[lug] LVM on SW raid simple tests

[Lee Woodworth]

Just some numbers to ponder

kernel = Linux version 2.6.17-gentoo-r1
md0 = raid mirror (hda7, hdc7)
vgmd0-xxx = LVM logical volume using md0 as its PV

# hdparm -t /dev/hda7
/dev/hda7:
  Timing buffered disk reads:  170 MB in  3.03 seconds =  56.20 MB/sec

# hdparm -t /dev/hdc7
/dev/hdc7:
  Timing buffered disk reads:  160 MB in  3.03 seconds =  52.80 MB/sec

# hdparm -t /dev/md0
/dev/md0:
  Timing buffered disk reads:  170 MB in  3.03 seconds =  56.08 MB/sec

# hdparm -t /dev/mapper/vgmd0-xxx
/dev/mapper/vgmd0-xxx:
  Timing buffered disk reads:  158 MB in  3.02 seconds =  52.36 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device