[Samba] Samba 4 + Windows XP very slow - especially noticeable with many files

Tue May 20 09:17:18 MDT 2014

Hi Petr,

I added "force user = root" to my ramdisk share (and added it to valid users
= ..).
On the XP machine I'm testing now, 1000 files of 10kb:
* with force user = root: 24s, 25s, 24s
* without it: 22s, 23s, 24s

So, unfortunately for me it doesn't make a difference. It stays very slow.

Thanks for your suggestion, though.

Regards,

Bram.

Petr MOTEJLEK wrote, on 20-5-2014 16:23:
> Hi,
> 
> I am actually seeing something very similar in another email thread (which I created) in which I am yet to provide some logs - I am not having enough time to do testing :(. I myself migrated from Samba 3 to Samba 4 just this weekend. My clients are all Windows XPs.
> 
> Could you please try adding the option force user = root to the definition of the share you are testing with? I know that this is a serious security risk, BUT for me it seems to have worked around the speed issue, although I realize that we will have to get rid of that eventually :).
> 
> Have a nice day,
> Petr MOTEJLEK
> ________________________________________
> Od: samba-bounces at lists.samba.org <samba-bounces at lists.samba.org> za uživatele Bram Matthys <syzop at vulnscan.org>
> Odesláno: 20. května 2014 15:39
> Komu: samba at lists.samba.org
> Předmět: [Samba] Samba 4 + Windows XP very slow - especially noticeable with many files
> 
> Hi,
> 
> After our upgrade from Samba 3.x to 4.1.6 we are having major
> performance issues. Today, I've been able to nail it down to a simple
> test case.
> What strikes me is that Windows XP takes about 25 seconds for one job,
> while it only costs 3 seconds on Windows 7.
> 
> I have two tests:
> 
> 1000 files of 10k each (total ~10Mb):
> * Linux on localhost or a remote host (1GE or 10GE): 5.5 seconds
> * Windows XP - Machine #1: 24.5 seconds
> * Windows XP - Machine #2: 60 sec
> * Windows 7 - Identical hardware as XP machine #1: 3 seconds
> 
> One 500MB file:
> * Expected result: 4-5 seconds on 1Gbit (100-125Mbyte/s)
> * Linux on localhost: 0.5 sec
> * Other Linux machine with 10GE connect: 0.9 sec
> * Remote Linux machine (1Gbit): 4.6 sec
> * Windows XP - Machine #1: 10.4 sec
> * Windows XP - Machine #2: 11 sec
> * Windows 7 - Identical hardware as XP machine #1: 7 sec
> 
> The setup is a Samba 4.1.6 server on a high school serving 200 - 250
> computers, (at the moment) all Windows XP clients. Server runs
> virtualized in a KVM and has a 10GE connection to the switch.
> Traffic stats: OUT: 110Mbit peak (5m avg) and 30Mbit average
> Traffic stats: IN: 20Mbit peak (5m avg) and <5Mbit average
> 
> The slower-than-usual-speed for the 500M file I can live with for now,
> but the "many small files" case is a real problem. User profiles and
> desktops are full of small files so this causes a slow login. In fact,
> when like 30 computers log in at the same time it becomes so slow it
> takes many minutes for just a 10Mb profile (some even freezing forever),
> students can't start their lesson, etc... it's quite a problem.
> Previously, with the same Windows XP clients the performance on the
> Samba 3.x server was good. Users were able to log in quickly. We had no
> issues whatsoever.
> 
> The files are served from Samba 4.1.6 on a share which points to
> 'tmpfs' storage (ramdisk).
> All clients in this test have ssd's. In case of the 500M file I copied
> the file to 'NUL' to avoid storage altogether.
> Test files .tar.gz can be found on
> http://www.vulnscan.org/tmp/samba-testcase-slow-files.tar.gz
> Test code I used was:
> echo.|time
> copy \\green\xyz\500M nul
> echo.|time
> And for the small files case:
> echo.|time
> xcopy \\green\ramdisk\10k-1000x /S/E/K/H c:\local\10k-1000x\ >nul
> echo.|time
> Explorer gives very similar timings by the way. I repeated the tests on
> all clients multiple times.
> I also tried the "100 files in 10 directories" test case to see if
> maybe the problem was many files in one directory, this made no
> difference so was ruled out.
> 
> I can provide log files on request. Sorry, I didn't want to post them
> in public. I have log level 3 ones available plus packet dumps. If
> that's not sufficient I can re-run the test case on a higher log level,
> just let me know.
> 
> I already saw a number of 'Samba 4 is slow' threads here, didn't see
> much of a resolution, though. Also makes me wonder if these are also XP.
> 
> Finally, here's my smb.conf:
> [global]
>          workgroup = XXXXXXXX
>          realm = jnet.xxxxxxxxxxxx.nl
>          netbios name = GREEN
>          server role = active directory domain controller
>          idmap_ldb:use rfc2307 = yes
>          dns forwarder = 8.8.8.8
>          netbios aliases = STATLER ATHENA THORTON
>          interfaces = jnet
>          logon script = connectu.bat
>          log file = /usr/local/samba/var/log/samba.log
>          log level = 1
>          max log size = 250000
>          debug prefix timestamp = yes
>          debug uid = yes
>          reset on zero vc = yes
> #       socket options = IPTOS_LOWDELAY TCP_NODELAY
>          socket options = IPTOS_LOWDELAY TCP_NODELAY SO_KEEPALIVE
> TCP_KEEPIDLE=120 TCP_KEEPINTVL=10 TCP_KEEPCNT=5 SO_SNDBUF=65536
> SO_RCVBUF=65536
>          kernel oplocks = no
>          kernel share modes = no
>          mangling method         = hash2
>          mangle prefix           = 6
>          lanman auth             = yes
>          time server = yes
>          admin users = admin bram root xyz fog
>          guest account = nobody
>          map to guest            = Never
>          # ON OR OFF??? (default = no)
>          winbind enum users = yes
>          winbind enum groups = yes
>          wins support            = yes
>          deadtime = 20
>          # Make wide symlinks work
>          unix extensions = no
>          wide links = yes
> 
> [ramdisk]
>          comment = "Ramdisk - for testing"
>          read only = no
>          browseable = no
>          public = no
>          guest ok = no
>          valid users = bram, xyz, zzz, admin
>          path = /data/ramdisk
> 
> 
> I already tried a number of configuration changes, like not having any
> socket options, or only LOWDELAY NODELAY, etc.. no difference (on XP at
> least).
> Also commented out various options to see if that made a difference...
> not that I could find.
> 
> Hopefully someone can help us out here. We've always been proud to use
> Samba at our school instead of Windows servers, but right now it's not
> really showing the best of it ;).
> 
> Thanks in advance, and like I said.. if I need to provide anything..
> let me know,
> 
> Bram Matthys.
> 
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-- 
Bram Matthys
Software developer/IT consultant        syzop at vulnscan.org
Website:                                  www.vulnscan.org
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