T
Timothy Daniels
D.T said:
First, what is a logical drive? Or do you mean
"logical disk"?
*TimDaniels*
First, what is a logical drive? Or do you mean
"logical disk"?
*TimDaniels*
G
Guest
A full guide to XP drive management and terminolgy.
Windows XP supports up to four partitions per hard disk.
Windows XP supports two main partition TYPES: Primary and Extended.
A primary partition is one from which one can boot up an Operating System.
All four partitions can be designated as Primary [or bootable, should one
wish to install more than one Operating System, such as XP, 98, Linux etc].
One primary partition at a time must be marked as ‘Active’ designating it as
the one from which the computer will boot: in almost all cases this should be
the ‘C-Drive’.
One partition can be allocated as an Extended Partition. These differ in
that they are not formatted with a file system or assigned a specific drive
letter [‘D’, thru to ‘Z’].
An Extended Partition is then a dedicated area of disk space in which one
can then create a number of Logical Drives.
Logical Drives are similar to primary partitions in that they are
individually formatted with a file system and assigned a drive letter: thus
an extended partition can have an unlimited number of Logical Drives each
with its own drive letter, none of the Logical drives is bootable.
Use for logical drives can be to assign a specific drive letter [logical
drive] for each file type [word document, email, MP3] or on a computer with
many users, one or more logical drive per user.
Windows XP supports three file systems NTFS, FAT32 and FAT [the latter 2
being introduced with earlier Windows systems].
Of the file systems, NTFS is the most versatile and the newest, with a 32
bit address structure which gives it the ability to access the very large
disk drives available now [200Gb drives generally available] and in the
future.
Limitations for each file system are:
FAT – only addresses up to 4Gb of disk space [Windows XP, 95 and earlier
Windows versions only]
FAT32 - only addresses up to 32Gb of disk space [Windows XP, Me 98 and 95
Second Edition]
NTFS - addresses up to 2,000Gb of disk space [Windows XP]
One would use a partitioned hard drive formatted as FAT32 or FAT should one
wish to accommodate a dual boot system [running XP or an earlier Operating
System].
Should one have Windows XP Pro, a further benefit of NTFS is that files can
be encrypted.
Windows XP supports up to four partitions per hard disk.
Windows XP supports two main partition TYPES: Primary and Extended.
A primary partition is one from which one can boot up an Operating System.
All four partitions can be designated as Primary [or bootable, should one
wish to install more than one Operating System, such as XP, 98, Linux etc].
One primary partition at a time must be marked as ‘Active’ designating it as
the one from which the computer will boot: in almost all cases this should be
the ‘C-Drive’.
One partition can be allocated as an Extended Partition. These differ in
that they are not formatted with a file system or assigned a specific drive
letter [‘D’, thru to ‘Z’].
An Extended Partition is then a dedicated area of disk space in which one
can then create a number of Logical Drives.
Logical Drives are similar to primary partitions in that they are
individually formatted with a file system and assigned a drive letter: thus
an extended partition can have an unlimited number of Logical Drives each
with its own drive letter, none of the Logical drives is bootable.
Use for logical drives can be to assign a specific drive letter [logical
drive] for each file type [word document, email, MP3] or on a computer with
many users, one or more logical drive per user.
Windows XP supports three file systems NTFS, FAT32 and FAT [the latter 2
being introduced with earlier Windows systems].
Of the file systems, NTFS is the most versatile and the newest, with a 32
bit address structure which gives it the ability to access the very large
disk drives available now [200Gb drives generally available] and in the
future.
Limitations for each file system are:
FAT – only addresses up to 4Gb of disk space [Windows XP, 95 and earlier
Windows versions only]
FAT32 - only addresses up to 32Gb of disk space [Windows XP, Me 98 and 95
Second Edition]
NTFS - addresses up to 2,000Gb of disk space [Windows XP]
One would use a partitioned hard drive formatted as FAT32 or FAT should one
wish to accommodate a dual boot system [running XP or an earlier Operating
System].
