samba - Feb 2017 - Need help troubleshooting TCP thrashing, possible kernel bug?

I think it should be neither. Ugh... FreeNAS UI doesn't let me disable the
Domain Logons setting for some reason, so I'll have to talk to them on that
one and it seems they have no option for me to modify the server role.
Thankfully I can edit smb.conf directly on the archlinux box where I was
able to duplicate the issue.

Setting sever role = auto, domain logons = yes doesn't fix the TCP
thrashing and works with the SIDs already populated in LDAP.

It looks like removing "deadtime = 15" from the smb.conf prevents the
TCP
thrashing. If I set "deadtime  = 1" then the thrashing happens after 3
minutes or so.

I'll see if I can put together a conf file that isn't a disaster but
still
expresses the error.

--
Paul Klapperich

On Wed, Feb 8, 2017 at 5:05 PM, Rowland Penny via samba <
samba at lists.samba.org> wrote:
> On Wed, 8 Feb 2017 16:43:53 -0600
> Paul Klapperich via samba <samba at lists.samba.org> wrote:
>
> > Very well. Here is the affected smb.conf.
> > ------
> > [global]
> >     server min protocol = NT1
> >     server max protocol = SMB3
> >     interfaces = 127.0.0.1 10.0.0.8
> >     bind interfaces only = yes
> >     encrypt passwords = yes
> >     dns proxy = no
> >     strict locking = no
> >     oplocks = yes
> >     deadtime = 15
> >     max log size = 51200
> >     max open files = 2830016
> >     logging = file
> >     load printers = no
> >     printing = bsd
> >     printcap name = /dev/null
> >     disable spoolss = yes
> >     getwd cache = yes
> >     guest account = nobody
> >     map to guest = Bad User
> >     obey pam restrictions = yes
> >     directory name cache size = 0
> >     kernel change notify = no
> >     panic action = /usr/local/libexec/samba/samba-backtrace
> >     nsupdate command = /usr/local/bin/samba-nsupdate -g
> >     server string = backup of files
> >     ea support = yes
> >     store dos attributes = yes
> >     lm announce = yes
> >     hostname lookups = yes
> >     unix extensions = no
> >     acl allow execute always = true
> >     dos filemode = yes
> >     multicast dns register = no
> >     local master = no
> >     idmap config *: backend = tdb
> >     idmap config *: range = 10000-90000
> >     server role = member server
> >     security = user
> >     passdb backend = ldapsam:ldap://ldap0.packetdigital.com
> >     ldap admin dn = cn=admin,dc=packetdigital,dc=com
> >     ldap suffix = dc=packetdigital,dc=com
> >     ldap user suffix = ou=Users
> >     ldap group suffix = ou=Groups
> >     ldap ssl = off
> >     ldap replication sleep = 1000
> >     ldap passwd sync = yes
> >     ldapsam:trusted = yes
> >     netbios name = HAMMER
> >     workgroup = PACKETDIGITAL
> >     domain logons = yes
> >     idmap config PACKETDIGITAL: backend = ldap
> >     idmap config PACKETDIGITAL: range = 10000-90000
> >     idmap config PACKETDIGITAL: ldap url = ldap0.packetdigital.com
> >     pid directory = /var/run/samba
> >     create mask = 0666
> >     directory mask = 0777
> >     client ntlmv2 auth = yes
> >     dos charset = CP437
> >     unix charset = UTF-8
> >     log level = 1
> >     #map unix users to 1 or more names
> >     ## can map an @group to a username
> >     #username map = /mnt/storage/configs/samba_users.map
> >     follow symlinks = yes
> >     wide links = yes
> >     unix extensions = no
> >     create mask = 0660
> >     idmap uid = 10000-90000
> >     idmap gid = 10000-90000
> >
> >
> > [Software]
> >     path = /mnt/storage/cifs-share/Software
> >     printable = no
> >     veto files = /.snapshot/.windows/.mac/.zfs/
> >     writeable = yes
> >     browseable = yes
> >     vfs objects = zfs_space zfsacl
> >     hide dot files = yes
> >     guest ok = no
> >     nfs4:mode = special
> >     nfs4:acedup = merge
> >     nfs4:chown = true
> >     zfsacl:acesort = dontcare
> >     create mask = 0775
> >     force create mode = 0775
> >     directory mask = 0775
> >     force directory mode = 0775
> >     force group = Software
> >     valid users = @Software, @Software-RO
> >     read only = yes
> >     write list = @Software
> >
>
> I think you need to go and read 'man smb.conf'
>
> 'server role = member server' means it should be joined to a
windows
> domain, but 'domain logons = yes' makes it a PDC, so which is it ?
>
> Rowland
>
> --
> To unsubscribe from this list go to the following URL and read the
> instructions:  https://lists.samba.org/mailman/options/samba
>

