Random Idiot Computer Question: Why C?

JohnnyBiggles

With all my knowledge (and lack thereof) of computer technology, a few seemingly minute things still make me ponder some of the basics overlooked... so here goes....

Why are computers so standardized as requiring the "C:" drive by default (as opposed to A, B, Q, etc.) to use as the operating directory? If I wanted to use, say "A" as my local operating drive (knowing well that I do not currently, nor ever will have a floppy drive), could I? Floppy drives are barely used anymore... but I guess my concern or question that made me think of all this is, what was/is the "B" drive and why is it never available? Is it? I can't ever recall seeing anything using a built-in or external "B" drive for it to exclude it from a choice of defaults even. Wouldn't it make sense to have your starting drive be "A" nowdays anyway? Especially since more and more drives are in systems along with mapped network drives? Do you think it will ever be so?

it_consultant

C: is just a standard. You will see a lot of XenApp servers whose boot drive is actually M: or something else. Some people use A: or B: thinking it might confuse attackers. Mainly, it just confuses admins. XenApp has a specific reason for not using C: but I forgot what it was. In that case you still install it with C: and they have a free utility that changes it.

RobertKaucher

I once installed a copy of Vista on my home PC with an SD card in the card reader and the installer assigned E to the system drive.

A and B in the Microsoft lineage are reserved due to convention from the days of backwards compatibility when A and B were there assigned to minidisks and floppy disks.

Drive letter assignment - Wikipedia, the free encyclopedia

awitt11

It was common to run A: and B: floppy drives, with one disk running your application and the other saving your work (when there was no HDD to save to). This was the setup in my grade school computer lab with Apple IIe and IIc+ (I think).

chopsticks

You just reminded those days I had in schools!

JDMurray

Many moons ago I used G: as the OS volume for all of my Windows 2000 servers. You'd be surprised how many app installers were hard-coded for C:\Windows and C:\Program Files folder. A lot of that has changed because of localization of multilingual Windows apps on international distributions of Windows. Hard-code "Program Files" into your app and it'll blow up on the German Windows where the folder is named "Programme." (I found that one out the hard way.) Disk volume letters seem to be the same world-over though.

dustinmurphy

I think it's more of a standardization than anything else. a: and b: are set aside for floppy drives... c: is set aside for system volume... d: is either a secondary partition or an optical drive... etc

I generally use s: as a network "shared" drive and u: as a network "user" drive.... just my standards...

Forsaken_GA

As others have mentioned, A and B are legacy reservations, and some programmers are lazy and make assumptions when it comes to C

Of course, once you get into the Unix world, you get rid of all this drive letter nonsense hehe

DevilWAH

years ago I stopped using C as the default drive,

I have always split my in to

C: OS
programs
E: document and user files
I: media files (video / music)

general split over separate physical disks.

And of course if you have a duel boot machine you can end up with lots of different configurations, and windows will chose a different letter if the first hard drive is already in use and you chose to install to a differerent partition.

As people have said using C: goes back to the days of having floppy disks, and is used still becasue its what people "expect". Some bad apps are hard coded to use it, however there is not standard that says the OS drive must be named C,

this is also true of using "program folder" or "windows folder" as long as you set them up when you install windows you could if you want change the name.

Microsfot ave simple chosen standard names to keep it consistence across devices, but there's nothing stopping you calling you program folder "running stuff" as long as you update your path and a few keys in the regstary.

dustinmurphy

DevilWAH wrote: »

years ago I stopped using C as the default drive,

...snip..

Would you mind explaining why? I understand keeping your OS/Programs separate from your user data, however that seems like an odd way of partitioning a drive... and/or a waste of multiple drives. The reason most people use a separate partition or drive for data is so that if the OS has to be reloaded... the data stays there.... BUT programs will still have to be re-installed... That sounds like a lot of extra work... for very little (if any) return.

On desktops/laptops.. I generally keep everything on a single partition.... whether in the office or at home (both places, I have a file server of some sort that allows me to store user files on a server that gets backed up.) On servers, I usually have 2 partitions (on a RAID array). One for OS/Programs... one for Data.

SteveLord

dustinmurphy wrote: »

Would you mind explaining why? .....

More organized to some, allows more flexibility in terms of doing backups, defragging or maintenance scans, etc. As well as keeping games in their own dedicated partition (more useful in the old days, but now many games write many essential files to the C: drive regardless.)

It's been a standard for my personal computers for 15 years now since my father originally educated me on it.

C: OS
Misc programs
E: Games (retail)
F: Steam Games
G: Storage

All of these are across multiple solid/hard drives as well.

dustinmurphy

That's an interesting approach. I'm not sure I can agree with the benefits... but to each his own.

I'm curious... how does that allow more flexibility in backups, defragging, etc? Again, I can see the benefit of separate partitions/disks for OS and Data, but how does installing games/programs on a separate drive improve the flexibility you talk about? I wouldn't think that performance gains would be much... especially if you have a SSD for your OS and a standard 7200RPM drive for the other drives. If you have to reload your OS, you have to re-install the games and programs anyways, so you will essentially have to wipe out 3 of your drives to get everything back up and running properly. That also doesn't account for the amount of configuration you have to do to get things to install on a separate location other than C:\Program Files. Again, seems like a lot of work with little to no gain.

Keep in mind, I'm not trying to say you're wrong... as you're NOT. I'm just wondering what benefits could be had by separating everything like that.

DevilWAH

dustinmurphy wrote: »

That's an interesting approach. I'm not sure I can agree with the benefits... but to each his own.

multiply drives help incress speed.

Program files and OS on 10K raid 0 WD raptors drives, fast access rates but cost of storage high, so go for files assessed by the OS.

Documents and media you dont need such fast speeds, any drive can keep up with playback of vidoes and opening doc's, and the user is never going to notice the fraction of a second in cress using a slower drive, and slower drives are much cheaper

splitting docs and media just makes organisation easier.

At the time I had 5 WD Raptors in 2 separate raids.

one for the OS and one for program files which also doubled as a temp area when video editing. Video editing is one of the few things I have found that does actuly show the benefit of fast drives. While aps might load faster once they are loaded they don't show a speed in-cress general. Video editing shows marked incress if it has a dedicated physical drive for temp working files. Also moving the paging file on to a separate physical disk (in my case it was the program disk) increases proformance. Any time two processes are trying to write to the same physical disk at the same time the proformace will fall of. this is the second reason to split up your data.

as well as the 5 WD drives I also had two 500gig drives (a few years back now) split between documetns and media.

but it was all about splitting the data to match the cost of different types of storage I had available. no point in putting films on storage that cost at the time £160 for 73gig. And splitting the work equal across the physical disks.

Forsaken_GA

DevilWAH wrote: »

Program files and OS on 10K raid 0 WD raptors drives, fast access rates but cost of storage high, so go for files assessed by the OS.

You know, I've heard of folks doing this before, but there's just no way I could put my personal computers OS running on a raid 0. A raid 10, sure, a raid 0, no way in hell, I'd be the guy who'd get lucky and have a drive crap out just as I was getting ready for something really important

SteveLord

dustinmurphy wrote: »

That's an interesting approach. I'm not sure I can agree with the benefits... but to each his own.

..s.nip.

Unfortunately, yes, games and apps would have to be reinstalled anyway. Would be nice if this was revamped in a future operating system eh? For those, it is more about organization above all else so I should have specified that the actual benefits are in the eye of the beholder and not so relavant like they use to be back in the FAT16/32 days. This could be beneficial when searching for files or performing maintenance scans as they could be more isolated. I could choose to backup only C: drive and it's essential OS files, instead of including games and other junk as well. Unless one wanted to go folder by folder by folder. The need for defragmenting would be less for those still on HDD-only systems since everything is divided.


Installing on another drive takes a few clicks to change it from c:\program files. So there is no real work there.

It really all comes down to preference. I just tried hit upon some potential perks.

Forsaken_GA wrote: »

You know, I've heard of folks doing this before, ...snip...

All the more reason to have a back up somewhere else, which you would likely have anyway even if you were on RAID10 right? If your computer bursts into flames one day, you’re screwed no matter what type of RAID was in it. RAID0 is really nice for photo/video editing where you’re constantly manipulating large files. I’ve used it ever since WD’s original 36GB Raptor drives, but I did stop it upon using 2 Vertex 3 SSDs. Given that they already had a risk of failure in their early firmware revisions, I didn’t want to increase that with RAID0 and seeing no real benefit to it anyway for my OS and games.

DevilWAH

Forsaken_GA wrote: »

You know, I've heard of folks doing this before, ...snip...

I have always seperated my OS/programs files (the non critical to replace) on to fast raid 0 and the documents / media Photos on to redundant storage.

I also have always in the past had two systems. Gaming rig that was kept lean and mean with little redundancy and all about proformance. didn't care if it fell over cause it was jsut for playing. and my work system that was kept backed up and the rest.

I was always playing with my gaming rigs so they fell over due mostly to my own stupidity every free weeks

Forsaken_GA

SteveLord wrote: »

All the more reason to have a back up somewhere else, ...snip....