Should one have Windows XP Pro, a further benefit of NTFS is that files can
be encrypted.
W
wooly.bully
Well I guess I broke that rule since I currently have (5) partitions
(F: G: H: I J
on my SATA drive in my Windows XP system. Or does thisonly apply to the first drive?
B
Bob I
Only 4 PRIMARY partitions. I suspect you have 2, a Primary, and an
Extended which has been sliced in to 4 logicals.
Extended which has been sliced in to 4 logicals.
R
R. C. White
Hi, Wooly.Bully.
No. Each sector on a physical drive holds 512 bytes. The first physical
sector on each HDD (SATA or otherwise) holds the MBR (Master Boot Record -
about 400 bytes of code) plus the Partition Table for that HDD. The
partition table is only 64 bytes long: only 16 bytes for each of 4 possible
partitions. There's no room to put a 5th entry in the partition table.
But, if one of those partitions is an "extended partition", the first
physical sector of that extended partition will contain the "Extended
Partition Table". This table can contain entries for multiple "logical
drives" within the extended partition. Each of these logical drives can be
assigned a "drive letter", just like a primary partition. Each can be
formatted (FAT, FAT32 or NTFS) independently of other logical drives or
primary partitions. Each logical drive and each primary partition is a
"volume".
Since a logical drive is assigned a "drive" letter (just like a primary
partition) and formatted (just like a primary partition), it is often
referred to as a "drive" or a "partition". We often say that we "format a
hard drive", but that is not really accurate. First we create one or more
primary partitions and/or logical drives and then we format those volumes,
not the physical drive. As Abe Lincoln is said to have said, "Calling a
tail a leg don't make it a leg; a dog still has only 4 legs, even if you
call a tail a leg."
And your HD doesn't have 5 partitions, even if you call a logical drive a
partition. ;^}
RC
--
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
No. Each sector on a physical drive holds 512 bytes. The first physical
sector on each HDD (SATA or otherwise) holds the MBR (Master Boot Record -
about 400 bytes of code) plus the Partition Table for that HDD. The
partition table is only 64 bytes long: only 16 bytes for each of 4 possible
partitions. There's no room to put a 5th entry in the partition table.
But, if one of those partitions is an "extended partition", the first
physical sector of that extended partition will contain the "Extended
Partition Table". This table can contain entries for multiple "logical
drives" within the extended partition. Each of these logical drives can be
assigned a "drive letter", just like a primary partition. Each can be
formatted (FAT, FAT32 or NTFS) independently of other logical drives or
primary partitions. Each logical drive and each primary partition is a
"volume".
Since a logical drive is assigned a "drive" letter (just like a primary
partition) and formatted (just like a primary partition), it is often
referred to as a "drive" or a "partition". We often say that we "format a
hard drive", but that is not really accurate. First we create one or more
primary partitions and/or logical drives and then we format those volumes,
not the physical drive. As Abe Lincoln is said to have said, "Calling a
tail a leg don't make it a leg; a dog still has only 4 legs, even if you
call a tail a leg."
And your HD doesn't have 5 partitions, even if you call a logical drive a
partition. ;^}
RC
--
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
Well I guess I broke that rule since I currently have (5) partitions
(F: G: H: I J
only apply to the first drive?
W
wooly.bully
You're right. I should read closer. They are logical, but I'm not.
W
Walter Clayton
No. They are two different animals.
T
Timothy Daniels
Thanks for the clarification of logical drives being sections of an
extended partition.
But also keep in mind that an OS can be loaded from a logical
drive. The "active" partition (which must be a Primary partition)
must contain the boot manager and loader, but the boot menu
can "point to" a logical drive (i.e. partition) from which the OS is
to be loaded. So your phrase "from which the computer will boot"
does not necessarily mean "from which the OS will be loaded",
but rather "where the boot manager and loader are to be found".
*TimDaniels*
extended partition.