Well that was easier than I thought. Here's the default config provided by
archlinux's samba package, but with "deadtime = 1" included. With
this
config, shares mounted via mount.cifs thrash on port 445 after a few
minutes. I think the reconnect logic in the kernel's CIFS client is broken.
Should I report this on the kernel mailing list?

-----
# This is the main Samba configuration file. You should read the
# smb.conf(5) manual page in order to understand the options listed
# here. Samba has a huge number of configurable options (perhaps too
# many!) most of which are not shown in this example
#
# Any line which starts with a ; (semi-colon) or a # (hash)
# is a comment and is ignored. In this example we will use a #
# for commentry and a ; for parts of the config file that you
# may wish to enable
#
# NOTE: Whenever you modify this file you should run the command
"testparm"
# to check that you have not made any basic syntactic errors.
#
#======================= Global Settings
====================================[global]

# workgroup = NT-Domain-Name or Workgroup-Name
   workgroup = MYGROUP

# server string is the equivalent of the NT Description field
   server string = Samba Server

# This option is important for security. It allows you to restrict
# connections to machines which are on your local network. The
# following example restricts access to two C class networks and
# the "loopback" interface. For more examples of the syntax see
# the smb.conf man page
;   hosts allow = 192.168.1. 192.168.2. 127.

# if you want to automatically load your printer list rather
# than setting them up individually then you'll need this
   printcap name = /etc/printcap
   load printers = yes

# It should not be necessary to spell out the print system type unless
# yours is non-standard. Currently supported print systems include:
# bsd, sysv, plp, lprng, aix, hpux, qnx
;   printing = bsd

# Uncomment this if you want a guest account, you must add this to
/etc/passwd
# otherwise the user "nobody" is used
;  guest account = pcguest

# this tells Samba to use a separate log file for each machine
# that connects
   log file = /var/log/samba/%m.log

# Put a capping on the size of the log files (in Kb).
   max log size = 50

# Security mode. Most people will want user level security. See
# security_level.txt for details.
   security = user
# Use password server option only with security = server
;   password server = <NT-Server-Name>

# Password Level allows matching of _n_ characters of the password for
# all combinations of upper and lower case.
;  username level = 8

# You may wish to use password encryption. Please read
# ENCRYPTION.txt, Win95.txt and WinNT.txt in the Samba documentation.
# Do not enable this option unless you have read those documents
;  encrypt passwords = yes
;  smb passwd file = /etc/samba/smbpasswd

# The following are needed to allow password changing from Windows to
# update the Linux sytsem password also.
# NOTE: Use these with 'encrypt passwords' and 'smb passwd file'
above.
# NOTE2: You do NOT need these to allow workstations to change only
#        the encrypted SMB passwords. They allow the Unix password
#        to be kept in sync with the SMB password.
;  unix password sync = Yes
;  passwd program = /usr/bin/passwd %u
;  passwd chat = *New*UNIX*password* %n\n *ReType*new*UNIX*password* %n\n
*passwd:*all*authentication*tokens*updated*successfully*

# Unix users can map to different SMB User names
;  username map = /etc/samba/smbusers

# Using the following line enables you to customise your configuration
# on a per machine basis. The %m gets replaced with the netbios name
# of the machine that is connecting
;   include = /etc/samba/smb.conf.%m

