samba - Jan 2008 - printers stop working

hi!

we seem to have a weird problem with our samba server and i hope somebody can 
point me in the right direction to find the cause of this problem


setup:
smbAT02:~# uname -a
Linux smbAT02 2.6.18-5-amd64 #1 SMP Sat Dec 22 20:43:59 UTC 2007 x86_64 
GNU/Linux
.) the OS is debian stable (etch)
.) samba version is 3.0.24-6etch9
.) the server has 8GB of RAM, 2 quad core intel cpus, about 1.5 TB of user 
data and between 40 and 100 concurrent users.

we use CUPS as printing backend and in general everything is working just fine 
but since we initially installed the server about 1 month ago we had 3 
incidents where printing on one of the configured network printers 
(configured as RAW printers in cups) just stopped working. the windows 
clients just displayed an 'access denied' message. printing directly via
CUPS
worked so we figured the problem must be samba.

please take a look at this (HPCLJ4600 was working, HPCLJ4700 was not):

# smbclient \\\\smbat02\\HPCLJ4600 -U username
Password:
Domain=[FOCUS-AT-01] OS=[Unix] Server=[Samba 3.0.24]
smb: \> print /exports/samba/home/username/test.txt
putting file /exports/samba/home/username/test.txt as test.txt-9135 (2.7 kb/s) 
(average 2.7 kb/s)
smb: \> exit

# smbclient \\\\smbat02\\HPCLJ4700 -U username
Password:
Domain=[FOCUS-AT-01] OS=[Unix] Server=[Samba 3.0.24]
smb: \> print /exports/samba/home/username/test.txt
NT_STATUS_DISK_FULL opening remote file test.txt-9160

the [printers] section from smb.conf looks like this:

[printers]
        comment = Printers
        path = /tmp
        browseable = No
        printable = Yes
        guest ok = Yes

during all this there was plenty of space left on /tmp and also 
on /var/cache/samba/printing where the tdb files reside so i really don't
get
the DISK_FULL error message. 

the problem turned out to be solvable by removing or renaming the 
corresponding printer's tdb file. the funny thing is, that the tdb files
seem
completely ok:

(HPCLJ4700.tdb.bak is the one with which printing did not work)

# tdbbackup -v HPCLJ4700.tdb.bak
HPCLJ4700.tdb.bak : 1007 records

# tdbbackup -v HPCLJ4700.tdb
HPCLJ4700.tdb : 634 records

the same with a different printer:
# tdbbackup -v HPLJ9050.tdb.bak
HPLJ9050.tdb.bak : 1009 records

# tdbbackup -v HPLJ9050.tdb
HPLJ9050.tdb : 54 records

we are using mostly windows 2000 and some windows XP client machines.
big thanks in advance for any ideas that could help me resolve that...3 broken 
printers in about a month is really not too good.

are there any limits on filesizes or maximum records that can be in a 
printer's tdb file? any other ideas what could have caused this?

-- 
best rgds, armin walland

focus market research
IT :: development, administration

for the search engines; we have found what the problem was.

there is a parameter called "max print jobs" which is 1000 by default
so as
soon as the number of print jobs exceeds 1000 samba won't let users print 
anymore.

we have so far not definitely found the reason why the number of jobs in the 
tdb file keeps rising but we believe it might be some sort of locking problem 
so that when clients (such as badly programmed *&%*$ access programs) send a
large number of print jobs very rapidly the smbd cannot remove finished print 
jobs from the tdb file (fast enough? or because it is locked and the 
remove-requests time out?) causing it to fill up over time.

so far we decided to set "max print jobs" to something reasonable
large and
use a weekly or monthly cronjob to remove /var/cache/samba/printing/*.tdb and 
reload smbd.

cheers! :)

-- 
best rgds, armin walland

focus market research
IT :: development, administration
http://www.focusmr.com
maculangasse 8
1220 wien
+43 (0)1-258 97 01 291

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