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The boot process: a step by step approach to booting.


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#76 LeMOGO

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Posted 13 February 2011 - 12:54 PM

My problem is, I did not refuse!
...and am still being accused of doing so ;).
hmmmm!

#77 Wonko the Sane

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Posted 13 February 2011 - 01:03 PM

My problem is, I did not refuse!
...and am still being accused of doing so ;).
hmmmm!


Yep :heh:, and my consideration was that even if you refused you had the right NOT to be accused of discouraging anyone or have your attitude criticized.

#13 3.2 :)

;)
Wonko

#78 LeMOGO

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Posted 13 February 2011 - 10:25 PM

Yep :heh:, and my consideration was that even if you refused you had the right NOT to be accused of discouraging anyone or have your attitude criticized.

Well, I would correct it *if* it was true. But I don't see what else to do to satisfy him. Satisfying wonko was a lot easier. I'm glad to see that his opinion is not universal :)

I'm still open minded though! But I deal with facts, not magic, even with self proclaimed "janitors". WAIT! I just see something. Maybe he means he is the one who "cleans" everything up. Ooooh! Now I understand.
Wait! I still don't understand. ;)
hmmmm!
Well, I give up.
Not everybody likes onions.
You know what everybody likes? Parfaits!
Wait! There are no parfaits here. Hmmm!
Well, I guess we'll have to deal with verifiable facts.


--------------------------------------------------------------------------------------------

#13 3.2


Could you please post a link? I'm lost on this one. Better yet, cut and paste.

Thank you.

#79 LeMOGO

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Posted 14 February 2011 - 05:31 AM

Question:

Why do people call logical partitions extended?

I keep reading that, and it makes no sense to me.
My understanding has always been as follows:


  • An extended partition, wich is a primary partition, is created in a master partition table (in the MBR)
  • The entry in the MBR points to the start of the extended partition.
  • At the beginning of the extended partition, there is a partition table sector.
  • That partition table sector has a pointer to the first LOGICAL partition which can be located anywhere within the boundaries of the extended partition.
  • The logical partition itself has a partition sector that defines its boundaries (among other things)

Conclusion: the logical partitioning of thinking should separate them. An extended partition is not a logical partition (they are not defined in the same place) even if it is possible for their boundaries to be the exact same.
Then again, I'm so used to dealing with windows ...
maybe other OSes can nest extended partitions instead of logical ones.

Am I the one missing something here? (janitors input also accepted)
Please correct me where I am wrong.

#80 Wonko the Sane

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Posted 14 February 2011 - 09:13 AM

There is a lot of confusion in the terminology.
Primary partition=Drive=Volume
Extended partition=NOTHING BUT "Extended partition"
Logical Volume inside Extended=Volume
Drive=Volume=filesystem=anything which first sector is a PBR or bootsector <- this is what gets a drive letter or \\.\LogicalDrive
Disk= the outer container of all <- this is what you see in Disk Management or \\.\PhysicalDrive

The most "correct" one conceptually is:
  • Disk=Outer container of EVERYTHING
  • Primary partition=Primary Volume
  • Extended partition=Container of one or more logical volume(s)
  • Logical partition (WRONG)= Logical Volume inside extended

Using the known numbering system, we have:
1. Disk
1.1 Partition (Primary)
1.2 Partition (Primary)
1.3 Partition (Primary)
1.4 Partition (Extended)
1.4.1 Logical volume
1.4.2 Logical volume
1.4.n Logical volume

The above is only an example, the Extended partition can be in any of the 4 available entries.

Slight textual corrections (in order to better narrow the point)

An extended partition, wich is a primary partition, is created in a master partition table (in the MBR)

A pointer to a given area on the disk is written in the form of a partition table entry in the same manner BOTH for a Primary partition and for an Extended one. The limit is a total number of 4 (four) partition table entries, of which theoretically only 1 (one) can be an Extended partition.

The entry in the MBR points to the start of the extended partition.

Any entry in the partition table of the MBR points to the start of the corresponding partition.

In the case of a Primary partition the start (first sector) is a PBR (partition boot record) or bootsector.

At the beginning of the extended partition, there is a partition table sector.

In the case of an Extended Partition the start (first sector) is a EPBR (extended partition boot record).
This sector has a partition table just like the MBR. Some Authors call this EMBR (Extended Master Boot Record).