But also keep in mind that an OS can be loaded from a logical
drive. The "active" partition (which must be a Primary partition)
must contain the boot manager and loader, but the boot menu
can "point to" a logical drive (i.e. partition) from which the OS is
to be loaded. So your phrase "from which the computer will boot"
does not necessarily mean "from which the OS will be loaded",
but rather "where the boot manager and loader are to be found".
*TimDaniels*
BAR said:
G
Guest
Bob I: put on your glasses and read carefully: in my text was ' thus
an extended partition can have an unlimited number of Logical Drives each '.
an extended partition can have an unlimited number of Logical Drives each '.
T
Tom
Timothy Daniels said:
Well BAR has some info incorrect:
BAR said:
FAT (File Allocation table) is just the acromyn for the different size
possibilities using FAT. They are FAT12, FAT16, and FAT32, IOWs, there isn't
a common size called just FAT, and FAT32.
BAR said:
He means FAT16, which can only be installed on volumes up to 2Gs (referenced
below with "limitation" links).
BAR said:
This is somewhat wrong, XP on any one hard drive, can support only four
*primary*
partitions at a time, but if one e.g. had 3 primary, then they can have
more logical drives in an extended partition. But he does
contradict this statement in the rest of his post, with the
extended/logical drive info.
BAR said:
Again, this is wrong, but I am guessing he is stating how XP (as well as
2000), in itself
using its installation utility, only will format, and install on a 32g
FAT32 partition. FAT32 in itself, and handle volumes up to 2000gigs. But XP
can install on a partition larger than 32gigs, if one formats (ala a 98
bootdisk) that partition to a larger size, before using the XP install disk.
As far as real size limits using the OSes mentioned, it would be a 127gig
(binary) max partition.
http://support.microsoft.com/kb/184006
Here are a few references to size limitations using the various file
formats:
Size Limitations in NTFS and FAT File Systems
http://www.microsoft.com/resources/...Windows/XP/all/reskit/en-us/prkc_fil_tdrn.asp
FAT Sizes: FAT12, FAT16 and FAT32
http://www.pcguide.com/ref/hdd/file/partSizes-c.html
This is correct in the context you use, but you left out what BAR stated in
the whole scheme, which was:
This is true, since he said *an* operating system, as you have to have a
Primary drive to do so, which will contain the bootloader. But the
explanation of how it works from there on is true from your point. But I
will address one other thing BAR stated, which again is untrue in its
context
Logical drives are bootable, or else dual-boot scenarios would not be
possible. He just needs to use the context correctly, or else taken as it is
written would negate bootable logical drives. IOWs, if you have a dual-boot
setup (Primary/logical), you can select after the BIOS post, to what OS you
want to boot, hence it is bootable; it simply doesn't contain the
bootloader, which is at the beginning of the Primary partition.
T
Tom
Bob called you correctly as noted from the second line in your previous post
of which you said, "Windows XP supports up to four partitions per hard
disk.", and if you read your previous post further, you even contradict
yourself. Some of your other info is also worng, as I noted to Tim.
of which you said, "Windows XP supports up to four partitions per hard
disk.", and if you read your previous post further, you even contradict
yourself. Some of your other info is also worng, as I noted to Tim.
B
Bob I
I "replied" to wooly.bully and corrected his wrong impression of
"partitions vs. logical drives", PERHAPS YOU should read?
"partitions vs. logical drives", PERHAPS YOU should read?
T
Tom
LOL, this thread is screwed into a cocked hat, I even attributed your reply
to BAR as wooly's LOL. ( I need to stop using google beta groups for
referencing LOL).
But anyway, to be clear on things; Windows (at least from what I know from
95 to now) can have 3 primaries with one extended w/logical drives, or just
simply four primaries, on one hard drive. Some 3rd party partition managers
will allow you create as many primary drives as you please, BootIt NG comes
to mind with this scenario.
to BAR as wooly's LOL. ( I need to stop using google beta groups for
referencing LOL).
But anyway, to be clear on things; Windows (at least from what I know from
95 to now) can have 3 primaries with one extended w/logical drives, or just
simply four primaries, on one hard drive. Some 3rd party partition managers
will allow you create as many primary drives as you please, BootIt NG comes
to mind with this scenario.
