iozone (download): iozone -a -g 1000M > iozone.out
IOZone gfs2 iSCSI Twin
p.s. gfs2-1 - 1Gb switch. gfs2-2 - 100Mb switch
IOZone gfs2 iSCSI Single
IOZone ext3 iSCSI Single
IOZone ext3 Local Single
IOZone all-in-one graph

dd: dd if=/dev/zero of=/vz1/tmp bs=1M count=2048

dd if=/dev/zero of=/vz1/tmp bs=1M count=2048
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 66.7526 seconds, 32.2 MB/s

dd: dd if=/dev/zero of=/dev/sdc bs=1M count=2048

2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 27.9145 seconds, 76.9 MB/s

hdparm: hdparm -tT /dev/sdb1

/dev/sdb1:
 Timing cached reads:   20420 MB in  2.00 seconds = 10230.49 MB/sec
 Timing buffered disk reads:  268 MB in  3.01 seconds =  89.07 MB/sec