That partition table sector has a pointer to the first LOGICAL partition which can be located anywhere within the boundaries of the extended partition.

The first entry in this partition table is a pointer to the start of first logical volume which can be located anywhere within the boundaries of the Extended partition; the first sector of the logical volume is a PBR or bootsector, exactly like the bootsector of a Primary partition.

The logical partition itself has a partition sector that defines its boundaries (among other things)

If there is more than one Logical volume in the Extended partition, the second entry in the partition table of the EPBR is a pointer to ANOTHER EPBR, which has:
  • in first partition table entry a pointer to the start of the mth logical volume which can be located anywhere within the boundaries of the Extended partition the first sector of the logical volume is a PBR or bootsector, exactly like the bootsector of a Primary partition.
  • if there is a nth logical volume, than second entry in this mth EPBR is a pointer to the nth EPBR

At the light of the above the numbering could be:
1 Disk
1.1 MBR
1.1.1 First entry in partition table
1.1.1.1 PBR of primary partition
1.1.1.1.1 Primary partition or Primary volume
1.1.2 Second entry in partition table
1.1.2.1 PBR of primary partition
1.1.2.1.1 Primary partition or Primary volume
1.1.3 Third entry in partition table
1.1.3.1 PBR of primary partition
1.1.3.1.1 Primary partition or Primary volume
1.1.4 Fourth entry in partition table
1.1.4.1 EPBR of Extended partition
1.1.4.1.1 PBR of logical volume (first)
1.1.4.1.1.1 Logical volume (first)
1.1.4.1.2 EPBR of logical volume (non first)
1.1.4.1.2.1 PBR of logical volume (non first)
1.1.4.1.2.1.1 Logical volume (non first)
1.1.4.1.2.2 EPBR of logical volume (next non first)
1.1.4.1.2.2.1 PBR of logical volume (next non first)
1.1.4.1.2.2.1.1 Logical volume (next non first)
1.1.4.1.2.2.2 EPBR of logical volume (next non first)
....

In other words the first volume inside extended is "one level below" any primary partition, and any non first volume inside extended is one "level below" the previous logical volume.

Whilst the MBR is a "central node" holding ALL needed info about Primary partitions (or Primary Volumes), when it comes to Logical Volumes inside the Extended partition the info is distributed in a "chain" of EPBR's.


Hope this helps in make things a little more clear.

:cheers:
Wonko

#81 LeMOGO

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Posted 14 February 2011 - 03:46 PM

I like the definitions, but your post is kind of drowning the only one thing I am concerned with: the term "extended partition".

Volume by definition is a file system formatted group of sectors managed as a single unit (partition).
So, I see it as:
Volume = File system = Drive in M$ (mount point)
Partition = container for a volume (type to be chosen)
Partition type: Primary or Extended (secondary / primary extended)
A volume can be superimposed on a partition of type primary, not secondary.

Secondary partition (primary extended) is only a container for other subdivisions.
Each subdivision can be superimposed with a volume (in the same way as the primary partition).

I'm used to looking at the subdivisions in the extended partition as partitions, but not "extended", because they are not.
You are saying that

The most "correct" one conceptually is:

  • ...
  • Logical partition (WRONG) ...


My question is, are they partitions or not?

  • They are defined in partition tables
  • They have the same definitions as a primary partitions
  • They group sectors for assignment to a file system


Assuming your answer is yes (as it should be), and the partition type is *not* extended, they should not be called "extended partitions". But again, I'm not the king of the hill.
However, we need to agree on terminology.
These subdivisions are

  • partitions
  • not extended partitions
  • inside extended partitions
  • a logical subdivision within a given boundary (that of the extended partition)
  • a physical grouping of contiguous sectors (partition of the drive)


It seems to me that the "proper" terminology should be: "logical partition", or "inner extended partition" (as in partition inside an extended partition), and never "extended partition".

Since people tend to mix them, it is good to know that

There is a lot of confusion in the terminology.

so that everyone realizes that, the responsibility to understand rests on the reader. It is necessary to be able to distinguish them in order to know precisely what any author is actually referring to. The only thing that can help, is a clear knowledge of the characteristics of each item.


Does anything that work like this:

maybe other OSes can nest extended partitions instead of logical ones.

