[Samba] How Samba let us down
tims at cqpl.com.au
Wed Oct 23 06:27:01 GMT 2002
err are you asking for help, or just wasting our time?
sounds like you have a big job ahead of you tonight setting up that NT
machine better get that out of the way before telling us your life story
----- Original Message -----
From: "Chris de Vidal" <cdevidal at yahoo.com>
To: <samba at lists.samba.org>
Cc: <samba-technical at lists.samba.org>
Sent: Wednesday, October 23, 2002 4:13 PM
Subject: [Samba] How Samba let us down
> Before you read this, I want to state (for reasons
> listed below) that I don't expect an answer (advice is
> welcomed, but please read this email carefully before
> answering). I'm sharing this with the community with
> the hope that better software results from our sad
> I've been using NT for 4 years, Netware and Linux for
> 3 years, and Samba for almost 2. I work in the IT
> department of a medium-sized unit of a global
> advertising company. We have a Netware and NT
> environment with a bit of Linux.
> We installed a 280GB IDE Samba archive server (rare
> usage) and a 15GB SCSI Mac/Samba file server (medium
> usage). We also use Samba for more menial tasks like
> smbmounts and file transfers. We thought we were
> comfortable with Samba. We knew we were comfortable
> with other types of file servers.
> OUR SETUP
> Going from my tired memory:
> Athlon MP 1.8GHz (mem=nopentium)
> 2GB ECC SDRAM
> Tyan S2460(I think?)
> Antec 450W PS
> Lots of cooling
> 5 IBM DeskStar 120GB drives with 8MB caches in RAID 5
> 3ware 7580(I think?) 8-port hardware RAID
> 3ware hot-swappable drive cages
> Intel e1000 Gigabit NIC, full duplex, 1000MBit,
> autonegotiation off
> 3com Gigabit switch, autonegotiation off
> RedHat 7.3
> Kernel 2.4.19 with ACL support
> ext3 with ACL support
> Samba 2.2.5 with ACL support installed from a
> recompiled SRPM from the samba.org FTP site.
> NO nfs daemon (I hear it's buggy w/ ACLs)
> We have a variety of clients, from DOS and OS/2 to
> Windows (9x-2000) and Linux. The server acts as a
> print spooling area (the actual queues are on an NT
> server) and scratch area for database programmers to
> manipulate their flat database files. As far as I
> know, these files are not commonly accessed by more
> than one user at a time.
> THE PROBLEM
> For the past year, our heaviest-used Netware server
> has been under more and more stress.. filling up,
> running out of licenses, slowing down, etc.
> Preliminary tests using Samba on a fast Linux box
> showed anywhere from 70% to 1000% speed improvements,
> depending on the task. The decision was made to
> switch it to Linux; the whole company is migrating
> away from Netware and we (as a unit, not speaking for
> the company) don't want to be completely trapped into
> Windows if we can help it.
> The new hardware arrived and more preliminary tests
> indicated all looked good. We were set to switch last
> Saturday night. We turned off logins to the Netware
> box, backed it up, restored it to the new Linux box,
> set permissions, then made sure the various computers
> in the building could log in.
> Yesterday, our first day, was rough. For most of the
> day we fought random slow browsing with no
> explanation. Clients would appear to lock up for
> several seconds. We found some misconfigurations in
> smb.conf but the problems reappeared. No errors were
> seen in any machines' logs on debug level 2. I
> trimmed the smb.conf to a minimal number of options
> and that seemed to help with the slowness. Today,
> however, the problem reappeared a few times with no
> errors in the logs that we could see.
> The printers were missing some of the records sent to
> them to print, something that had never happened with
> Netware. Every time the missing records were
> different. Occasionally, it would work right.
> Oplocks (kernel, level I and II) were left to defaults
> (turned on).
> THE OUTCOME
> Sadly, tonight we are installing a Windows NT server.
> Installing a brand new server is actually cheaper for
> us than the 8 or so hours of downtime to back up the
> server, install NT on it, and restore the data to it.
> We don't want to revert to Netware because so many
> clients have been reconfigured to log on only to the
> domain (DOS, OS/2, etc.) and that would require many
> more hours reversing those changes. Also, some files
> have been added since leaving Netware. We also
> decided to proceed to use NT because is more proven in
> this capacity.
> To be fair, the problems could be related to some
> misconfiguration. I have pasted the smb.conf below.
> I fear it might just be an oplock problem, but it is
> not clear what would result if more than one user
> happened to try to write to a file with them disabled.
> Every advice we found said to leave them on to
> prevent corruption and to improve performance. We ran
> out of time to test it, and feared what failure would
> bring. Running this:
> grep -r -B5 -A5 oplock /var/log/samba/ | grep -B5 -A5
> produced only 5 of these errors
> oplock_break: receive_smb error (Connection reset by
> from the same DOS machine from 2 days worth of all
> machines' logs running at debuglevel 1 (some at level
> 2). I don't know if that is a good indicator of an
> oplock problem. I can do other greps on request.
> Unfortunately, we can't test out your suggestions in
> production, and our off-production testing apparently
> can't stress it well enough. So please just take this
> email as input - I'm not looking for answers here,
> though advice is appreciated.
> The problem could also have been environment or
> hardware. We should know soon, as we are going to
> reinstall the original Samba server with NT, and the
> problems should reappear if hardware or environment.
> If we do find that to be true, I will certainly reveal
> our findings to this mailing list.
> And perhaps the problem was with ACLs. We couldn't
> turn them off in production to test that theory.
> It is likely that we will try Samba in this capacity
> again in the future with a more mature version.
> Thanks for listening,
> server string =
> workgroup = <our domain>
> password server = <our PDC>
> security = domain
> encrypt passwords = yes
> smb passwd file =
> veto files = /lost+found/
> winbind uid = 10000-20000
> winbind gid = 10000-20000
> winbind separator = +
> create mask = 660
> force create mode = 660
> directory mask = 0770
> force directory mode = 0770
> log file =
> debuglevel = 2
> path = /share/print
> writeable = yes
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