# Configure Samba to use multiple interfaces
# If you have multiple network interfaces then you must list them
# here. See the man page for details.
;   interfaces = 192.168.12.2/24 192.168.13.2/24

# Configure remote browse list synchronisation here
#  request announcement to, or browse list sync from:
# a specific host or from / to a whole subnet (see below)
;   remote browse sync = 192.168.3.25 192.168.5.255
# Cause this host to announce itself to local subnets here
;   remote announce = 192.168.1.255 192.168.2.44

# Browser Control Options:
# set local master to no if you don't want Samba to become a master
# browser on your network. Otherwise the normal election rules apply
;   local master = no

# OS Level determines the precedence of this server in master browser
# elections. The default value should be reasonable
;   os level = 33

# Domain Master specifies Samba to be the Domain Master Browser. This
# allows Samba to collate browse lists between subnets. Don't use this
# if you already have a Windows NT domain controller doing this job
;   domain master = yes

# Preferred Master causes Samba to force a local browser election on startup
# and gives it a slightly higher chance of winning the election
;   preferred master = yes

# Use only if you have an NT server on your network that has been
# configured at install time to be a primary domain controller.
;   domain controller = <NT-Domain-Controller-SMBName>

# Enable this if you want Samba to be a domain logon server for
# Windows95 workstations.
;   domain logons = yes

# if you enable domain logons then you may want a per-machine or
# per user logon script
# run a specific logon batch file per workstation (machine)
;   logon script = %m.bat
# run a specific logon batch file per username
;   logon script = %U.bat

# Where to store roving profiles (only for Win95 and WinNT)
#        %L substitutes for this servers netbios name, %U is username
#        You must uncomment the [Profiles] share below
;   logon path = \\%L\Profiles\%U

# All NetBIOS names must be resolved to IP Addresses
# 'Name Resolve Order' allows the named resolution mechanism to be
specified
# the default order is "host lmhosts wins bcast". "host"
means use the unix
# system gethostbyname() function call that will use either /etc/hosts OR
# DNS or NIS depending on the settings of /etc/host.config,
/etc/nsswitch.conf
# and the /etc/resolv.conf file. "host" therefore is system
configuration
# dependant. This parameter is most often of use to prevent DNS lookups
# in order to resolve NetBIOS names to IP Addresses. Use with care!
# The example below excludes use of name resolution for machines that are
NOT
# on the local network segment
# - OR - are not deliberately to be known via lmhosts or via WINS.
; name resolve order = wins lmhosts bcast

# Windows Internet Name Serving Support Section:
# WINS Support - Tells the NMBD component of Samba to enable it's WINS
Server
;   wins support = yes

# WINS Server - Tells the NMBD components of Samba to be a WINS Client
# Note: Samba can be either a WINS Server, or a WINS Client, but NOT both
;   wins server = w.x.y.z

# WINS Proxy - Tells Samba to answer name resolution queries on
# behalf of a non WINS capable client, for this to work there must be
# at least one WINS Server on the network. The default is NO.
;   wins proxy = yes

# DNS Proxy - tells Samba whether or not to try to resolve NetBIOS names
# via DNS nslookups. The built-in default for versions 1.9.17 is yes,
# this has been changed in version 1.9.18 to no.
   dns proxy = no

# Case Preservation can be handy - system default is _no_
# NOTE: These can be set on a per share basis
;  preserve case = no
;  short preserve case = no
# Default case is normally upper case for all DOS files
;  default case = lower
# Be very careful with case sensitivity - it can break things!
;  case sensitive = no

deadtime = 1

#============================ Share Definitions
=============================[homes]
   comment = Home Directories
   browseable = no
   writable = yes

# Un-comment the following and create the netlogon directory for Domain
Logons
; [netlogon]
;   comment = Network Logon Service
;   path = /home/netlogon
;   guest ok = yes
;   writable = no
;   share modes = no


# Un-comment the following to provide a specific roving profile share
# the default is to use the user's home directory
;[Profiles]
;    path = /home/profiles
;    browseable = no
;    guest ok = yes