R
R. C. White
Hi, Tom - and all.
One big problem in discussing this is the several ambiguous meanings of some
terms, such as "drive", "partition" - and "boot". :>(
As many writers have commented, "We BOOT from the SYSTEM partition and keep
the operating SYSTEM files in the BOOT volume." Microsoft didn't invent
this terminology, but continues to use it.
The boot process must begin in the System Partition, which must be on the
boot device (typically the master HD on the primary IDE controller); this
must be the Active (bootable) partition, which means it must be a Primary
Partition. This partition must have the proper NT-style Boot Sector, and 3
files (NTLDR, NTDETECT.COM and Boot.ini) must be in the Root of that
partition. (In some installations, a few other files, such as NTBOOTDD.SYS,
are required, but these are not typical.)
All the rest of Windows (all recent versions, at least) must be in the Boot
Folder in the Boot Volume. The Boot Folder is named \Windows, by default.
(Except in WinNT and Win2K, where the default is \WinNT; in an upgrade
installation, the new Windows installation inherits the name of the earlier
version, so some WinXP boot folders are named \WinNT.) This Boot Folder -
and its many subfolders - hold the GB or so of WinXP files.
The Boot Volume can be any volume, either a primary partition or a logical
drive, on any HD in the computer. (Maybe it could also be on an external HD
or a rewritable CD/DVD - or even a very large USB flash drive, but I don't
know about that.) The Boot Volume may share the System Partition - and
typically does. There should be a separate Boot Volume for each
installation of Windows; Microsoft (and nearly all other gurus) strongly
advise against putting two Windows installations into a single volume.
Logical drives are not bootable. A dual-boot must start in the System
Partition (which must be a Primary Partition). But C:\Boot.ini will point
to the Boot Folder, which may very well be in a logical drive. (In my own
system, C: is a small FAT-formatted primary partition on my IBM SCSI HD; my
main WinXP is in D:\Windows, an NTFS-formatted logical drive in the extended
partition on that SCSI HD; other Windows installations are in F:, L:, and
X:, all logical drives in extended partitions on my two IDE HDs and all
NTFS. My boot process starts with C:\NTLDR and then branches to
D:\Windows - or wherever.)
A logical drive can be a "Boot Volume" - but you can't boot from it. :>(
RC
--
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
One big problem in discussing this is the several ambiguous meanings of some
terms, such as "drive", "partition" - and "boot". :>(
As many writers have commented, "We BOOT from the SYSTEM partition and keep
the operating SYSTEM files in the BOOT volume." Microsoft didn't invent
this terminology, but continues to use it.
The boot process must begin in the System Partition, which must be on the
boot device (typically the master HD on the primary IDE controller); this
must be the Active (bootable) partition, which means it must be a Primary
Partition. This partition must have the proper NT-style Boot Sector, and 3
files (NTLDR, NTDETECT.COM and Boot.ini) must be in the Root of that
partition. (In some installations, a few other files, such as NTBOOTDD.SYS,
are required, but these are not typical.)
All the rest of Windows (all recent versions, at least) must be in the Boot
Folder in the Boot Volume. The Boot Folder is named \Windows, by default.
(Except in WinNT and Win2K, where the default is \WinNT; in an upgrade
installation, the new Windows installation inherits the name of the earlier
version, so some WinXP boot folders are named \WinNT.) This Boot Folder -
and its many subfolders - hold the GB or so of WinXP files.
The Boot Volume can be any volume, either a primary partition or a logical
drive, on any HD in the computer. (Maybe it could also be on an external HD
or a rewritable CD/DVD - or even a very large USB flash drive, but I don't
know about that.) The Boot Volume may share the System Partition - and
typically does. There should be a separate Boot Volume for each
installation of Windows; Microsoft (and nearly all other gurus) strongly
advise against putting two Windows installations into a single volume.
