[Pkg-samba-maint] Bug#682921: samba: slow samba performance (both network and disk)

[Florin Iucha]

Package: samba
Version: 2:3.6.6-2
Severity: important

Dear Maintainer,

Context:  I have a workstation W (running Windows 7 Professional 64 bit)
and a server S running Debian GNU/Linux 64 bit).  The workstation is a
6-core Xeon, the server is a 4-core i7, both with hyperthreading.  The
workstation has 12GB of RAM, the server has 16.  The workstation has
on-board dual Intel gigabit Ethernet controllers (with Jumbo frames
enabled, IP checksum offload, TCP checksum offload, ...). The server
has dual Marvell SysKonnect gigabit Ethernet controllers (with Jumbo
frames enabled, IP checksum offload, TCP checksum offload, ...). They
are connected via a Cisco SG300-10 managed gigabit switch with Jumbo
frames enabled.

I have installed a fresh copy of Debian wheezy (kernel 3.2.0, samba
3.6.0).  On the system hard drive (Samsung 1TB, 7200 RPM) I have created
two logical volumes, formatted one with XFS (or ext4) and one exported
through iSCSI.

iperf with 128KB window on the Linux side and 1024KB window and 1024KB
length of buffer to send determines the speed to be 801mbit/second.

Importing the iSCSI partition on Windows, formatting it with NTFS,
then copying 11GB (basically tarring up C:\Program Files using 7-zip,
no compression) and monitoring the performance with 'dstat 5' on Linux
produces a steady stream of network receives and disk writes at 75-79
MBytes/second.

Connecting the mounted filesystem that is exported via Samba and writing
the same test file produces network receive rates that fluctuate between
21 MBytes/s and 51 MBytes/s (but clustered around 35-43 MBytes/s)
The disk writes are also interesting, as they go between 2.5KBytes/s
to 136MBytes/s.

Other than the test, the boxes are completely idle.

The only changes to the [global] section in smb.conf are:

   socket options = TCP_NODELAY SO_RCVBUF=131072 SO_SNDBUF=131072
   min receivefile size = 16384

Thank you,
florin

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-3-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages samba depends on:
ii  adduser                3.113+nmu3
ii  debconf [debconf-2.0]  1.5.44
ii  dpkg                   1.16.4.3
ii  libacl1                2.2.51-8
ii  libattr1               1:2.4.46-8
ii  libc6                  2.13-33
ii  libcap2                1:2.22-1
ii  libcomerr2             1.42.4-3
ii  libcups2               1.5.3-1
ii  libgssapi-krb5-2       1.10.1+dfsg-1
ii  libk5crypto3           1.10.1+dfsg-1
ii  libkrb5-3              1.10.1+dfsg-1
ii  libldap-2.4-2          2.4.31-1
ii  libpam-modules         1.1.3-7.1
ii  libpam-runtime         1.1.3-7.1
ii  libpam0g               1.1.3-7.1
ii  libpopt0               1.16-7
ii  libtalloc2             2.0.7+git20120207-1
ii  libtdb1                1.2.10-2
ii  libwbclient0           2:3.6.6-2
ii  lsb-base               4.1+Debian7
ii  procps                 1:3.3.3-2
ii  samba-common           2:3.6.6-2
ii  update-inetd           4.43
ii  zlib1g                 1:1.2.7.dfsg-13

Versions of packages samba recommends:
ii  logrotate  3.8.1-4
ii  tdb-tools  1.2.10-2

Versions of packages samba suggests:
ii  ctdb                              1.12+git20120201-3
pn  ldb-tools                         <none>
pn  openbsd-inetd | inet-superserver  <none>
pn  smbldap-tools                     <none>

-- debconf information:
  samba/run_mode: daemons
  samba-common/title: