Re: cfdisk vs fdisk & speaking of Western Digital drives...
On Sat, Jan 03, 2004 at 04:52:06PM -0500, Andy Firman <andy@firman.us> wrote:
> First, what is the difference between fdisk and cfdisk,
> other cfdisk being curses based?
Not much, you can achieve your needs in both.
> Second, I have 2 Western Digital drives.
> Both model WD400BB but they were manufactured about
> 6 months apart.
It may be an other revision, hdd controllers can have different
chipset/'bios'. Also, they may have higher density plates, so less of
them enough for the same capacity.
> I partioned both disk's exactly the same using cfdisk
> during the install. It seems that one drive has 4863 cylinders
> and the other has 77545 cylinders.
Can be a BIOS setting, check that both drives use the same addressing
method (CHS, LBA, other).
> Why would Western Digital
> make the drives different? Or did I do something wrong
> with partitioning/formatting?
No, partitioning is ok IMHO. What you don't know that hdd size is
calculated from a triplet: Cylinders, Headers, Sectors:
> Disk Drive: /dev/hda
> Size: 40000000000 bytes
> Heads: 255 Sectors per Track: 63 Cylinders: 4863
> Disk Drive: /dev/hdd
> Size: 40020664320 bytes
> Heads: 16 Sectors per Track: 63 Cylinders: 77545
If you do the math: C*H*S*512 => you should get the size in bytes. So
hdd has more Cylinders because it has less Heads value (this is not the
real value, but some kind of mapped one).
> Do the physical drives and partitions have to be EXACTLY the
> same for RAID 1 to work properly or will the following
> layouts of my drives be sufficient?
Hmm. Note sure this is ok, try to set the same CHS for both drives.
> /dev/hda1 * 1 122 979933+ 83 Linux
Also, if I remember right, a plus sign after the size is indicating a
warning that the partition does not on Cylinder boundary, which may be a
problem as partitions may overlap a bit.
Cheers,
GCS
Off-to-sleep...
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