Since I do not know all the OSes, I need to ask the question.
*If* any OS can create a and use a partition of type extended (M$ - i.e. type 05 ...) inside the primary partition of type extended (M$ - i.e. type 05 ...), then there can be extended partitions in the primary (MBR) partition table and extended partitions in the extended partition boot record's partition tables,
in which case, we have to realize that some of them might be referring to a partition of type extended that is located in a partition of type extended.

Is any OS known to work like that?
Can they use a type 5 in a type 5?

--------------------------------------------------------------------------------
There is a partition branch at C.3.4.8.1, and a sister MBR branch at B.2.1.2.2. Both very detailed. I also created a table (a picture is worth a 1000 words) to use when making partitioning decisions (I am currently trying to complete it and line up the different sections of RMPrepUSB to sections of the table, so people know where they are writing when making the choices on the interface.

#82 LeMOGO

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Posted 14 February 2011 - 04:44 PM

The logical partition itself has a partition sector that defines its boundaries (among other things)

If there is more than one Logical volume in the Extended partition, the second entry in the partition table of the EPBR is a pointer to ANOTHER EPBR, which has:
  • in first partition table entry a pointer to the start of the mth logical volume which can be located anywhere within the boundaries of the Extended partition the first sector of the logical volume is a PBR or bootsector, exactly like the bootsector of a Primary partition.
  • if there is a nth logical volume, than second entry in this mth EPBR is a pointer to the nth EPBR


I don't see why this is stricken.

  • the EPBR is a "partition table sector" (old terminology): it contains a partition table (and is therefore at the beginning of the partition)
  • the boundaries of the partition that the EPBR belongs to is defined in the partition table that is on the EPBR itself (in the first entry)


Please read previous post also.

#83 Wonko the Sane

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Posted 14 February 2011 - 04:50 PM

Yep, your approach is as good as any else, but is unlike the historical happenings, possibly I am not clear enough, AND it is a COMPLEX topic AND there is a lot of mixed terms.

It is mostly a semantical issue, but once upon the time Extended partitions did not exist.

Historically and in normally (correctly) used terminology, a hard disk could be divided (or parted) in no more than 4 parts (partitions).

Hence anything directly addressed in one of the four entries in partition table of the MBR is a partition, everything else is not.

Using the term "logical partition", would further confuse the ideas with logical volumes that still is not grasped fully by many, if you want to call the container for each logical volume inside the extended partition "secondary partition" or "sub-partition", it may be OK :smiling9: , but AFAIK it would be a neologism.

As I tried to show with the WBS numbering, the problem is UNLIKE logical volumes inside Primary Partitions, the Extended partition , the first Logical volume in it and the "sub-partitions" and the logical volumes inside them are on "different levels" or a lot like a Matryoshka:
http://en.wikipedia....Matryoshka_doll

And the other problem is that first logical Volume inside extended partition behaves differently from all the other ones as it has as "parent" NOT a "sub-partition" but the "extended partition itself".

Originally the whole Extended partition business was one of the demented effects of poor planning, if you see things now, and rationally, the good MS guys have always had 31 out of 32 or 62 out of 63 hidden sectors UNUSED, where they could stack, at the minimum, and including a magic bytes signature and a 14 byte sector header:
31*(512-16)/16=961 partitions by simply extending the primary partition table in the MBR over following sectors, and have DIRECT addressing of all of them (or if you prefer have up to 965 Primary partitions and avoid the need for the "chain" of EPBR's.

Another attempt:
Primary partition=Volume
Extended partition=Container for first logical volume and for any number of sub-partitions
sub-partition= Container for any logical volume inside extended partition BUT the first one
Logical Volume=Volume

Or, if you prefer:
the "parent" of a primary partition is the MBR
the "parent" of a logical volume inside a primary partition is the MBR (as logical volume inside primary=primary partition)
the "parent" of an Extended partiton is the MBR
the "parent" of first sub-partition inside extended is the 1st EPBR
the "parent" of the logical volume inside first partition is the 1st EPBR
the "parent" of sub-partition n is mth (or n-1th) EPBR
the "parent" of the logical volume n is the nth EPBR

The stricken part was just to highlight the confusion, there is no such thing (in commonly used terminology) as a "logical partition" and "partition sector", the first sector of *something* either contains a partition table (and it is a MBR or an EPBR) or contains filesystem info (and it's a volume - or better logical volume first sector or bootsector or PBR)

I have NO idea if any OS can have nested extended partitions, but it is at the same time possible theoretically and - as I see it - extremely dangerous (in the sense of VERY non-standard). :cheers:
It's already difficult enough to manage the current chain of EPBR's that adding a Matryoshka inside a Matryoshka could create ANY kind of problem.

