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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