[wellylug] New HDD on old motherboard

Brent Wood pcreso at pcreso.com
Mon Dec 6 12:02:21 NZDT 2004


--- David Antliff <dave.antliff at paradise.net.nz> wrote:

> Really? My understanding is that Linux doesn't even care what the BIOS 
> says about a disk - it does it's own probing. Hence, with the jumper set 
> to 32GiB and auto-geometry resizing enabled, the BIOS can see the disk, 
> the bootloader can find the kernel, the kernel determines the correct 
> geometry, and then the kernel can find the root filesystem and bring up 
> the system, including DMA drivers. 

In theory, yes. In practice, depending on how the motherboard & BIOS implement
the IDE subsystem it doesn't always work in practice. Linux's IDE probing can
be misinformed by the motherboard &/or HDD &/or HDD controller firmware.

Like a good (eg, not Promise) hardware RAID solution lies to Linux (or any OS)
about what disks are installed. Linux actually doesn't know what disks are
there. Works fine though. In any good hot-swap implementation, the OS shouldn't
know or care that a drive has failed, been replaced or is rebuilding. That is
the role of the controller firmware. 

But generally, you are right, Linux will often work fine even when the BIOS has
problems. But such problems are not always easily rectified by drivers, & Linux
will not always work as you would hope in such cases :-(


Brent




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