:P
Wonko

#84 LeMOGO

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Posted 14 February 2011 - 05:09 PM

...
It is mostly a semantical issue
...
Using the term "logical partition", would further confuse the ideas with logical volumes that still is not grasped fully by many, if you want to call the container for each logical volume inside the extended partition "secondary partition" or "sub-partition", it may be OK :smiling9: , but AFAIK it would be a neologism.


We have to have a "standard" nomenclature, and I would prefer if it is accurate.
I agree on "secondary partition" because it is a partition, and it is *not* a primary partition. So, that works fine, and avoids any possible misunderstandings.
I am voiding the term "logical" because I am referring to the partition itself, before any file system is applied to it, or after a file system is removed from it (or broken).
"sub-partition" could work also, but since the MBR only contains "primary" partitions, I prefer the former.

I will clean up the map accordingly.

Thank you.

#85 Wonko the Sane

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Posted 14 February 2011 - 05:26 PM

I agree on "secondary partition" because it is a partition, and it is *not* a primary partition. So, that works fine, and avoids any possible misunderstandings.

It's "your" map and "your" vocabulary :cheers:, but as I see it primary and secondary can be mistakenly taken as being on the same level, particularly secondary can be mistaken for extended, whilst "sub-partition" IMHO better conveys the idea of being "at a lower level".

"We" do know:
  • that there can only be TWO types of partitions at "first level" (the MBR): Primary and Extended
  • that the Extended partition is actually a container for one (or more) "secondary partitions"

i.e. in "our" view (because we already know where our towel is :P) the two things that can be written in the MBR are the extents of EITHER a "primary partition" OR an "extended partition".

I fear that less experienced peeps may think that in the MBR you can write the addresses of EITHER a "primary" or a "secondary" partition. :cheers: (being both a kind or type of "partition" whilst the very name of "sub-partition" makes easier to understand that it is NOT a "partition" with the "same dignity" as a "primary partition" or as an "Extended partition"). :smiling9:

:rofl:
Wonko

#86 LeMOGO

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Posted 14 February 2011 - 07:25 PM

I fear that less experienced peeps may think that in the MBR you can write the addresses of EITHER a "primary" or a "secondary" partition.

I wasn't thinking along those lines. It should be clear from the companion map + graphics, but I agree with you.
I'll look into it.

Thank you.

#87 LeMOGO

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Posted 15 February 2011 - 05:35 AM

I fear that less experienced peeps may think that in the MBR you can write the addresses of EITHER a "primary" or a "secondary" partition. :( (being both a kind or type of "partition" whilst the very name of "sub-partition" makes easier to understand that it is NOT a "partition" with the "same dignity" as a "primary partition" or as an "Extended partition"). :wheelchair:


If your logic is that secondary might be understood as non-primary and used as "the other type" to create when creating a partition not "primary", then you are right. Secondary could be seen as the counterpart to primary in the MBR's partition table.
I agree to the above, so, "sub-partition" (intra-extended partition) is more appropriate to relate to actual partitions (not volumes) located within an extended partition. Given that a partition can not at the same time be a sub-partition, we can avoid some confusion with the "sub-partition" terminology. :)

A partition by definition does not relate to something abstract but rather to a grouping of physical sectors. One could argue that the grouping itself is a logical one even though it groups physically successive sectors. But then, primary partitions, viewed like that, would also be logical grouping and qualify as "logical partitions".
Or, one could argue that CHS boundaries are not true boundaries nowadays, and a sector's address may itself be logical (whether CHS or LBA), so if the sector addressing is logical, the grouping created using such an addressing is only possible along logical boundaries, not physical ones, making the partitioning a logical thing. But then, what would you say of early drives where the boundaries were along physical components? Besides, that would make primary partitions also qualify as "logical partitions".
Both of the above would still be true if we were to consider the grouping of sectors as a "volume" rater than a "partition".
A logical volume is a logical grouping of partitions into a unit (or volume). It does not have to exist along partition volumes, but with DOS being "simple", we had "volume = sub-partition", so the term logical volume was used to refer to the sub-partitions. Since the term has been "abused" for so long, I guess it's O.K. to use it, as long as one realizes that a volume is NOT a partition.