It's not a matter of backups, and I understand the concept of RAID0 for speed, so I'm perfectly ok with the concept of using RAID0 for applications that need to make use of heavy disk I/O, but I can't recall many applications that require that I/O to take place on the OS drive. The concept of putting the OS drive on a RAID 0 scares the bejesus out of me, because there is one certainty in all of computer land - The hard drive *will* fail. I'm alot more tolerant of work drives or content drives being on less reliable media, since I religiously make backups to other sources, but increasing the chance that my box won't boot on purpose? Yeah, that's a risk that I'm not willing to take

DevilWAH

Forsaken_GA wrote: »

It's not a matter of backups, ...snip...

but its a case of it dont matter if the OS drive fails, get a new drive and reinstall, all you data is safe on a different drive. Would no consider if it for one moment in a company environment. But for a game PC thats getting rebuilt every 6 to 12 months the chances of the drive failing between rebuilds is quite low. In fact in 20+ years of builing PC's at home I have never lost data on a raid 0 or indeed any disk drive.

when i first got in to raid, using it on the OS drive changes a 140 boot time in to sub 50seconds. And becasue the paging file was also on the OS partition increased system response time as well by a noticeable factor.

I do agree these days with the huge ram volumes systems have and fast SSD drives usign raid on the OS does not give you the same level of proformance incress. (assuming you move page file to a faster spindle) but I do thinking people get caught up in relibility worries, I hammered hard drives, running video encoding almost 24/7 for many years which thrashes drives, and as I say never lost data to a fail drive.

SteveLord

Forsaken_GA wrote: »

The hard drive *will* fail.

Not a huge concern when one upgrades their computer every few years or less.

dustinmurphy

DevilWAH wrote: »

multiply drives help incress speed... snip...

Yes, I understand the benefits of a RAID array, however I don't understand the benefits of having multiple partitions on a single RAID volume for OS and Program Files.... my old "beast" machine had a RAID 0 with 4x 15k SAS drives (36G each)... and another RAID 0 2x 7200 SATA array for storage (yeah, I know... but I wasn't using it for important files that I couldn't use)

I could choose to backup only C: drive and it's essential OS files, instead of including games and other junk as well. Unless one wanted to go folder by folder by folder. The need for defragmenting would be less for those still on HDD-only systems since everything is divided.


Installing on another drive takes a few clicks to change it from c:\program files. So there is no real work there.

It really all comes down to preference. I just tried hit upon some potential perks.

I don't backup OS files... since if any of them have problems, it's likely that the OS will have to be reloaded, anyways. I also don't backup the "Program Files" folder. I would only backup user profiles and/or data partitions...

As I said before... to each his own... I'm just trying to understand why anyone would go through the extra work of separating it like you do.... if it works for you, great... but it still doesn't make sense for me.

You know, I've heard of folks doing this before, but there's just no way I could put my personal computers OS running on a raid 0. A raid 10, sure, a raid 0, no way in hell, I'd be the guy who'd get lucky and have a drive crap out just as I was getting ready for something really important

Certain situations allow for an OS to run on RAID 0. For instance... my "beast" computer ran OS AND storage on a RAID 0. Why? Well, because it was just a "fun" computer... and the OS was running on 4x 15k RPM SAS drives at 36G each. Disk I/O was AWESOME... I used it to convert my DVD's to MKV for use on my HTPC... and I could rip 2 DVD's at a time.... and encode to MKV in about 18 minutes... while on my laptop... it took 1.5 hours. The "storage" drive wasn't important, either. I didn't keep anything that I COULDN'T lose on it. It was more or less a large drive to keep the MKV's on before I transferred them to my NAS.

As a standard, however... I would not RAID 0 ANY drives... as the risk of loss is too much... but there are exceptions to the rule.

DevilWAH

dustinmurphy wrote: »

Yes, I understand the benefits of a RAID array, however I don't understand the benefits of having multiple partitions on a single RAID volume for OS and Program Files....

I would have OS and paging on one raid array and program and working directory on a second array. I agree no real point having seperate partitions on a raid 0 set up. Partitions I generally used on large slow "storage" media purely to make it easier for me.

There is an argument for increase proformance in using multiply partitions, however I have never seen any evidence of this, and you have to set split the disks in specific ways to achieve it. Remember this was back when SATA was a new kid on the block and 8mb cache on a drive was considered a lot.

Now partitioning is more about organising data rather than proformance issues.

RobertKaucher

Forsaken_GA wrote: »

... The hard drive *will* fail. I'm alot more tolerant of work drives or content drives being on less reliable media, since I religiously make backups to other sources, but increasing the chance that my box won't boot on purpose? Yeah, that's a risk that I'm not willing to take

RAID 0 doubles your chances of a drive failure.

DevilWAH

RobertKaucher wrote: »

RAID 0 doubles your chances of a drive failure.

In theory this should not be the case, if one drive has a MTBF of 10,000 hours lets say, two drives both have MTBF of 10,000 hours, so the probability of any one drive failing is still the same as before.

So the probability of any single drive in an array failing and taking out the arrays is no worse than storing all your data on a single physical disk with no redundancy.