Logical drives are not bootable. A dual-boot must start in the System
Partition (which must be a Primary Partition). But C:\Boot.ini will point
to the Boot Folder, which may very well be in a logical drive. (In my own
system, C: is a small FAT-formatted primary partition on my IBM SCSI HD; my
main WinXP is in D:\Windows, an NTFS-formatted logical drive in the extended
partition on that SCSI HD; other Windows installations are in F:, L:, and
X:, all logical drives in extended partitions on my two IDE HDs and all
NTFS. My boot process starts with C:\NTLDR and then branches to
D:\Windows - or wherever.)
A logical drive can be a "Boot Volume" - but you can't boot from it. :>(
RC
--
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
Tom said:
T
Tom
I guees semantics here is what is the issue, anyway, here goes:
Right, I stated that regarding Primary partitions in my post to Tim.
<snipped)
Read what I said, to get into a logical drive, you need to boot into it, as
I pointed out in post BIOS load. All I said was from actually "booting", if
a partition cannot be booted into, then it isn't bootable. I simply mean
literally, that when one chooses a dual-boot, they choose to which one they
want to boot into, hence, it is bootable from that standpoint. Regardless of
what you boot into, the Post BIOS choice is there to make the boot.
I said this regarding the Primary drive in my post to Tim
And I never said one could. refer to my post BIOS comments in this
reply, and the one before.
R. C. White said:
Right, I stated that regarding Primary partitions in my post to Tim.
<snipped)
Read what I said, to get into a logical drive, you need to boot into it, as
I pointed out in post BIOS load. All I said was from actually "booting", if
a partition cannot be booted into, then it isn't bootable. I simply mean
literally, that when one chooses a dual-boot, they choose to which one they
want to boot into, hence, it is bootable from that standpoint. Regardless of
what you boot into, the Post BIOS choice is there to make the boot.
I said this regarding the Primary drive in my post to Tim
And I never said one could
. refer to my post BIOS comments in thisreply, and the one before.
R
R. C. White
Hi, Tom.
Agreed! I just replied to another message from you in another subthread.
;^}
It's not just Windows. It's even more fundamental than that. It's all
MBR-type HDs, whether they run MS-DOS or Linux or who-knows-what.
In another subthread you pointed to a page in the WinXP Pro Resource Kit.
As you probably know, that entire RK is available online, and it contains a
wealth of information. One of my favorite parts is Chapter 27,
Troubleshooting Disks and File Systems. It's kind of hard to navigate
around in the online RK, and URLs I post here usually get into the RK but
not to the page I had in mind. :>( But if you get to the top URL:
http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/
You can navigate from there to:
Welcome > Part VI System Troubleshooting > Ch 27 Troubleshooting Disks and
File Systems > Disk Sectors Critical to Startup > Disk Sectors on MBR
Disks
and then to Master Boot Record on Basic Disks. There you will find a
picture of the partition table, showing that it consists of only 64 bytes,
allowing for only four 16-byte entries for only four partitions. To change
this would take reprogramming the whole disk structure. Following the table
is a byte-by-byte explanation of what each code in the table means,
including the code for which (if any) is the one Active partition and which
(if any) is the one Extended partition.
These Resource Kits are truly valuable resources! I've read (most of) each
version since Win98. They are big books (1700+ pages in the WinXP second
edition). About half of each book does not interest me much at all; I'm not
concerned with deploying Windows to thousands of desktops in offices and
remote locations around the world. But the other half justifies the entire
purchase price (US$70 or so) of the entire book IF I spend - INVEST! - the
time to study the chapters on disks, file systems, the setup and startup
processes, etc. I figure the time I invest in studying these topics will
benefit me, not just in solving today's problem but for as long as I
continue to use Windows and computers - which probably will be the rest of
my life. I can merge this information with my own experience and with what
"I've heard" in newsgroups, from experts and from others. And if I can read
the whole book online for free, too, so much the better!
RC
Agreed! I just replied to another message from you in another subthread.
;^}
It's not just Windows. It's even more fundamental than that. It's all
MBR-type HDs, whether they run MS-DOS or Linux or who-knows-what.