So, we're left with "sub-partition" to refer to the actual partition that the volume is made out of.

That should avoid any confusion and define things properly. If anyone has an objection against this logic, please shoot at it, but also propose one.

#88 LeMOGO

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Posted 15 February 2011 - 06:38 PM

Still no janitorial input?

Would janitors be part of the #2 subcategory of the "possible" 3rd category below?

In a forum, you are either a student or a teacher. I don't believe in any 3rd category. You either learn, or explain (some people just express their feelings, which is some times good but often inappropriate and useless). Even when you are a user having a problem, you explain your problem, then people that can help you learn about it so they can in turn explain to you what to do, at which point, you revert to the role of learner one more time. This is the ongoing dynamic of forums.

In this particular topic, we are interested in what has to go on in one's mind when approaching boot issues. At some point or the other, the rubber has to meet the road and generate some traction. Applications need to be mentioned and counsel given as to the benefits, strengths, weaknesses and application of the various software introduced to the readers.


Or a critic (3). :cheers:

Which can be divided in three categories:

  • critics that critic other people work and nothing else
  • critics that critic other people work and continuously hint about other people's shortcomings and still contribute nothing
  • critics that critic other people work and try to produce something (not necessarily related to the critics made)

:whistling:
Wonko


I hope that they are not and that we will be gaining traction soon.

#89 Wonko the Sane

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Posted 15 February 2011 - 06:56 PM

So, we're left with "sub-partition" to refer to the actual partition that the volume is made out of.

That should avoid any confusion and define things properly.

:cheers:

Just for the record, check the confusion this apparently innocent (but actually easily misleading) sentence has IMHO created:
http://neosmart.net/...or-not-the-mbr/
http://technet.micro.../cc749177(WS.10).aspx
What is written:

Bootsect.exe updates the master boot code for hard disk partitions to switch between BOOTMGR and NTLDR.

What people usually read:

Bootsect.exe updates the master boot record.


The good MS guys, to easen things ;) as usual :whistling: , have added to 7 a /mbr switch:
http://technet.micro.../dd744577(WS.10).aspx
that actually does refresh the MBR code.

Since the stoopid board parser doesn't like brackets, or because the stoopid MS guys love to use them in URL's, the above links to technet are not clickable, copy and paste:
Vista bootsect.exe:
http://technet.microsoft.com/en-us/library/cc749177(WS.10).aspx
7 bootsect.exe:
http://technet.microsoft.com/en-us/library/dd744577(WS.10).aspx

:thumbup:
Wonko

#90 LeMOGO

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Posted 15 February 2011 - 08:13 PM

The article in the 1st link itself could confuse people. It is not clear IMO (though it points to the problem accurately). The comments on the page may prove the suspicions some have about the origins of the confusion (well meaning people who try to make everybody's life easier - read "keep people ignorant" [so *we* can rule]).
It makes me think of people that suggest that we should all just "use fbinst and be done with it".
Conspiracy maybe? :cheers:

It just confirmed what I said (and I paraphrase):


"you are on your own".
you need to know what it's about, so you can sort out what they (any well meaning confused person) will certainly confuse you about.
"you, are on your own".

You are better off learning what's what!

-----------------------------------------------------------------------------------

I plan on mapping the various utilities (and their switches) to the right locations on a table.
Coming soon at a reboot.pro page near you ...

#91 Wonko the Sane

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Posted 15 February 2011 - 08:28 PM

It makes me think of people that suggest that we should all just "use fbinst and be done with it".
Conspiracy maybe? :whistling:

For what it matters :thumbup: I can guarantee that maanu is in perfect good faith AND NOT part of any coonspiracy. ;)
And - to repeat myself - fbinst is actually a very good utility :cheers: BUT IMNSHO overkill for most cases/people.

:cheers:
Wonko

#92 LeMOGO

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Posted 15 February 2011 - 09:03 PM

For what it matters :thumbup: I can guarantee that maanu is in perfect good faith AND NOT part of any conspiracy. ;)

Glad to know that!
But then why?

