Slow Mappings with NIS and large groups

Lee Cashmore lee.cashmore at
Sun Sep 24 12:53:48 GMT 2000

Does anyone have any experiance of these problems

OS Redhat 6.2
Samba version 2.0.7

Machine runs a slave NIS server and has 2 sets of groups one for staff and 
one for students e.g.


Student groups follow the same format but are groups  stud0 to stud9

all the groups for each user are correctly reported by linux and I can find 
no other problems and logon speed under linux is fine. The problem we have 
is that we have upto 550 pc's mapping to a share which runs off this box 
(Details of share below). All the main logons happen within a short period 
of time i.e. when the students login in a morning and after breaks, for 
some reason it is taking a long time for any windows NT machine to map a 
drive to this particular share.

Samba is doing Domain Authentication and after doing various amounts of 
testing and debuging I can find no way of improving the speed of the drive 
mapping process. We are thus experiancing 2 problems, firstly a lot of the 
drive mappings will fail (with a 240 error) when lots of people are logging 
on and secondly the box is put under so much load due to the exessive 
amounts of time samba spends checking against the groups. If I copy the 
password, shadow and group files off the primary nis server and put them on 
the local machine the drive mappings are almost immediate. We presently 
have 1000 or so students in the groups and this will double if not tripple 
by the end of the year, There are also around 300 staff accounts.

This share is a specific one which allows students Read only access and 
staff read/write access. the files in the share are owned by the user/group 
shares/shares respectivly.

Any help or ideas would be greatly appreciated

Lee Cashmore

P.S. Relavant sections of configs and log files listed below

Share config from smb.conf

    comment = Staff/Student Share
    path = /var/exports/qdrive
    browseable = yes
    writable = yes
    available = yes
    public = no
    admin users = leec
    read list = +staff0, +staff1, +staff2, +staff3, +staff4, +stud0, 
+stud1, +stud2, +stud3, +stud4, +stud5, +stud6, +stud7, +stud8, +stud9
    valid users = +staff0, +staff1, +staff2, +staff3, +staff4, +stud0, 
+stud1, +stud2, +stud3, +stud4, +stud5, +stud6, +stud7, +stud8, +stud9
    write list = +staff0, +staff1, +staff2, +staff3, +staff4
    force user = shares
    force group = shares
    force create mode = 770
    force directory mode = 770

Section of Log file of NT 4 Wks Mapping to the samba server

[2000/09/24 13:10:19.810779, 5] lib/util.c:show_msg(446)
[2000/09/24 13:10:19.810825, 10] lib/util.c:dump_data(2918)
  [000] 00 5C 5C 49 4E 54 52 41  4E 45 54 5C 51 44 52 49  .\\INTRA NET\QDRI
[2000/09/24 13:10:19.810925, 10] lib/util.c:dump_data(2926)
  [010] 56 45 00 41 3A 00                                 VE.A:.
[2000/09/24 13:10:19.811011, 3] smbd/process.c:switch_message(448)
  switch message SMBtconX (pid 15697)
[2000/09/24 13:10:19.811075, 4] smbd/reply.c:reply_tcon_and_X(311)
  Got device type A:		
[2000/09/24 13:10:27.032062, 3] smbd/password.c:authorise_login(759)
  ACCEPTED: validated uid ok as non-guest  <<------- PROBLEM HERE TIME DIFF 
OF 8 seconds ???
[2000/09/24 13:10:28.810178, 3] smbd/service.c:make_connection(380)
  Forced user shares
[2000/09/24 13:10:28.810741, 3] smbd/service.c:make_connection(428)
  Forced group shares
[2000/09/24 13:10:28.810813, 3] smbd/service.c:make_connection(441)
  Connect path is /var/exports/qdrive
[2000/09/24 13:10:28.869361, 3] smbd/password.c:setup_groups(192)
  shares is in 1 groups: 1004
[2000/09/24 13:10:28.869495, 5] smbd/connection.c:claim_connection(137)
  trying claim /var/lock/samba STATUS. 100000
[2000/09/24 13:10:28.869607, 8] lib/util.c:fcntl_lock(2672)

Lee Cashmore                              Telephone : +44 (0)1952 642286
Network Administrator (Postmaster)
Telford College of Arts & Technology    Web Site :

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