Normally I just let something like this slide, but frankly, there are so
many errors on your part, I hardly no where to begin. Perhaps you need a
refresher course or something. It's one thing to goof here or there, but
holy cow, where to begin, where to begin.
Anyway, comments below.
Jim
Jim said:
Let's be more precise here w/ the terminology, that's the source of some of
the confusion. We're confining the discussion to Windows/DOS environments
only.
- A (hard) drive has zero or more partitions.
Wrong: A hard drive cannot have zero partitions, zero means nothing, so to say such a thing is a
contradiction of terms.
Wrong - If I buy a new HD, tell us, how many partitions does it contain?
ZERO! In fact, if I run the XP installer, it asks if I want to install in
the "unpartitioned" space! Besides that unpartitioned space, please tell
use what else is there? Nothing, just a lot of empty, unpartitioned space.
If you don't believe this is the case, consider the partition table in the
MBR (Master Boot Record). The partition table points to (addresses) the
existing partitions, correct? If you examine any new HD (or any HD that's
had all its partitions deleted), the partition table contains zeroes in the
address fields of all four possible partition table entries. In fact,
that's the definition of "deleted", the partition table doesn't contain an
address to the partition. But how can this be? If there can't be zero
partitions (according to you), tell us, exactly where does the address to
that mysterious, lone partition reside?
- A partition can be of two types, primary or extended.
Wrong: it is Primary, Extended, Logical.
There's a bit of a semantic issue here. You can define either a primary or
extended partition, those are really the only true types of partitions.
Within an extended partition, you can define volumes, or as some would call
it, "logical partitions". The term "partition" in this context can be
confusing, esp. to a newbie, so I tend to stay away from it. It's qualified
as a "logical" partition because the partition table in the MBR (master boot
record) only has entries for four partitions, and of those, they must either
be a primary or extended partitions. There are no "logical" partitions in
the partition table (if only due to physical limitations, since you can have
many, many logical partitions, or "volumes" within an extended partition).
Instead, the one and only allowed extended partition uses "sub-addressing"
from its own address stored in the partition table to address the individual
volumes (or logical partitions). *That's* why they're called logical, they
have no actual physical presence in the partition table, they are only
suballocations" (logical) with the extended partition. This is also why it
can be problematic to install an OS in the extended partition (can be done
at times, but not officially supported by MS). The DOS bootstrap examines
the partition table and looks for an "active" indicator to determine the
bootable partition. But the extended partition is simply a pointer to a
partition of other volumes (logical partitions), so having the active
indicator specified on the extended partition itself isn't very meaningful,
to which specific volume (logical partition) are you referring?
In the end, its semantics, but it's confusing to refer to extended
partitions as partitions at all (which your reply has so clearly
illustrated). I find it much more edifying to simply refer to primary and
extended partitions (since that's what appears in the partition table), then
explain that the extended partition can contain zero or more volumes (if you
prefer to use the "extended partition" terminology, be my guest, it's the
same thing as a volume). But to say that the HD can have three types of
partitions, well, you say TomAto, I say TOmatO.
This is one case where a simple clarification on your part would have been
warranted, indeed, appreciated. But given your confusion, I suppose this is
not to be expected.
- A (hard) drive can have a maximum of 4 primary partitions, or, 3 primary
partitions and 1 extended partition.
Wrong: If the drive is setup as a RAID, then it can be striped into many
other primary partitions.
RAID? Who in the world brought RAID into this discussion?! You're running
off the rails at this point. RAID is moot, irrelevant. So I'm not even
sure what you're getting at.
If we keep the discussion to simple, hardware-based, two HD RAID0
(striping), the two HDs are logically treated as a single HD. I can
configure that RAID0 with two new, clean (unpartitioned) HDs if I like,
indeed, it's preferred. I configure the RAID BIOS to treat the two
*physical* HDs as one *logical* HD. None of this has anything, nothing,
nada, zippo, to do with partitioning. I partition the RAID0 array *after*
creation of the array. From that point on, the definition of partitions is
EXACTLY the same a single HD, because for all intents and purposes, the
array is seen as a single HD to the BIOS and OS. As a result, the rules I
outlined above remained 100% true.
Again, I don't even know for sure what RAID has to do w/ any of this, RAID
is RAID, partitioning is partitioning. Again, you seem confused. But I
thought a lesson in RAID might be educational too. RAID has NOTHING TO DO
WITH PARTIONING, NOTHING! It's about the relationship of HDs (for hardware
RAID), not partitions.
- An extended partition can contain zero or more volumes.
Still Wrong: zero means zero as applied earlier
Ever use FDISK? Ever create an extended partition? After you create the
extended partition, what do you do next? You define a volume (ok, if you
prefer, logical partition) within that extended partition. In between the
time you create the extended and define your first volume (logical
partition) within it, how many volumes does the extended/logical partition
actually contain? (jeopardy theme) ZERO!
Now, does it make sense to create an extended partition and never define at
least one volume (logical partition)? Of course not, presumably its the
first thing you'll do. But it's a two step process, and technically you
don't *have* to create any volumes (logical partitions) if you don't want
to. But as sure as the sun rises in the East, had I stated that the
extended partition can contain ONE (1) or more volumes (logical partitions),
somebody else would have played "gotcha" and declared, WRONG, it can contain
zero as well. So you can't win in these forums, you get it from both sides.
- You format primary partitions, or, extended volumes, not "drives".
She specified volumes of a "partitioned" hard drive, so you obviously
miss some words.
Yes, and since she was clearly confused about the relationship of volumes to
partitioning (such as yourself), I thought it best to explain the complete
relationship, lest she be more confused, and unconvinced by simple
declarations like "it's OK to format the volume, it won't affect other
volumes". And I'm glad I did, because clearly she isn't the only confused
one in this NG.
Have a nice day, and I sincerely mean it, HTH
Jim