In another subthread you pointed to a page in the WinXP Pro Resource Kit.
As you probably know, that entire RK is available online, and it contains a
wealth of information. One of my favorite parts is Chapter 27,
Troubleshooting Disks and File Systems. It's kind of hard to navigate
around in the online RK, and URLs I post here usually get into the RK but
not to the page I had in mind. :>( But if you get to the top URL:
http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/
You can navigate from there to:
Welcome > Part VI System Troubleshooting > Ch 27 Troubleshooting Disks and
File Systems > Disk Sectors Critical to Startup > Disk Sectors on MBR
Disks
and then to Master Boot Record on Basic Disks. There you will find a
picture of the partition table, showing that it consists of only 64 bytes,
allowing for only four 16-byte entries for only four partitions. To change
this would take reprogramming the whole disk structure. Following the table
is a byte-by-byte explanation of what each code in the table means,
including the code for which (if any) is the one Active partition and which
(if any) is the one Extended partition.
These Resource Kits are truly valuable resources! I've read (most of) each
version since Win98. They are big books (1700+ pages in the WinXP second
edition). About half of each book does not interest me much at all; I'm not
concerned with deploying Windows to thousands of desktops in offices and
remote locations around the world. But the other half justifies the entire
purchase price (US$70 or so) of the entire book IF I spend - INVEST! - the
time to study the chapters on disks, file systems, the setup and startup
processes, etc. I figure the time I invest in studying these topics will
benefit me, not just in solving today's problem but for as long as I
continue to use Windows and computers - which probably will be the rest of
my life. I can merge this information with my own experience and with what
"I've heard" in newsgroups, from experts and from others. And if I can read
the whole book online for free, too, so much the better!
RC
T
Tom
I particularly don't get into the files structures and formats for HDDs,
though I am familiar with Windows and Linux products. I only made my comment
on what can be made on a HDD using the versions of Windows I know. I also
pointed out in another thread (since you mention the MBR table -16byte per
partition x 4 partitions limit = 64bytes here) that one can make more than 4
primary partitions using a 3rd party partition manager.
Anyway, thanks for the info.
though I am familiar with Windows and Linux products. I only made my comment
on what can be made on a HDD using the versions of Windows I know. I also
pointed out in another thread (since you mention the MBR table -16byte per
partition x 4 partitions limit = 64bytes here) that one can make more than 4
primary partitions using a 3rd party partition manager.
Anyway, thanks for the info.
C
cquirke (MVP Windows shell/user)
On Thu, 24 Mar 2005 04:05:03 -0800, BAR
FATxx includes FAT12, FAT16 and FAT32, though it's unlikely you'd have
any HD volumes small enough to use FAT12. FWIW, I use the term
"volume" to refer to both primary partitions and logical volumes
within an extended partition. AFAIK there may be mutiple primary
partitions, but no more than one extended partition per HD.
Detail:
- NT can support 4G FAT16 volumes with 64k clusters
- Win95SR2 thru WinME support only up to 2G FAT16 with 32k clusters
False.
FAT32 supports HDs and volumes well over 32G, even beyond 137G, but
not all FAT32-capable OSs support HDs over 137G (such support starts
from XP SP1, AFAIK). All OSs that support FAT32, support FAT32 > 32G.
It's just that XP's volume formatter is not only too lame to format
FAT32 volumes over 32G, but is even too lame to realize its
limitations and avoid rtying. Instead, it starts to format the volume
(losing any data that was there), and grinds along until it hits 32G,
then it falls over because the volume is "too big".
This is not a FAT32 issue; it is an XP quality failure problem.
AFAIK 2TB is the max limit for FAT32 as well.
Very much a two-edged sword, that, given casual use of EFS without a
full understanding and management of the implications is likely to end
up in tears, if the encryption key info is lost.
On FATxx vs. NTFS, http://cquirke.mvps.org/ntfs.htm refers.
To disable the 'Tip of the Day' feature...
