[PVFS2-users] Re: PVFS2 vs. NFS performance

[Robert Latham]

On Tue, Jun 29, 2004 at 08:21:05AM -0700, Charles Shen wrote:
> Overjoyed with successful PVFS2 installation, I decided to run some
> simple test to compare it with NFS. My machines are PCs with 2.6 GHz
> Celeron CPU, 512 MB memory, 100 Mb Ethernet connection, and Fedora
> Core 2. I used Linux "dd" command for file read and write, and
> "time" for duration. The file size is 1GB to avoid files being
> cached.


> Apparently with the single client test conditions, PVFS2 is much slower 
> than NFS,
> 30% for write, and 65% for read.

Two factors here:  dd isn't very kind to PVFS until the block size
reaches 1MB or more, and NFS is much more agressive with caching than
PVFS2 is.  

> I know PVFS2 is for parallel computing. But, is there anything I can
> do to make it run
> faster in my setup?  

Use a bigger block size for dd and see if that makes things better.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Labs, IL USA                B29D F333 664A 4280 315B