Redhat specific...

I understand that disks have a higher throughput when reading/writing data from/to the edge of a drive's platter. So when I partition a virgin disk, which one will be on the edge?

Or better yet, which sector is closest to the edge? 0 or n?

I don't know of any good way to determine the physical location of a particular sector or partition on a disk. I'm sure it depends greatly on the size (in MB) of your drive, the number of platters used, manufacturer, and a dozen other things. I would be surprised if there existed a significant difference in I/O speed between the inner and outer edges, though.

It used to be the case that the "cylinders" in a disk were numbered from the inside towards the outside, so cylinder n, rather than 0, would be the outermost. But I think that's all handled logically now, and doesn't really reflect the physical structure of the disk.

bah...

thanks though...

it is logically handled, but it's orderly.
the lower the cylinder number, the closer to the outside.
the outside is faster than the inside.

notice my /dev/hda3 is at the end of the disk. ( the inside cylinders)

/# fdisk -l
Disk /dev/hda: 255 heads, 63 sectors, 9964 cylinders
Units = cylinders of 16065 * 512 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 260 2088418+ 6 FAT16
/dev/hda2 1000 2500 12056782+ c Win95 FAT32 (LBA)
/dev/hda3 7501 9964 19792080 83 Linux
/dev/hda4 2501 7500 40162500 85 Linux extended
/dev/hda5 2501 3200 5622718+ 83 Linux
/dev/hda6 3201 3400 1606468+ 83 Linux
/dev/hda7 3401 3600 1606468+ 83 Linux
/dev/hda8 3601 4300 5622718+ 83 Linux
/dev/hda9 4301 4400 803218+ 82 Linux swap
/dev/hda10 4401 7500 24900718+ 83 Linux
Partition table entries are not in disk order


/# for i in 1 2 3 5 6 7 8 9 10; do hdparm -t /dev/hda$i; done
/dev/hda1:
Timing buffered disk reads: 64 MB in 1.35 seconds = 47.41 MB/sec
/dev/hda2:
Timing buffered disk reads: 64 MB in 1.35 seconds = 47.41 MB/sec
/dev/hda3:
Timing buffered disk reads: 64 MB in 1.76 seconds = 36.36 MB/sec
/dev/hda5:
Timing buffered disk reads: 64 MB in 1.41 seconds = 45.39 MB/sec
/dev/hda6:
Timing buffered disk reads: 64 MB in 1.43 seconds = 44.76 MB/sec
/dev/hda7:
Timing buffered disk reads: 64 MB in 1.44 seconds = 44.44 MB/sec
/dev/hda8:
Timing buffered disk reads: 64 MB in 1.47 seconds = 43.54 MB/sec
/dev/hda9:
Timing buffered disk reads: 64 MB in 1.52 seconds = 42.11 MB/sec
/dev/hda10:
Timing buffered disk reads: 64 MB in 1.52 seconds = 42.11 MB/sec
/#

ahsoh! This is what I thought...

you da man... thanks!