Hey David, Can you provide the qemu command to run each of them? What's your gluster/disk/network layout look like?
Depending on your disk and network setup you may be hitting a bottleneck there that would prevent gfapi from performing at capacity. Lots of options here that could impact things. ----- Original Message ----- From: "Dave Christianson" <davidchristians...@gmail.com> To: gluster-users@gluster.org Sent: Thursday, April 3, 2014 6:05:51 AM Subject: [Gluster-users] No performance difference using libgfapi? Good Morning, In my earlier experience invoking a VM using qemu/libgfapi, I reported that it was noticeably faster than the same VM invoked from libvirt using a FUSE mount; however, this was erroneous as the qemu/libgfapi-invoked image was created using 2x the RAM and cpu's... So, invoking the image using both methods using consistent specs of 2GB RAM and 2 cpu's, I attempted to check drive performance using the following commands: (For regular FUSE mount I have the gluster volume mounted at /var/lib/libvirt/images.) (For libgfapi I specify -disk file=gluster://gfs-00/gfsvol/tester1/img.) Using libvirt/FUSE mount: [root@tester1 ~]# hdparm -Tt /dev/vda1 /dev/vda1: Timing cached reads: 11346 MB in 2.00 seconds = 5681.63 MB/sec Timing buffered disk reads: 36 MB in 3.05 seconds = 11.80 MB/sec [root@tester1 ~]# dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 41943040 bytes (42MB) copied, 0.0646241 s, 649 MB/sec Using qemu/libgfapi: [root@tester1 ~]# hdparm -Tt /dev/vda1 /dev/vda1: Timing cached reads: 11998 MB in 2.00 seconds = 6008.57 MB/sec Timing buffered disk reads: 36 MB in 3.03 seconds = 11.89 MB/sec [root@tester1 ~]# dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output 10240+0 records in 10240+0 records out 41943040 bytes (42MB) copied, 0.0621412 s, 675 MB/sec Should I be seeing a bigger difference, or am I doing something wrong? I'm also curious whether people have found that the performance difference is greater as the size of the gluster cluster scales up. Thanks, David _______________________________________________ Gluster-users mailing list Gluster-users@gluster.org http://supercolony.gluster.org/mailman/listinfo/gluster-users
_______________________________________________ Gluster-users mailing list Gluster-users@gluster.org http://supercolony.gluster.org/mailman/listinfo/gluster-users
