[Linux-cluster] what's gfs_scand doing?

[孙俊伟]

Hi,all

I got the gfs' code from cvs on 2004-12-12, which was for kernel 2.6.9, and the OS was FC3.
I created three logic volumes by CLVM, then I test the read performance of the SAN storage.
On one node, I got 150MB/s by reading 50 files on one LV concurrently; But when I readed 
the same 50 files on two nodes started at the same time, the result was 21 + 21 and totally
42 MB/s. So why the performance declined two much? I saw the result of command "top", the 
process "gfs_scand" got the No.1, so what's gfs_scand doing? And iowait got much cpu's idle
time. Is it related to hardwares, such as the RAID controller, the HBA card, and the FC 
switch? Or related to hardware drivers?

Thanks for any reply!
Best regards! 
Luckey