samba - Mar 2011 - Samba Tuning to increase Throughput

Hi All, 
 
I have gone through threads related to throughput issue in this list. Found few 
similar issue, but could not get the solution. 

So looking for some advice from group.
 
I am trying to use the samba to access a USB disk connected to our evaluation 
board which has xtensa core running at 400 MHz. 

Samba 3.5.x is running on the board. We are getting below throughput as tested 
with the colasoft capsa software on the client PC. 

Read:    27.9 mbps
Write :  24.5 mbps
 
Some memory  info on my system? 
# cat /proc/meminfo
MemTotal:          99788 kB
MemFree:           16872 kB
Buffers:              12 kB
Cached:            30504 kB
SwapCached:            0 kB
Active:             8880 kB
Inactive:          27952 kB
Active(anon):       6336 kB
Inactive(anon):        0 kB
Active(file):       2544 kB
Inactive(file):    27952 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:          6332 kB
Mapped:             1984 kB
Slab:              42292 kB
SReclaimable:       1868 kB
SUnreclaim:        40424 kB
PageTables:          232 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       49892 kB
Committed_AS:       9636 kB
VmallocTotal:     131007 kB
VmallocUsed:        3296 kB
VmallocChunk:     115927 kB
#
 

I was trying to find the where the bottleneck is? Initially thought issue could 
be at the USB, 

But when we tested only USB (without samba) throughput it was coming 
Read:    162.5 mbps
Write :  80 mbps
So with this it appears that some bottleneck is because of the use of samba. 
 
When I tried to access same USB disk with Linux using samba, throughput was 
more.
Read:    157.9 mbps
Write :  134.5 mbps
 
So it appears that samba is not correctly configured on my board .  
Any pointers what we should investigate in this? 
Any help would be highly appreciated?
 
Regards,
Vijay

vijay vijay wrote:
> Hi All, 
>  
> I have gone through threads related to throughput issue in this list. Found
few
> similar issue, but could not get the solution. 
> 
> So looking for some advice from group.
>  
> I am trying to use the samba to access a USB disk connected to our
evaluation
> board which has xtensa core running at 400 MHz. 
> 
> Samba 3.5.x is running on the board. We are getting below throughput as
tested
> with the colasoft capsa software on the client PC. 
> 
> Read:    27.9 mbps
> Write :  24.5 mbps
>   
> I was trying to find the where the bottleneck is? Initially thought issue
could
> be at the USB, 
> 
> But when we tested only USB (without samba) throughput it was coming 
> Read:    162.5 mbps
> Write :  80 mbps
> So with this it appears that some bottleneck is because of the use of
samba.
>  
> When I tried to access same USB disk with Linux using samba, throughput was
> more.
> Read:    157.9 mbps
> Write :  134.5 mbps
>  
> So it appears that samba is not correctly configured on my board .  
> Any pointers what we should investigate in this? 
> Any help would be highly appreciated?
With samba you are getting a read speed of 157.9mbps and the disk 
is only capable of 162.5mpbs, while with samba you can write at 134.5mpbs
and the disk is only capable of 80mpbs?

Seems like you have a problem on the client, as with samba you say
your read speed is 97% the maximum offered by the USB disk and
the write speed is 68% faster using 'samba' than when you write to
it directly (not quite sure how samba accomplishes that, but 
it IS great software, I guess!)


Can you elaborate further as to the problem?  As it seems you are saying
you have some client running at 400Mhz, (about 1/7th the speed of a
modern PC, and are only getting about 1/7th the throughput).   Seems like
the client might be a bit underpowered, or what are you saying?

FWIW -- if you need to optimize speed on a fast connection, (1Gbps), you need
to increase your TCP buffers on the linux computer and increase the TCP window
size on most windows clients -- though I note that you didn't say what
windows
client you have running on this 400MHz computer, Windows 98?  XP?

Linda