On Tue, Jul 30, 2013 at 02:26:42AM -0500, Stan Hoeppner wrote: > I went to the site to subscribe again and ended up watching some of > Jeremy's Google interviews. I particularly enjoyed the interview with > James and the bow tie lesson at the end. :) > > So anyway, I recently upgraded my home network to end-to-end GbE. My > clients are Windows XP SP3 w/hot fixes, and my Samba server is 3.5.6 > atop vanilla kernel.org Linux 3.2.6 and Debian 6.0.6. > > With FDX fast ethernet steady SMB throughput was ~8.5MB/s. FTP and HTTP > throughput were ~11.5MB/s. With GbE steady SMB throughput is ~23MB/s, > nearly a 3x improvement, making large file copies such as ISOs much > speedier. However ProFTPd and Lighttpd throughput are both a steady > ~48MB/s, just over double the SMB throughput. > > I've tweaked the various Windows TCP stack registry settings, > WindowScaling ON, Timestamps OFF, 256KB TcpWindowSize, etc. Between two > Windows machines SMB throughput is ~45MB/s. You can see from the > remarks below the various smb.conf options I've tried. No tweaking thus > far of either Windows or Samba has yielded any improvement, at all. It > seems that regardless of tweaking I'm stuck at ~23MB/s. > > [global] > # max xmit=65536 > # socket options=TCP_NODELAY IPTOS_LOWDELAY > # read raw=yes > # large readwrite=yes > # aio read size=8192 > nt acl support=no > fstype=Samba > client signing=disabled > smb encrypt=disabled > # smb ports=139 > smb ports=445 > > The Linux server has an Intel PRO/1000GT NIC, the clients motherboard > embedded RealTek 8111/8169, the latter being the reason I'm limited to > ~50MB/s over the wire. > > I run nmbd via the standard init script at startup but I run smbd via > inetd. This doesn't appear to affect throughput. I effect config > changes with kill -HUP of inetd and killing smbd. > > I have Wireshark installed on one of the Windows XP machines, though I'm > a complete novice with it. I assume a packet trace may be necessary to > figure out where the SMB request/reply latency is hiding. > > ~23MB/s is a marked improvement and I'm not intending to complain here. > It just seems rather low given FTP/HTTP throughput. I'm wondering how > much of that ~48MB/s I'm leaving on the table, that could be coaxed out > of Windows or smbd, the kernel, etc with some tweaking.
The main question is -- does your client issue multiple requests in parallel? If not, you are effectively limited to a TCP Window size of roughly 60k, because the higher level only issues requests of that size sequentially. If you have a properly multi-threaded or async copy program on the client, I think even XP would be able to do multi-issue. With newer clients like Windows 7 the situation is even better: The SMB2 client is a lot better performance-wise than XP ever was. With best regards, Volker Lendecke -- SerNet GmbH, Bahnhofsallee 1b, 37081 Göttingen phone: +49-551-370000-0, fax: +49-551-370000-9 AG Göttingen, HRB 2816, GF: Dr. Johannes Loxen http://www.sernet.de, mailto:kont...@sernet.de -- To unsubscribe from this list go to the following URL and read the instructions: https://lists.samba.org/mailman/options/samba
