Re: 160 Gb Harddisk: needs extra tweeking?

2004-06-15 Thread 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
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Re: 160 Gb Harddisk: needs extra tweeking?

2004-06-15 Thread Bob Johnson
Message: 10
Date: Tue, 15 Jun 2004 22:26:05 +0900
From: Rob [EMAIL PROTECTED]
Subject: 160 Gb Harddisk: needs extra tweeking?
To: [EMAIL PROTECTED]
Message-ID: [EMAIL PROTECTED]

Hi,
I never had such a monster of a big harddisk; hence my question.
I've got a 160 Gb Western Digital Harddisk (WD 1600 JB).
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 should probably ignore the disk.  I do.
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?
I use two in my old Cyrix 133 MHz mailserver and they work fine.  I 
don't recall doing any tweaking, except perhaps adjusting the number of 
inodes when I formatted it.  More about that below.

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?
Good question.  I didn't need to find out, because one of my drives came 
with an Ultra-ATA controller card. Usually if your BIOS can figure out 
how to boot from it and get the FreeBSD kernel loaded, you will be ok.

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?
Are there good reasons not to choose the fastest option Mode 5 here?
The kernel ATA driver will figure it out.  It will use the highest data 
rate your controller and hard drive can both manage, IF you use the 
correct cable.  If you use a standard ATA cable, then your speed will be 
limited (to 33.3 MB/s, I think).  Be sure you use a high speed cable if 
you have a high speed controller.  The default is probably to use PIO, 
so if you want the possibly faster DMA mode, you will need to figure out 
how to do that.  man ad will probably provide more useful information.

When you get to the point where you are formatting the device, think 
about what you are going to be storing on it.  If it will be a bunch of 
very large files, you can format it with fewer inodes, which will make 
more capacity available for data and less for overhead.  On the other 
hand, if you are going to be storing a bunch of small files, you will 
need more inodes.  You use at least one inode per file, and when you run 
out of inodes, you can't have any more files, even if there is still 
space on the disk.  The default installation assumes something like an 
average of 8K bytes/file, so if your files will be much smaller than 
that, you should adjust the format accordingly.

If you are manually adjusting things, you would use something like
  newfs -i 32768 [remaining args]
to reformat your drive assuming 32K bytes per file.  I think you can 
also do this when you are configuring the BSD partitions in sysinstall.



Thanks for help and advice.
Rob.
Hope it helps.
- Bob
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