[Samba] Performance issue with Vista

[Jeremy Allison]

On Thu, Feb 22, 2007 at 03:44:56PM +0200, Mikko Pukki wrote:
> Hi,
> 
> I tested a little bit Samba with Windows vista and found serious performance issue regarding reading large files from Samba server. Computers that I tested Samba with were all identical computers equipped with 2,8 GHz Pentium D processors, 1 GB memory and 1 Gbit/s LAN. All computers have only external USB hard drives so that it is easier to change from operating system to another.
> 
> First I tested performance with 160 MB tar.gz file and there were no problems. SMBClient from another Linux computer reads and writes about 45 MB/s. Performance on Vista Client was higher than this. Write was just a little bit under 50 MB/s and read 48 MB/s. Then I moved to larger files to make sure that I would get results that simulate better the environment, where I need Samba myself (Saving and reading 500-1000 MB images from and to Photoshop)
> . I chose 690MB Knoppix image. Read and write from SMBclient were 27 to 28 MB/s at average. Writing from Vista bursts at 50 MB/s and minimum was 28 MB/s leading to over 30 MB/s average. _Then to the problem_: Reading from Samba share gave bursts of 6 MB/s and repeated drops to 0,5 MB/s.
> 
> I have same kind of problem also at home (at the moment 100 MB/s network) using same version of samba and nearly identical configuration file. SMBClient reads and writes ok but performance from Windows XP is poor (but in this case both reading and writing)
> 
> Has anyone else encountered same behaviour and is there any workarounds for this. Linux systems that I use are Debian Sarge 3.1r5 and Samba version is 3.0.14a-3s.

We've done some work on this for 3.0.25 - check out the new
vfs_readahead module.

Jeremy.