[Pvfs2-users] Performance issue using kernel interface

[Rob Ross]

Hi Sebastian,

What sort of servers are these? How much memory? What network? This will 
help understand performance relative to possible peaks.

Thanks,

Rob

Sebastian Bauer wrote:
> Hi Sam,
> 
> Sam Lang wrote:
>> Can you walk through your setup and testing environment in a bit more 
>> detail?  What kind of performance numbers are you getting from the 
>> kernel interface and pvfs2 apps?  Does the performance degrade over 
>> time the longer you have the kernel mounted, or does it start off bad?
> 
> I installed the pvfs2 server on two servers playing all three roles. 
> Furthermore, there are few computers acting as clients only. Using 
> pvfs2-cp from a test computer, which is a client only, I get around 
> 10MB/s which is okay for the 100Mbit ethernet connection. But if I use 
> the cp command, I cannot measure anything, it seems to stall (however, 
> the destination file grows slowly, but not more than 2kb(!) per second 
> on average!
> 
> Copying from the pvfs2 to the client-only computer is faster, about 
> 3MB/s using kernel interface (cp command) whereas the pvfs-cp gives me 
> again about 10 MB/s.
> 
> It's different when I copy the file from one master to another master.
> Concerning the write operation, using the kernel interface, I get around 
> 9.5MB/s whereas I get 35.71 MB/s using pvfs2-cp (there is a faster 
> connection between both master installed)
> 
> I've haven't yet done long time tests, but except those 2kb/s everything 
> is acceptable in our setting.
> 
> Hope this helps. Please tell, if you need anything else to know.
> 
> Ciao,
> Sebastian
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