Slow writes to big directories
Malcolm Heath
malcolm at glassworks.co.uk
Fri Feb 16 17:55:51 GMT 2001
Here's a problem I'm seeing when using an NT client to write to a Samba
server. I have no problems using an Irix client to access the same server,
or the same NT client to an NT server.
We often work with directories containing a lot of, sometimes several
thousand, small files. As the number of files in the directory increases,
so the performance of the server worsens. Here are some figures:
500 files (total 400KB): 7 seconds = 57KB/s
1000 files (total 800KB):24 seconds = 33KB/s
6000 files (total 4800KB):683 seconds = 7KB/s
As you can see, the actual amount of data being transfered is trivial - it
seems that Samba is spending all its time dealing with directory
information. This is only a problem when writing to the server - read times
increase more or less in proportion to the amount of data being transferred.
Does anybody have any suggestions?
I have already tried a few things which have been mentioned in earlier
mails: adding IPTOS_LOWDELAY to socket options;
turning off stat cache; turning off raw writes; turning off getwd cache -
all to no avail.
I am running Samba 2.0.7 on Linux 2.2.16.
Here's my Samba configuration:
# Global parameters
[global]
interfaces =
bind interfaces only = No
security = DOMAIN
encrypt passwords = Yes
update encrypted = No
allow trusted domains = Yes
hosts equiv =
min password length = 5
map to guest = Never
null passwords = No
password server = sohdmc03
smb passwd file = /etc/samba/smbpasswd
root directory = /
passwd program = /bin/passwd
passwd chat = *new*password* %n\n *new*password* %n\n *changed*
passwd chat debug = No
username map =
password level = 0
username level = 0
unix password sync = No
restrict anonymous = No
use rhosts = No
ssl = No
ssl hosts =
ssl hosts resign =
ssl CA certDir =
ssl CA certFile =
ssl server cert =
ssl server key =
ssl client cert =
ssl client key =
ssl require clientcert = No
ssl require servercert = No
ssl ciphers =
ssl version = ssl2or3
ssl compatibility = No
debug level = 1
syslog = 1
syslog only = No
log file = /var/log/samba/%m.log
max log size = 0
debug timestamp = Yes
debug hires timestamp = No
debug pid = No
debug uid = No
protocol = NT1
read bmpx = No
read raw = Yes
write raw = Yes
nt smb support = Yes
nt pipe support = Yes
nt acl support = Yes
announce version = 4.2
announce as = NT
max mux = 50
max xmit = 65535
name resolve order = wins lmhosts host bcast
max ttl = 259200
max wins ttl = 518400
min wins ttl = 21600
time server = No
change notify timeout = 60
deadtime = 0
getwd cache = Yes
keepalive = 300
lpq cache time = 10
max disk size = 0
max open files = 10000
read prediction = No
read size = 16384
shared mem size = 1048576
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
IPTOS_LOWDELAY
stat cache size = 50
load printers = Yes
printcap name = /etc/printcap
printer driver file = /etc/samba/printers.def
strip dot = No
character set =
mangled stack = 50
stat cache = Yes
domain groups =
domain admin group =
domain guest group =
domain admin users =
domain guest users =
machine password timeout = 604800
add user script =
delete user script =
logon script =
logon path = \\%N\%U\profile
logon drive =
logon home = \\%N\%U
domain logons = No
os level = 20
lm announce = Auto
lm interval = 60
preferred master = No
local master = No
domain master = No
browse list = Yes
dns proxy = No
wins proxy = No
wins server = 195.172.40.95
wins support = No
wins hook =
kernel oplocks = Yes
ole locking compatibility = Yes
oplock break wait time = 10
smbrun = /usr/bin/smbrun
config file =
auto services =
lock directory = /var/lock/samba
default service =
message command =
dfree command =
valid chars =
remote announce =
remote browse sync =
socket address = 0.0.0.0
homedir map = auto.home
time offset = 0
unix realname = No
NIS homedir = No
source environment =
panic action =
comment =
path =
revalidate = No
username =
guest account = nobody
invalid users =
valid users =
admin users =
read list =
write list =
force user =
force group =
writeable = No
create mask = 0777
force create mode = 00
security mask = -1
force security mode = -1
directory mask = 0777
force directory mode = 00
directory security mask = -1
force directory security mode = -1
inherit permissions = No
guest only = No
guest ok = No
only user = No
hosts allow =
hosts deny =
status = Yes
max connections = 0
min print space = 0
strict sync = No
sync always = No
write cache size = 0
printable = No
postscript = No
printing = lprng
print command = lpr -r -P%p %s
lpq command = lpq -P%p
lprm command = lprm -P%p %j
lppause command =
lpresume command =
queuepause command =
queueresume command =
printer =
printer driver = NULL
printer driver location =
default case = lower
case sensitive = No
preserve case = Yes
short preserve case = Yes
mangle case = No
mangling char = ~
hide dot files = Yes
delete veto files = No
veto files =
hide files =
veto oplock files =
map system = No
map hidden = No
map archive = Yes
mangled names = Yes
mangled map =
browseable = Yes
blocking locks = Yes
fake oplocks = No
locking = Yes
oplocks = Yes
level2 oplocks = No
oplock contention limit = 2
strict locking = No
share modes = Yes
copy =
include =
preexec =
preexec close = No
postexec =
root preexec =
root preexec close = No
root postexec =
available = Yes
volume =
fstype = NTFS
set directory = No
wide links = Yes
follow symlinks = Yes
dont descend =
magic script =
magic output =
delete readonly = No
dos filetimes = No
dos filetime resolution = No
fake directory create times = No
[homes]
comment = Home Directories
writeable = Yes
browseable = No
[printers]
comment = All Printers
path = /var/spool/samba
printable = Yes
browseable = No
[usr]
comment = usr share
path = /usr
writeable = Yes
[array1]
comment = Large array 1
path = /array1
writeable = Yes
guest ok = Yes
[array2]
comment = Large array 2
path = /array2
writeable = Yes
guest ok = Yes
Thanks for your help!
Malcolm Heath
Glassworks Ltd
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