DeltaX and Hard Drives

[greengoose1]

Hi All, I changed the title a bit so it would be better to Search for later on. I added a X right after Delta in the thread we just finished. I will also tie the threads together to make it easier as we did before.

Ok then, all of the readers (that's you) have the first thread locked down. (Right?) Where you all have a most wonderful Maintenence, Back UP, and Security plan and procedure in place, right?
I sure hope so.

Now for hard drives. They have gotten bigger and faster since the last time we addressed this subject. And this time we are going from A to Z with hard drives so you will know what they look like inside and out, how they operate (Did you know the speed of the platter drags air with it and that is what keeps the head above the platter in operation.), how they are setup and interfaced to the software controls (What's a cylinder?), and finally how the data gets in and out of one of these here critters ( what is the boot mbr or a cluster?). And maybe we'll get into Partition Magic and other third party utility programs. And with the talent hanging in the wings, there is no reason each and everyone of us won't learn something.

Ok, let's get going. A hard drive is a storage device where you can put your data into and retrieve it some how. So the first question then is - Can you explain the physical hard drive and what is in it? These little dodads in this thing is what has got to be interfaced electronically to your software. Have at it and have fun.

The "DeltaX" and Stuff (Maintenence & Backups) thread can be found here

[SuperSparks]

OK, off we go then! Let's start with the mechanics of the thing. First of all we have the platters - these are just what they sound like, flat disks made of glass or aluminium and coated with a magnetic material. There are several in a drive (how many depends on the capacity of the drive) and they are arranged one above the other about a common drive spindle with a gap between each one to allow the heads to move back and forth. There are 3 common speeds for desktop 3½" drives - 5400RPM (revolutions per minute), 7200RPM and 10,000RPM (this is only available on SCSI drives and the new SATA drives that are coming out, we'll discuss what that means later).

The spindle floats on very high precision bearings and is driven by a high-quality servo motor. Hard drives are manufactured in ultra-clean conditions, and have a very fine air filter on them, as any speck of dust (or even a particle of cigarette smoke for all you horrible smokers) can have disastrous consequences.

Now to talk about heads, I need to look something up first, or someone else can describe them.

[cryos6]

Try this link. Got simple explanation of how harddrives works.

How Harddisk Works

[Train]

Ok, now we are ready to run out and buy one. Are there any possible limitations to how big of one I can use?

[Nix]

Originally posted by Train
Ok, now we are ready to run out and buy one. Are there any possible limitations to how big of one I can use?

Good question.

This will open up the discussion on the use of overlay programs, UATA and SATA cards and SCSI drives and tie in the limitations of certain older BIOS' to recognise 'large' drives.

Of which I have almost zero knowledge, so I'll leave it to the xeperts.

[Train]

How about Bios limitations with this for a start:

The BIOS limitation or BIOS capacity barrier is the computer’s inability to recognize hard drive capacities larger than allowed by the hard-coded programming contained in your system BIOS. For example, your system BIOS might only be capable of understanding a hard drive capacity of up to 32 GB. If you then attempt to install and auto-detect a 40 GB hard drive, the system will freeze because the BIOS is not capable of understanding the capacity reported by the hard drive. In short, that particular BIOS cannot count past 32 GB.

Systems with BIOS dated prior to July 1994(504 MB Limitation).
Typically these BIOS will have a 504 megabyte (1,024 cylinder) limitation. Prior to this date, most manufacturers' BIOS did not provide the Logical Block Address (LBA) feature needed for proper translation. Some BIOS had LBA mode in the setup, but the feature did not work properly

Systems with BIOS dated after July of 1994 (2.048 GB Limitation).

4.2 GB Limitation

8.4 GB limitation

32 GB limitation.
This condition is caused by the Award BIOS inability to address hard drives greater than 32GB. Award has been made aware of this issue and has fixed their "core" BIOS as of 6/99


64 GB Limitation
There is no 64GB BIOS Capacity Barrier. If you use FDISK to format a drive that is larger than 64 GB, FDISK will report the incorrect disk size.

Then there is the fact that most system BIOSes are limited to 137 GB because it can only support 28 bit Logical Block Addressing (LBA).

Now how would one support a larger monster?

[kallikru]

One way to support larger drives would be to upgrade the bios if the manufacturer had come up with some new bios that would support these drives...this is the preferred way if you ask me. Alternately you could get yourself a PCI controller card that would support your larger drive....or you could use an "overlay" program that will do the same job.

Whatever the method, the mainboard/controller manufacturers must constantly keep up with this rapid expansion of the drive's capacity in expanding the support for their controllers.

