On 17 January 2011 08:14, Chris Duffy <c...@small-tree.com> wrote: > We are testing Samba 3 (and 4) on Fedora Core 13, > 10Gbit connection with a Mac OS 10.6.4 system > as the client. We will be adding some Windows > machines sooner or later with 10Gbit interfaces. > > We are seeing 100-150MBytes/sec read or write > performance between the Mac and the FC13 system > over 10Gbit interface but it should be capable of > 400-500MBytes/sec. We have a local raid > on the FC13 system that runs 1GByte/sec locally > using an Areca 1880-ix-16 raid card (6Gbit version). > It has 16 fast Hitachi disks in a Raid5 format > using xfs filesystem. > > The problem here is that samba is poking the Areca > at 128KByte I/O's on preads and writes, i.e. > shown to us using strace on the smbd daemons > that are running. Using vmstat/iostat/sar utilities, > we see 100% utilization of the Areca card because the > average wait time is real high and the average > queue length to it is also high......too many > small I/O's..... > This is not the case if I run "fio" or "dd" locally > to/from the Areca's raid using 1-4MByte I/O's. > I see fast I/O... > > I do not see any way to increase the size of Samba's > pread/write's in the smb.conf documentation. I > am sure it may be just a matter of getting the source > code and making some changes to allow larger > sized IO's but........and of course I suppose Windows > clients may complain but.... > > I remember that back in the old Irix days with the > group of engineers in Australia I worked with, > we had Samba screaming fast but not sure if they > tweaked the version of Samba on Irix to do this.
Hi Chris :) IIRC, we used a carefully tweaked read ahead module to make sure that I/Os were hitting the disks properly aligned and of reasonable size. http://www.samba.org/samba/docs/man/manpages-3/vfs_readahead.8.html > > Can you guys come up with a way for us to allow > the reads/writes to/from the disks to be tunable > up to say 4MB in size? > > Thx > chris duffy > > -- > To unsubscribe from this list go to the following URL and read the > instructions: https://lists.samba.org/mailman/options/samba > -- James Peach | jor...@gmail.com -- To unsubscribe from this list go to the following URL and read the instructions: https://lists.samba.org/mailman/options/samba