FATxx includes FAT12, FAT16 and FAT32, though it's unlikely you'd have
any HD volumes small enough to use FAT12. FWIW, I use the term
"volume" to refer to both primary partitions and logical volumes
within an extended partition. AFAIK there may be mutiple primary
partitions, but no more than one extended partition per HD.
Detail:
- NT can support 4G FAT16 volumes with 64k clusters
- Win95SR2 thru WinME support only up to 2G FAT16 with 32k clusters
False.
FAT32 supports HDs and volumes well over 32G, even beyond 137G, but
not all FAT32-capable OSs support HDs over 137G (such support starts
from XP SP1, AFAIK). All OSs that support FAT32, support FAT32 > 32G.
It's just that XP's volume formatter is not only too lame to format
FAT32 volumes over 32G, but is even too lame to realize its
limitations and avoid rtying. Instead, it starts to format the volume
(losing any data that was there), and grinds along until it hits 32G,
then it falls over because the volume is "too big".
This is not a FAT32 issue; it is an XP quality failure problem.
AFAIK 2TB is the max limit for FAT32 as well.
Very much a two-edged sword, that, given casual use of EFS without a
full understanding and management of the implications is likely to end
up in tears, if the encryption key info is lost.
On FATxx vs. NTFS, http://cquirke.mvps.org/ntfs.htm refers.
Tip Of The Day:
To disable the 'Tip of the Day' feature...
C
cquirke (MVP Windows shell/user)
Well I guess I broke that rule since I currently have (5) partitions
(F: G: H: I J
only apply to the first drive?
It's not a Windows thing, it is a system thing.
The system defines the structure of the partition table, one of which
is held in each physical HD. It is this that limits you to 4
partitions per physical HD.
Windows is an OS, and OSs are "guests" of the system. Each OS resides
in one or more partitions. Each partition has a type byte that OSs
can refer to to recognise partitions and file systems they can use.
If they don't recognise the partition type, they are to ignore that
partition, and should never write any information to it.
There are two ways to break this limit:
1) Extend the system's partitioning scheme
This is what some system-level boot managers, such as BING, do. They
extend the standard partition table to hold more partitions, storing
this additional information elsewhere in the HD.
For this to work, the boot manager's "special" code has to run at
boot, as it will if that HD's Master Boot Record (MBR) code is booted
up. But if this code is replaced by standard system MBR code (e.g.
FDisk /MBR, Recovery Console FixMBR, some av's boot cleanup) or if a
different device is booted so the MBR code is bypassed, then it all
falls apart; only the "real" partition table is seen.
2) Use an extended partition to hold more (logical) volumes
MS OSs use the "extended" partition type as a container for multiple
volumes, each of which with its own file system and drive letter.
This is most likely how your system appears to break the 4-partition
rule. Lately, several other OSs such as Linux also recognise extended
partition and can use the space inside to hold their own logical
volumes. When these use file systems unknown to MS, problems may
arise when MS tools are used to manage the extended partition.
For example, when I installed Linux, I was surprised to see it
locating its three volumes within the existing extended partition,
instead of the free space outside all existing partitions that I'd set
aside for it. In fact, it resized the extended partition to fill that
free space, and then used this new space within the extended partition
for its own hard drive volumes.
The most accurate diagnostic instrument
in medicine is the Retrospectoscope
T
Tom
cquirke (MVP Windows shell/user) said:
While that may be your opinion of lameness, using a partition size on FAT32
on anything bigger that 16gs, is a waste anyway IMHO, besides the facts of
the file size limits FAT32 has. In todays larger drives that are available,
it is a waste to use it. I consider that function made purposefully for the
sole reason of wasting space and performance.
Correct for both filing systems, for drive support that is, but:
The maximum possible number of clusters on a volume using the FAT32 file
system is 268,435,445. With a maximum of 32 KB per cluster with space for
the file allocation table (FAT), this equates to a maximum disk size of
approximately 8 terabytes (TB).
NTFS can be 16 exabytes.
<snipped>