb://retina/share and even slower rates when
connecting it NT1 protocol (cifs://retina/share).  The mac clients are
strange in that the performance seems to be asymmetric; transfers from the
server are much slower than to the server.

I've done testing on a few of these machines to see if the performance was
affected by subnet or switch configuration.  It does not seem to be related
to that as the performance was consistently bad for those machines
everywhere.

This server is configured as an LDAP client with kerberos authentication
and the samba server is bound to AD as a member server.  All log files are
quiet at current log level.

Below is the config file from the server.

[global]

   interfaces = net4


   workgroup = DOM

   netbios name = retina

   security = ADS

   realm = LOCAL.DOM


   socket options = IPTOS_LOWDELAY TCP_NODELAY SO_RCVBUF=131072
SO_SNDBUF=131072

   aio read size = 16384

   aio write size = 16384

   write cache size = 268435456

   min receivefile size = 16384

   read raw = no

   write raw = no
   vfs objects = streams_xattr


   client use spnego = yes

   encrypt passwords = yes

   local master = no

   os level = 33

   domain master = no

   preferred master = no

   wins support = no

   wins server = 192.168.16.5 192.168.164.42 192.168.181.100

   ntlm auth = no

   lanman auth = no

   client lanman auth = no

   client ntlmv2 auth = yes

   client min protocol = nt1

   server min protocol = nt1

   server role = member server


   server signing = auto

   client signing = auto


   username map = /usr/local/bin/AD_to_localname.sh


   name resolve order = wins host lmhosts bcast


   log file = /var/samba/log/log.%m


   max open files = 32768


   # fix mac client issues.  hanging mounts

   veto files = /._*/.DS_Store/

   delete veto files = yes


   log level = 0

   syslog = 0

   load printers = no

   printcap name = /dev/null

   [shares below here]


Your insight is welcome.

----gabe