160 Gb Harddisk: needs extra tweeking?

[Chuck Swiger]

Rob wrote:
> It comes with a tiny CD-rom, about 8cm in diameter, entitled
> "Data Lifeguard Tools". I don't know what to do with this CDrom.

You can probably run the software on it to check the hard drive, "format" it 
(as in, create a MBR and probably FAT and maybe NTFS filesystems), etc.  You 
don't need any of the software on there when using FreeBSD, per se, but the 
manufacturers utilities are generally useful for troubleshooting and diagnostics.

> I am planning to use this harddisk as the only harddisk in
> my PC and install FreeBSD (preferably version 5-Current) on it.
> Will I encounter problems? Does it need extra tweeking?

Hopefully: no, no.

> The Western Digital homepage says somewhere: "Hard drives larger than
> 137 GB require a controller card to utilize full drive capacity."
> What does that mean?

If your motherboard is not new enough to support LBA/48-bit addressing, then 
your motherboard won't properly recognize the size of the drive.  Older 
motherboards which support the previous LBA standard can only see up to 137 GB 
(and drives before that were limited to 8.4 GB using extended C/H/S, and 
before that to 540MB using classic BIOS C/H/S geometries).

The short form of the above is, try the drive out and see what your BIOS 
recognizes it as.

> Another question. The Western Digital homepage lists this about the 
> harddisk:
>   Data Transfer Rate (Buffer to Host)
>     100 MB/s (Mode 5 Ultra ATA)
>     66.6 MB/s (Mode 4 Ultra ATA)
>     33.3 MB/s (Mode 2 Ultra ATA)
>     16.6 MB/s (Mode 4 PIO)
>     16.6 MB/s (Mode 2 multi-word DMA)
> 
> Do I have to tell this to the kernel somehow, or is this a BIOS thing?

This is some of both: your BIOS ought to have settings for enabling and 
controlling the DMA mode used to access the drive.  The kernel will figure 
things out from there, although it does it's own testing to try and recognize 
problems with your cabling or configuration, and may "fall back" to running at 
a slower speed.

See "man atacontrol" for ways of changing the speed while the system is running.

> Are there good reasons not to choose the fastest option "Mode 5" here?

Use the fastest speed you can.  Good reasons not to choose the fastest speed 
might include using a 40-pin ATA-33 cable rather than a newer 80-pin cable, or 
having slower devices like a CD-ROM on the same IDE channel, or if your 
motherboard doesn't support all of the speeds the drive does.

-- 
-Chuck