[Pvfs2-users] An I/O test

[Rob Ross]

Hi,

What sorts of files are you copying? What parameter values are you  
using for # of stripes, size of stripes, etc. on your PVFS volume?

Rob

On Sep 4, 2008, at 4:13 PM, hawaii wrote:

> A pvfs2 I/O test
> (for comments)
> ===================
>
> pvfs version: 2.7.1
> configuration: 1 meta server + 3 data servre. Each server has 2 cpus  
> reserved
>
> Tests: within pvfs2; from pvfs2 to local; nfs
> Use pvfs2-cp-r, pvfs2-cp-r.pl, and cp
> (thanks Mark Bartelt for providing pvfs2-cp-r and pvfs2-cp-r.pl)
>
> Source direcotry: WRF
> df -k WRF
>   lots of subdirctories
> 511868  WRF
>
> (1) pvfs2 -> pvfs2
>
> time pvfs2-cp-r WRF tmp
> real    4m16.414s
> user    0m38.385s
> sys     0m31.874s
> I/O 2 MB/s
>
> time pvfs2-cp-r.pl WRF tmp
> Copying files from "WRF" to "tmp/WRF" using pvfs2-cp
> real    4m21.573s
> user    0m38.741s
> sys     0m32.293s
> I/O 1.96 MB/s
>
> time cp -rp WRF tmp
> Lots of 0 files (unreliable)
> real    7m21.473s
> user    0m0.100s
> sys     0m5.792s
> I/O 1.16 MB/s
>
> (2) pvfs2 -> local hard drive
>
> time pvfs2-cp-r.pl /pvfs2-dir/WRF /home/user
> Copying files from "/pvfs2-dir/WRF" to "/home/user/WRF" using pvfs2-cp
> real    1m19.311s
> user    0m19.008s
> sys     0m29.327s
> I/O     6.4 MB/s
>
> time pvfs2-cp-r /pvfs2-dir/WRF /home/user
> real    1m10.739s
> user    0m20.609s
> sys     0m30.021s
> I/O     7.25 MB/s
>
> time cp -rp /pvfs2-dir/WRF /home/user
> Lots of 0 files (unreliable)
> real    1m34.071s
> user    0m0.113s
> sys     0m3.906s
> I/O     5.45 MB/s
>
> (3) cp an nfs file to local disk
> 2057207616 t.dat
> time cp -p /nfs-dir/t.dat /home/usr/.
> real    2m55.894s
> user    0m0.257s
> sys     0m6.946s
> Read 11.7 MB/s
>
> Conclusion from this test:
> (1) pvfs2-cp-r is the fastest and cp -r is the slowest
> (2) it is slower to copy directory inside pvfs2 than to local disk
> (3) I/O pvfs2 is much slower than nfs !!!
> Any comments on the results?
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