[svlug] Odd IDE disk geometry differences...

[Vince Duperron]

> 
> I just put two new Maxtor 80GB IDE disks in a newly built server
> (software RAID-1).
> 
> I notice this in /var/log/dmesg:
> 
> ---snip---
> 
> hda: MAXTOR 6L080J4, ATA DISK drive
> hdc: MAXTOR 6L080J4, ATA DISK drive
> ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> ide1 at 0x170-0x177,0x376 on irq 15
> hda: 156355584 sectors (80054 MB) w/1819KiB Cache, CHS=9732/255/63, UDMA(100)
> hdc: 156355584 sectors (80054 MB) w/1819KiB Cache, CHS=155114/16/63, UDMA(100)
> 
> ---snip---
> 
> That seems odd, since they're supposed to be idendtical disks.  This
> isn't really a problem, but I'm curious about why there's a difference.
> 
> Any ideas?
Hello;

I do not know why these are different.  However I can offer an idea
about why they might be different.  You may have noticed how inexpensive
computer hardware is, especially when compared to something else 
of similar complexity.  One of the ways this is accomplished is by 
multi-sourcing parts.  If supplier X isn't able to meet demand, and 
the box is designed with the ability to use another suppliers
parts, the manufacture can switch to supplier Y.  My guess is that 
your drives have slightly different parts in them.  Something you may be 
able to observe if you inspect the drive circuit boards.

The performance of both drives is likely to meet spec.  It is 
possible one, or the other, may exceed spec in some way.

Vince