[Gluster-users] No linear scaling

[Jon Tegner]

Hi,



I'm only recently started playing with glusterfs. My set up consists of
two servers (noriko and kumiko), each with twelve 1Tb disk, raided
together in raid10.




The systems have CentOS-5.5 installed, and I have
installed glusterfs-3.0.4-1 (client, common and server).




I have generated the server and client files with:




glusterfs-volgen --name store1 --transport tcp noriko:/mnt/raid10/
kumiko:/mnt/raid10




I then mounted the filesystem with:




glusterfs --volfile=/etc/glusterfs/store1-tcp.vol /mnt/glusterfs




In a naive test of the performance I tried:




dd if=largeFile of=copyOfLargeFile bs=1024k oflag=sync




(largeFile is about 450 M)




I did this first from one client, and then from two clients
simultaneously. I expected the time to be about the same for the two
cases, but in contrast it took about twice the time when doing the
operation simultaneously. I'm probably missing something obvious here,
and would appreciate any help.




Regards,




/jon