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. 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