# NOTE: If you have a BSD-style print system there is no need to
# specifically define each individual printer
[printers]
   comment = All Printers
   path = /var/spool/samba
   browseable = no
# Set public = yes to allow user 'guest account' to print
   guest ok = no
   writable = no
   printable = yes

# This one is useful for people to share files
;[tmp]
;   comment = Temporary file space
;   path = /tmp
;   read only = no
;   public = yes

# A publicly accessible directory, but read only, except for people in
# the "staff" group
;[public]
;   comment = Public Stuff
;   path = /home/samba
;   public = yes
;   read only = yes
;   write list = @staff

# Other examples.
#
# A private printer, usable only by fred. Spool data will be placed in
fred's
# home directory. Note that fred must have write access to the spool
directory,
# wherever it is.
;[fredsprn]
;   comment = Fred's Printer
;   valid users = fred
;   path = /homes/fred
;   printer = freds_printer
;   public = no
;   writable = no
;   printable = yes

# A private directory, usable only by fred. Note that fred requires write
# access to the directory.
;[fredsdir]
;   comment = Fred's Service
;   path = /usr/somewhere/private
;   valid users = fred
;   public = no
;   writable = yes
;   printable = no

# a service which has a different directory for each machine that connects
# this allows you to tailor configurations to incoming machines. You could
# also use the %u option to tailor it by user name.
# The %m gets replaced with the machine name that is connecting.
;[pchome]
;  comment = PC Directories
;  path = /usr/pc/%m
;  public = no
;  writable = yes

# A publicly accessible directory, read/write to all users. Note that all
files
# created in the directory by users will be owned by the default user, so
# any user with access can delete any other user's files. Obviously this
# directory must be writable by the default user. Another user could of
course
# be specified, in which case all files would be owned by that user instead.
;[public]
;   path = /usr/somewhere/else/public
;   public = yes
;   only guest = yes
;   writable = yes
;   printable = no

# The following two entries demonstrate how to share a directory so that two
# users can place files there that will be owned by the specific users. In
this
# setup, the directory should be writable by both users and should have the
# sticky bit set on it to prevent abuse. Obviously this could be extended to
# as many users as required.
;[myshare]
;   comment = Mary's and Fred's stuff
;   path = /usr/somewhere/shared
;   valid users = mary fred
;   public = no
;   writable = yes
;   printable = no
;   create mask = 0765
-----