And - to repeat myself - fbinst is actually a very good utility :whistling: BUT IMNSHO overkill for most cases/people.

No doubt. To repeat myself, it boots all my systems.
But then, what? :cheers:

#93 LeMOGO

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Posted 15 February 2011 - 11:33 PM

I'm sorry, I misquoted.
It's actually "But ... then, why?" (look at the end of wonko's signature)
So the second rhetorical question should also have been: "But ... then, what?" :cheers:

#94 LeMOGO

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Posted 16 February 2011 - 12:38 AM

For what it matters :whistling: I can guarantee that maanu is in perfect good faith AND NOT part of any conspiracy. :cheers:


Someone else seems to disagree with you: see here.

#95 LeMOGO

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Posted 16 February 2011 - 04:52 AM

I just read something strange: MBR partition.

Yes, one could say that a partition is a division, so any division is a partition, thus a sector which is a division, is a partition.
But ... then, why? :dubbio:

By convention, the master (main) boot record is kept in the very first sector of the disk (the one accessed with the lowest numbered address). The acronym MBR itself became synonymous of that location on the drive. It is a sector, a single unit of disk storage (the smallest one).
A disk partition by definition is a segmentation (along address boundaries) of the space on a disk drive. It is a group of sectors treated as one unit for the purpose of data storage and retrieval. That unit is managed according to a set format, by the use of a driver called the file system driver. For read/write purposes, the whole block can be viewed as "the storage" from the standpoint of an application. An application does not need to concern itself with the details of the specific sectors a given file is located on. That's the job of the file system and its driver. All the application needs to know is the file name. It simply specifies the file by name.
So, "the storage" is "where files are" as far as an application is concerned. It is one block. That block is made by grouping sectors into a space usable as "the storage". That's what a partition is: a group of sectors grouped together as one block for the purpose of storage/retrieval of data through requests made to a file system driver.

Since the whole block is managed though a single file system driver, if we want to manage "the storage" differently, we will need another driver, one that can do things "differently". But since the filing system is of a fixed structure, we will need a driver that understands it (can read and write according to the filing rules). And since the structure is fixed, if we need abilities not offered by a given structure, we will need to use a different one. The data structure used for filing is part of the file system. Each file system defines how, where, and, what can be stored. If we were to create a table with a column per parameter, the table resulting from the definition of one file system would look different from that of the other file systems. It would be clear that they are different, and that if we wanted to use different file systems (features), we would need to give each file system a separate block to manage. That is why we partition (divide) the drive into blocks (groups of sectors) called partitions.

A volume is a group of partions that are managed as single unit by the file system. The MBR can not be made a volume. Only partitions can.

The MBR can not be formatted (assigned a file system), and, can not be mounted as a volume (seen as storage by the operating system). The MBR is *not* a disk partition. There is no "MBR partition".

Sectors are grouped into partitions.
Partitions are grouped into volumes.
A volume can be made from a single or multiple partitions. When the volume contains only one partition, referring to the volume is the same as referring to the partition, but if we want to talk about the partition within the volume, we need to use the term "partition".
A partition is *not* a volume.

A volume is a container for partitions. A partition is a container for sectors. A sector is a container for bytes. A byte is a container for bits. A bit is a state manipulated as datum.
Each is specific.

#96 Wonko the Sane

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Posted 16 February 2011 - 09:57 AM

Partitions are grouped into volumes.


Oh, noes. :diablo: :blush:

Putting a volume as a "group of partitions is EXACTLY the opposite of the common use of "volume", as in "logical drive" or "drive" in the sense of whatever gets a drive letter, or "filesystem".

Until your last post we were at:
  • Disk=PhysicalDrive=Container for partitions
  • Primary partition = Volume=LogicalDrive=Drive
  • Extended paertiion= Container for one Volume or for one Volume and one or more sub-partition(s)
  • Sub-partition (inside Extended) = Container for a Volume
  • Volume=LogicalDrive=Drive=Filesystem

:dubbio:

:ph34r:
Wonko

#97 LeMOGO

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Posted 16 February 2011 - 03:12 PM

Until your last post we were at:

  • Primary partition = Volume=LogicalDrive=Drive
  • Sub-partition (inside Extended) = Container for a Volume


The above simply tell you that a volume can contain a single partition, just the same as an extended partition can contain a single Sub-partition. A partition table can also contain a single partition entry (if it uses only one entry instead of four).
What it does *not* tell you, is that a volume can contain multiple partitions, an extended partition can contain multiple Sub-partitions, and a partition table can contain multiple partition entries.
Yes, you can have one, in which case your lines are right, but that's not complete.