What Raid 0 does not do is lower the chance of a drive failing, raid 1 of course does as the probability of two drives failing at the same time is very low, so in the case of two 10,000 hour MTBF drives in a raid 1 array, the array as a whole will sill have a MTBF of 10,000 hours of any one disk. Just in this case a single disk failer wont bring down the whole array.

but in both cases the MTBF for an error to occur in the array as a whole will continue to be the MBF for a single disk. increasing the numbers of disk does not make the disk less reliably.

Yes raid 0 doubles your changes of a failer, but if the probability of failer in a given time frame is very very low, lets say 0.0001% then to double this is still only 0.0002%.

a little in a little is a lot... a little in a lot is still a little.

Should you store critical/unrecoverable files on raid 0.. of course not, but I don't consider OS or program files as critical, I have install disks for them, or a disk image.

I also know I will rebuild a PC every 6-12 months which means the probability of me rebuilding is far in excess of a drive failing causing a rebuild.

I have to say though these days if i was to go raid again with 5 drives I would have them in a raid 5 set up

SteveLord

Given the questionable quality of the latest consumer HDDs, I would be very careful.

ChooseLife

JohnnyBiggles wrote: »

Why are computers so standardized as requiring the "C:" drive by default

You do realize you're making some of us feel old, right? And considering I'm in my late twenties, it's a really weird feeling...

JohnnyBiggles wrote: »

I can't ever recall seeing anything using a built-in or external "B" drive

There was a time when it was pretty standard for a personal computer to have two floppy drives. And I don't mean those new-tech small 3.5" floppies, that advanced technology came later...

DevilWAH

ChooseLife wrote: »

And I don't mean those new-tech small 3.5" floppies, that advanced technology came later...

now are we talking the 5 1/2 inch of 8 inch ones

Indeed back in the day most PC did not have a hard drive at all, so it was very common to have two drives as this was the only way to easily copy data, with out swapping disks in and out multiply times. With only one drive the PC would copy the first drive till its memory was full (64kbyte) then you would swap disks and it would right it out to the disk, then swap back so it could capture the next bit and swap, and so on. For a 720kbyte disk this is a lot of swapping. Also to read a 5 half inch floppy took a fair amount of time, copying to hard drive (if you had one) took a few minutes, and then you had another few minutes to wait to copy back ion to the new one. having two floppies meant you could stream from one to the other, halving the time to make a copy.

Even when hard drives came along there where both expensive for capacity and slow. So for a long time duel floppy's was the way to go. By the time the 3.5 inch came along the hard drives and memory specs of PC's had increased to the point where two drives was not needed.

So yes us old guys remember well the days of copy a:\*.* b:\

SteveLord

When I was a kid, I use to think the 5.25inch held more data because....well, it was bigger than a 3.5inch ! Duh!

JDMurray

It was the hard drive that killed the dual floppy configuration. You simply didn't need two floppies with either your programs or data (or both) loaded on to a hard drive. Not including a second floppy as a standard feature also reduced the manufacturer of a PC.

I didn't stop putting a 3.5" floppy drive into PCs I built until 3.5" USB floppy drives became inexpensive a few years ago. I'm still looking for a 5.25" USB floppy drive to archive my 1980's software library. I would use a 5.25" out of one of my old dinosaurs, but I'm sure the heads are all oxidized and would damage the discs.

JohnnyBiggles

DevilWAH wrote: »

So yes us old guys remember well the days of copy a:\*.* b:\

To be fair here, I'm not that young myself and definitely remember the whole two drive bit... in fact, I'll take it even further back to when cassettes were used as "external" storage media and programs! Much of my whole understanding of how Windows OSs work comes from using "IBM Compatible" machines before Windows 3.1 even existed and DOS commands to do everything. Windows Explorer?... Pshhh....nah... "a:\>DIR /W", bytch.

Anyway, I understand why it is this way, but my question really sorts out to be, why is it STILL such a standard? The A and B drives could be used for the OS or even removable media drives.. and we are WELL beyond those days where we use built-in floppy drives or have any need to RESERVE them automatically. Not even optical drives are reserved. They get assigned whatever is available. When will software/OS companies (and I guess hardware as well) make that change? Will they ever?

Asif Dasl

I don't think they will ever change C:\ It's ingrained in to our subconscious now. I came across a computer a few weeks ago, it was running Windows 7 and it listed the floppy drive in explorer - I was a bit taken aback, it's a while since I've seen a 3.5" floppy drive and had to double check the front of the computer... well what do you know, they are still about. Not many though.

Forsaken_GA

JDMurray wrote: »

It was the hard drive that killed the dual floppy configuration. You simply didn't need two floppies with either your programs or data (or both) loaded on to a hard drive. Not including a second floppy as a standard feature also reduced the manufacturer of a PC.

I don't even bother putting CD/DVD drives in boxes anymore. My USB external LG burner was one of the best purchases I've ever made for the rare times I need physical media, almost everything is done over the network these days.