--
Paul Klapperich

On Wed, Feb 8, 2017 at 7:56 PM, Paul Klapperich <
paul.klapperich at packetdigital.com> wrote:
> I think it should be neither. Ugh... FreeNAS UI doesn't let me disable
the
> Domain Logons setting for some reason, so I'll have to talk to them on
that
> one and it seems they have no option for me to modify the server role.
> Thankfully I can edit smb.conf directly on the archlinux box where I was
> able to duplicate the issue.
>
> Setting sever role = auto, domain logons = yes doesn't fix the TCP
> thrashing and works with the SIDs already populated in LDAP.
>
> It looks like removing "deadtime = 15" from the smb.conf prevents
the TCP
> thrashing. If I set "deadtime  = 1" then the thrashing happens
after 3
> minutes or so.
>
> I'll see if I can put together a conf file that isn't a disaster
but still
> expresses the error.
>
> --
> Paul Klapperich
>
> On Wed, Feb 8, 2017 at 5:05 PM, Rowland Penny via samba <
> samba at lists.samba.org> wrote:
>
>> On Wed, 8 Feb 2017 16:43:53 -0600
>> Paul Klapperich via samba <samba at lists.samba.org> wrote:
>>
>> > Very well. Here is the affected smb.conf.
>> > ------
>> > [global]
>> >     server min protocol = NT1
>> >     server max protocol = SMB3
>> >     interfaces = 127.0.0.1 10.0.0.8
>> >     bind interfaces only = yes
>> >     encrypt passwords = yes
>> >     dns proxy = no
>> >     strict locking = no
>> >     oplocks = yes
>> >     deadtime = 15
>> >     max log size = 51200
>> >     max open files = 2830016
>> >     logging = file
>> >     load printers = no
>> >     printing = bsd
>> >     printcap name = /dev/null
>> >     disable spoolss = yes
>> >     getwd cache = yes
>> >     guest account = nobody
>> >     map to guest = Bad User
>> >     obey pam restrictions = yes
>> >     directory name cache size = 0
>> >     kernel change notify = no
>> >     panic action = /usr/local/libexec/samba/samba-backtrace
>> >     nsupdate command = /usr/local/bin/samba-nsupdate -g
>> >     server string = backup of files
>> >     ea support = yes
>> >     store dos attributes = yes
>> >     lm announce = yes
>> >     hostname lookups = yes
>> >     unix extensions = no
>> >     acl allow execute always = true
>> >     dos filemode = yes
>> >     multicast dns register = no
>> >     local master = no
>> >     idmap config *: backend = tdb
>> >     idmap config *: range = 10000-90000
>> >     server role = member server
>> >     security = user
>> >     passdb backend = ldapsam:ldap://ldap0.packetdigital.com
>> >     ldap admin dn = cn=admin,dc=packetdigital,dc=com
>> >     ldap suffix = dc=packetdigital,dc=com
>> >     ldap user suffix = ou=Users
>> >     ldap group suffix = ou=Groups
>> >     ldap ssl = off
>> >     ldap replication sleep = 1000
>> >     ldap passwd sync = yes
>> >     ldapsam:trusted = yes
>> >     netbios name = HAMMER
>> >     workgroup = PACKETDIGITAL
>> >     domain logons = yes
>> >     idmap config PACKETDIGITAL: backend = ldap
>> >     idmap config PACKETDIGITAL: range = 10000-90000
>> >     idmap config PACKETDIGITAL: ldap url = ldap0.packetdigital.com
>> >     pid directory = /var/run/samba
>> >     create mask = 0666
>> >     directory mask = 0777
>> >     client ntlmv2 auth = yes
>> >     dos charset = CP437
>> >     unix charset = UTF-8
>> >     log level = 1
>> >     #map unix users to 1 or more names
>> >     ## can map an @group to a username
>> >     #username map = /mnt/storage/configs/samba_users.map
>> >     follow symlinks = yes
>> >     wide links = yes
>> >     unix extensions = no
>> >     create mask = 0660
>> >     idmap uid = 10000-90000
>> >     idmap gid = 10000-90000
>> >
>> >
>> > [Software]
>> >     path = /mnt/storage/cifs-share/Software
>> >     printable = no
>> >     veto files = /.snapshot/.windows/.mac/.zfs/
>> >     writeable = yes
>> >     browseable = yes
>> >     vfs objects = zfs_space zfsacl
>> >     hide dot files = yes
>> >     guest ok = no
>> >     nfs4:mode = special
>> >     nfs4:acedup = merge
>> >     nfs4:chown = true
>> >     zfsacl:acesort = dontcare
>> >     create mask = 0775
>> >     force create mode = 0775
>> >     directory mask = 0775
>> >     force directory mode = 0775
>> >     force group = Software
>> >     valid users = @Software, @Software-RO
>> >     read only = yes
>> >     write list = @Software
>> >
>>
>> I think you need to go and read 'man smb.conf'
>>
>> 'server role = member server' means it should be joined to a
windows
>> domain, but 'domain logons = yes' makes it a PDC, so which is
it ?
>>
>> Rowland
>>
>> --
>> To unsubscribe from this list go to the following URL and read the
>> instructions:  https://lists.samba.org/mailman/options/samba
>>
>
>

On Wed, 8 Feb 2017 20:15:05 -0600
Paul Klapperich via samba <samba at lists.samba.org> wrote:
> Well that was easier than I thought. Here's the default config
> provided by archlinux's samba package, but with "deadtime =
1"
> included. With this config, shares mounted via mount.cifs thrash on
> port 445 after a few minutes. I think the reconnect logic in the
> kernel's CIFS client is broken. Should I report this on the kernel
> mailing list?
> 
It doesn't seem to be a Samba bug, it seems to be a mixture of Freenas
adding the wrong lines in smb.conf and possibly a kernel bug, whether
you report this, is up to you.

Rowland