  • Volume=LogicalDrive=Drive=Filesystem

says that it is a logical drive.

Partitions are grouped as a block and assigned file systems, then the block is mounted as a volume accessible through a single mount point called a "Drive Letter", or Drive.

The DOS world (i.e. M$ Win...) does not make the distinction, but it exists. This is part of why there is so much confusion. No distinction.

It's actually like this:
  • Disk=PhysicalDrive=Container for partitions
  • Volume=mount point=LogicalDrive=Drive=Containner for Primary partition/Containner for Sub-partition/Containner for multiple "Primary" or "Sub-partition"
  • Extended partition= Container for one Volume or for one Volume and one or more sub-partition(s)
  • Sub-partition (inside Extended) = Container for a assigned as part of a Volume (which can contain one or more Sub-partitions)
  • Volume=LogicalDrive=Drive=Filesystem (group of [one] partition[s] treated as a unit before "format", then formatted together as a single block)

That is why you can create stripes and mirrors. You can take multiple partitions from even different drives and group them under one umbrella as "the storage", mount all these partitions together as one file system accessible unit. This is what gets assigned a "drive letter" in Windows. :cheers:

#98 LeMOGO

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Posted 16 February 2011 - 03:28 PM

:cheers: I just realized that I posted the question on the wrong thread. it should have been posted on "The boot process: a step by step approach to booting".
I guess we'll complete the discussion here and resume in teh original thread, unless of course, someone can fix my mess. (sorry! :) - please accept my apologies)

#99 Wonko the Sane

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Posted 16 February 2011 - 03:38 PM

Well, you have completely lost me. :cheers:

You have gone to Dynamic Volumes, spanned disks or whatever.

Till now we were in the "basic" realm.

You are now into a different one with filesystems (or Volumes) spanning over multiple partitions.

This will confuse most people IMHO:

Disk=PhysicalDrive=Container for partitions
Volume=mount point=LogicalDrive=Drive=Containner for Primary partition/Containner for Sub-partition/Containner for multiple "Primary" or "Sub-partition"
Extended partition= Container for one Volume or for one Volume and one or more sub-partition(s)
Sub-partition (inside Extended) = Container for a assigned as part of a Volume (which can contain one or more Sub-partitions)
Volume=LogicalDrive=Drive=Filesystem (group of [one] partition[s] treated as a unit before "format", then formatted together as a single block)


The previous was more around "physical" placement of things, the current is along "logical" grouping that can be OPTIONALLY performed and ONLY with some Operating Systems.

You only need to add that since 2K you don't strictly need drive letters for most drives as long as you have a single volume NTFS formatted, by using mountpoints and the mess is complete. :)

:cheers:
Wonko

#100 LeMOGO

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Posted 16 February 2011 - 04:03 PM

Well, you have completely lost me. :)

You have gone to Dynamic Volumes, spanned disks or whatever.

Till now we were in the "basic" realm.


We were discussing semantics and trying to clear the terminology.


This will confuse most people IMHO


That is what we are trying to avoid! IMO, not making the distinction between volume (which is a logical thing) and partition (which is a physical thing), and, blurring the lines, cause people to not understand that there are "other kinds of volumes". A volume is not a partition. And yes, some are "Dynamic".

You only need to add that since 2K you don't strictly need drive letters for most drives as long as you have a single volume NTFS formatted, by using mountpoints and the mess is complete.

Yep! Volumes get "mounted". A mount point is not a drive letter. But, ... if you think in terms of volume=drive letter, you will get lost when there is no drive letter. A drive letter was Microsoft's way of labeling mount points, it is merely a label. A label is a label, a mount point is a mount point, a volume is a volume, a partition is a partition, a boot record is a boot record. I think we are clear on the semantics now.

We'll retain "Sub-partition" for the partitions created inside extended partitions. :cheers:




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