[Samba] smbd eating up 80+% of cpu on simple transactions :(

Don samba at geeksrus.ca
Thu Jun 16 04:07:17 GMT 2005


First, my apologies for being a samba "newbie"... its not that I'm new 
to samba, its just that it has always "just worked for me" and so I'm 
very new to trying to debug it... after having used it for 5 years.

I have a new server - its a Xeon 2.8GHz.  I have mounted on it a VTrak 
12110 RAID system with a 1.5T partition on it.  I've installed FC3 out 
of the box.  I've configured samba pretty much as I have always 
configured samba on my previous RH7.3 and FC1 boxes.    The problem is 
that requests for files are often deathly slow (from 15s to 2 minutes) 
and when I make such an access, I can see on "top" the the cpu usage for 
the machine goes up to over 80% - being used by an "smbd" process.  Even 
when there are no requests going on, there is just a window open on the 
client, the associated smbd process sometime use from 16 to 40% of the 
cpu.  NFS mounts of the same drives do not have this problem.

This is being used as a file server for a WindowsXP office.  Right now I 
only have 3 real users on this system, so its pretty light.

I've seen some discussion on this list (re: "Horrendously slow...").  
I've  tried "yum update" to the samba 3.0.10 rpms.  Now I've downloaded 
and installed the srpms for 3.0.14a.  The behaviour is still there.  
I've tried to enable wins on the samba server with no change.

I admit that there is a lot of reading I can do to try to further my 
understanding of how to figure this out... and I'm doing so.   Its just 
that never having taken this leap before I'm struggling a bit with where 
to start.

Does this problem sound familiar to anyone?  Does anyone have some 
suggestions for first avenues to investigate?

Incidentally - the problem could be in the RAID drive - its new and 
unproven.

Any advice welcome - I'm pretty frustrated at the moment.  I'm attaching 
my smb.conf file... what else can I provide?

Thanks,
Don

-------------- next part --------------
# 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]

log level = 10

# DON
#netbios aliases = fs3 workfs
	netbios aliases = fs3 work2fs

# 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 = cups

# This option tells cups that the data has already been rasterized
	cups options = raw

# 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
# all log information in one file
#   log file = /var/log/samba/smbd.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.
# 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.
;  password level = 8
;  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
	smb passwd file = /usr/local/samba/private/smbpasswd

# The following are needed to allow password changing from Windows to
# update the Linux system 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

# Most people will find that this option gives better performance.
# See speed.txt and the manual pages for details
	socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192

# 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

# 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.
# DON
 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
# DON
   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
# DON - turned on June 15, 2005
	preserve case = yes
	short preserve case = yes
# 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

#============================ Share Definitions ==============================
	idmap uid = 16777216-33554431
	idmap gid = 16777216-33554431
	template shell = /bin/false
	username map = /etc/samba/smbusers
	password server = None
	winbind use default domain = no

# Examples taken from fs2
#[homes]
#   comment = Home Directories
#   browseable = no
#   writable = yes
#   valid users = %S
#   create mode = 0664
#   directory mode = 0775
# If you want users samba doesn't recognize to be mapped to a guest user
; map to guest = bad user

#[project]
#   comment = Project Disk
#   path = /project
#   public = yes
#   writable = yes
#   printable = no
#   create mode = 0664
#   directory mode = 0775

[project-bad]
	comment = Project Disk
	path = /promiseraid/1/project
	guest ok = yes
	printable = no
	create mask = 0664
	directory mask = 0775



[work2]
	comment = Work2 Disk - NO BACK UP
	path = /work/work2
	guest ok = yes
	writeable = yes
	printable = no
	dos filetime resolution = True

[work3]
	comment = Work3 Disk - NO BACK UP
	path = /work3
	guest ok = yes
	writeable = yes
	printable = no
	dos filetime resolution = True




# 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
	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




More information about the samba mailing list