[Ridgerunr]

This goes back a' couple years,but for those who want to dig a bit deeper into what Train and others have presented. Have a read here: http://www.spcug.org/reviews/bl0107.htm

[greengoose1]

Good Morning All,

And here is a small excerpt from one of my files that may help to understand drive overlays. Drive overlays - programs designed to overcome BIOS limitations. These program have different names, for example: EZ-Drive (Western Digital), Disk Manager (Seagate), MaxBlast (Maxtor). They are usually supplied with retail-packaged HDDs, and are also available from HDD manufacturers' websites.
When a drive overlay program runs during the boot sequence, it installs a small program that replaces some of the BIOS's drive access services with its own routines. Therefore, in order to access the drive, you must boot from the drive where the drive overlay was installed. If you boot from another drive (diskette, CDROM, another HD), chances are you won't see the "overlayed" drive's partitions.

To uninstall a drive overlay program, you should use it's uninstall feature. The more "low-level" way of doing this - and losing all the files on the drive - is booting from another drive, and typing "FDISK /MBR". At this point, the drive overlay will be overwritten, and looking in FDISK, you'll see "non-DOS" partitions instead of your formerly overlay-driven partitions. You can simply delete them, and create new, overlay-free partitions.
Since the MBR can only have 1 program, it's very likely that an attempt to install 2 different ones (say, installing Linux on a drive with an overlay) will not work, invalidating all drives that depend on the first program.

I think this can explain why people may have problems trying different things when installing. The important starting points for understanding "drive overlays" are included. Also answered is the reason for a data floppy to come with a large GB HDD.

[bistro]

And there's the problem....oftentimes folks go out and buy a new hard drive, see this funny-looking floppy disk with it and then automatically assume they need to install the overlay program in order to complete installation of the drive. Nutso....er......not so. That floppy disk is for "legacy" motherboards/BIOS' only; the old stuff that can't recognize the large hard drive capacities. If your system is fairly new (a few years), then you shouldn't need the overlay program. Put that floppy disk in a drawer and ignore it. Use it for pellet-gun practice or whatever. No...not really--some of them come with hard drive diagnostic utilities that come in handy....once in a blue moon. So keep the little bugger somewhere out of the way.
Not sure on others, but the Western Digital SATA drives come with a SATA controller card and a floppy with SATA drivers on it. That's all fine and good, but if you are installing the drive on a SATA-capable board, then DO NOT use that floppy---it is for that card only (for use with non-SATA mobos) (This came up at another forum...screwed up his computer).

[greengoose1]

We are talking about hard drives and how to use them with a slant on multibooting them. Here's something to think about. Can we use FAT 16 (for older operating systems) along with Fat 32, and NTFS file systems on the same hard drive. Brings up another question - How many operating sytems can go on a drive. Do the individual drives have to be a certain size or can they be uniform for the minimum wasted space?

As you can see you have to know what the hard drives can and can't do.

[Ridgerunr]

This goes to the extreme(to say the least ), but multibooting 'can' go a very long way into never-never land.

http://www.techtv.com/screensavers/p...399433,00.html

[SuperSparks]

Yes we can use FAT16, FAT32, and NTFS on the same drive. The caveat here is that an OS installed on a FAT16 partition can't see a FAT32 or NTFS partition. An OS installed on FAT32 can't see NTFS. An OS installed on NTFS (NT/2000/XP) can see any partition using any of the Microsoft file systems (FAT or NTFS).

Now with the FAT file systems the cluster size is dependant on the partition size:

Default Cluster Sizes for FAT & NTFS

The larger the cluster size, the greater the potential for wasted space - ie if the cluster size is 32KB and you save a file containing "Hello World" in Notepad (11 bytes), it will take an entire 32KB cluster.

NTFS has a default cluster size of 4KB regardless of the partition size, though it's possible to force a format to use a different cluster size if desired. Also very small files like my "Hello world" example are stored directly in the Master File Table itself, rather than wasting a cluster on it.

[greengoose1]

And Partition Magic can really really help when you are working with your Hard drives. I think Fdisk and Format has its place as in setting up a hard drive initially but after that you can save alot of time by using Partition Magic or anything similar for changing partitions and tweaking a hard drive. (remember - before you start anything like this always always make a current backup).

[SuperSparks]

Yes I agree, PM is a very nice tool. It is rather expensive for the average user though, as it will be used very infrequently. And I've had to upgrade 3 times over as many years because of changedsto the file systems which it couldn't cope with (ie the very minor change from NTFS 5 (Win2000) to NTFS 5.1 (WinXP)). For those on a budget and who don't mind the rather unfriendly UI, here is a good freeware partition manager:

Ranish Partition Manager

And anyone who isn't going to change their partitioning after the initial setup of the drive can use Fdisk or the built-in Win2000/XP partitioning tools, availble directly from Setup or from the Recovery Console:

How to Use Fdisk and Format

Description of the Windows 2000 Recovery Console

Description of the XP Recovery Console