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JanErik
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PostPosted: Fri Jun 20, 2003 1:38 pm    Post subject: RAID 0 shouldn't be called RAID? Reply with quote

Just started thinking about that... RAID mean Redundant Array of Inexpensive Disks... but RAID 0 (striping) is not redundant, compared to RAID 1 (mirroring).
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puggy
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PostPosted: Fri Jun 20, 2003 2:23 pm    Post subject: Reply with quote

[EDIT]
ALERT: Retarded Puggy in this thread. Look at my post near the end for explanation....
[/EDIT]

I think you'll find that RAID stands for Redundant Array Of Independant Disks. RAID 0 to me suggests RAID off, which it basically is.

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PostPosted: Fri Jun 20, 2003 2:33 pm    Post subject: Reply with quote

I don't care if it's technically wrong to call it RAID - it's fast and that's what matters to me.

oh yeah and I of course have one :)
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PostPosted: Fri Jun 20, 2003 2:40 pm    Post subject: Reply with quote

I was foolish not to go for the RAID version of my motherboard. I didn't know much about RAID at the time so I thought I wouldn't need/want it... how wrong could I have been? :roll: :D Atleast I have 133 ATA.
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PostPosted: Fri Jun 20, 2003 2:43 pm    Post subject: Reply with quote

port001 wrote:
I was foolish not to go for the RAID version of my motherboard. I didn't know much about RAID at the time so I thought I wouldn't need/want it... how wrong could I have been? :roll: :D Atleast I have 133 ATA.


I don't use the actual RAID features of my motherboard. I.e. It's effectively just a disk controller. My server has my 2 big disks in it so thery always accessibe by everyone. RAID is just unnecessary for me really.

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PostPosted: Fri Jun 20, 2003 2:49 pm    Post subject: Reply with quote

puggy wrote:
I think you'll find that RAID stands for Redundant Array Of Independant Disks. RAID 0 to me suggests RAID off, which it basically is.

Puggy


Well it once did mean Inexpensive.

Quote:
<storage, architecture> (RAID. Originally "Redundant Arrays
of Inexpensive Disks") A project at the computer science
department of the University of California at Berkeley,
under the direction of Professor Katz, in conjunction with
Professor John Ousterhout and Professor David Patterson.

Quote:
The original ("..Inexpensive..") term referred to the 3.5 and
5.25 inch disks used for the first RAID system but no longer
applies.


Source

And yeah it is a bit incorrect to call it redundant for RAID 0, I agree.
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PostPosted: Fri Jun 20, 2003 3:51 pm    Post subject: Reply with quote

port001 wrote:
I was foolish not to go for the RAID version of my motherboard. I didn't know much about RAID at the time so I thought I wouldn't need/want it... how wrong could I have been? :roll: :D Atleast I have 133 ATA.


Kernel RAID > MOBO RAID (this is really software RAID - and it's crap compared to the kernel implementation)

You did not make a bad decision - actually you made a wise and intelligent decision, save your money.

btw if you really insist most of those mobos can be hacked in software to go RAID since it's the same controller - only the firmware is different (sometimes you need a few resistors attached to the controller as well - depends on the model) - either way it's still crap.
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PostPosted: Fri Jun 20, 2003 3:54 pm    Post subject: Reply with quote

Lovechild wrote:
port001 wrote:
I was foolish not to go for the RAID version of my motherboard. I didn't know much about RAID at the time so I thought I wouldn't need/want it... how wrong could I have been? :roll: :D Atleast I have 133 ATA.


Kernel RAID > MOBO RAID (this is really software RAID - and it's crap compared to the kernel implementation)

You did not make a bad decision - actually you made a wise and intelligent decision, save your money.

btw if you really insist most of those mobos can be hacked in software to go RAID since it's the same controller - only the firmware is different (sometimes you need a few resistors attached to the controller as well - depends on the model) - either way it's still crap.


I'm not sure that's true. My motherboard (Abit AT7 Max-2) has an onboard highpoint controller. It also has a standard IDE channels chipset seperate from that. I wanted the RAID so I could have a lot of disks attached if I so wished.

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PostPosted: Sun Jun 22, 2003 6:21 pm    Post subject: Reply with quote

puggy wrote:
I think you'll find that RAID stands for Redundant Array Of Independant Disks. RAID 0 to me suggests RAID off, which it basically is.

Puggy


Sorry for being pedantic, puggy, but:
Quote:
In 1988, a paper was published which made the case that using a number of small, inexpensive disks could give higher performance and reliability than using a large expensive disk, at a lower cost. The paper was by Patterson ...., Gibson, and Katz, titled ``A Case for Redundant Arrays of Inexpensive Disks (RAID),'' published in the Proceedings of ACM SIGMOD (Special Interest Group on Management of Data) '88. [emphasis is mine]

From this source, but I am sure you will find many others.

BTW, your mobo controller did give you two more IDE channels, but I think you would have better luck treating them just as that---extra IDE channels, and not try the kernel "hardware" RAID drivers for them. So the same thing could be accomplished with an IDE PCI card---just depends how much more expensive the +raid mobo is than a regular mobo, and if you need that extra PCI slot.
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PostPosted: Sun Jun 22, 2003 8:28 pm    Post subject: Reply with quote

Somewhat straying from the topic, I have an ASUS A7V sitting in my server right now, which used to be my workstation. The greatest thing about that mobo was it's ATA/100 onboard controller. Big deal, you say? Well, it also had a separate ATA/66 controller. That's right, it had 4 IDE ports on the board. As of now, I think it has 1 optical disk and 4 hard drives. Doesn't have RAID, but I got the thing in the Summer of 2000. Not a bad board for so long ago.
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PostPosted: Sun Jun 22, 2003 10:36 pm    Post subject: Reply with quote

puggy wrote:

I'm not sure that's true. My motherboard (Abit AT7 Max-2) has an onboard highpoint controller. It also has a standard IDE channels chipset seperate from that. I wanted the RAID so I could have a lot of disks attached if I so wished.


The highpoint one is a software raid setup - ie they have BIOS code so it looks and pretends like a RAID controller but all the work is done by the driver.

The ataraid driver in the linux kernel, last time I had a look at it, had the bare minimum functionality to be able to use promise/highpoint, ie can read disk setup from BIOS and read and write to the disks, but no error handling, optimisations, no disk offline/online checking, etc...

The Linux software raid is on the other hand, is mature, faster, and has more functionality.
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PostPosted: Mon Jun 23, 2003 12:11 pm    Post subject: Reply with quote

Woland wrote:
puggy wrote:
I think you'll find that RAID stands for Redundant Array Of Independant Disks. RAID 0 to me suggests RAID off, which it basically is.

Puggy


Sorry for being pedantic, puggy, but:
Quote:
In 1988, a paper was published which made the case that using a number of small, inexpensive disks could give higher performance and reliability than using a large expensive disk, at a lower cost. The paper was by Patterson ...., Gibson, and Katz, titled ``A Case for Redundant Arrays of Inexpensive Disks (RAID),'' published in the Proceedings of ACM SIGMOD (Special Interest Group on Management of Data) '88. [emphasis is mine]


Sorry, but straight from the horses mouth...
http://www.highpoint-tech.com/techterms.htm#r
:-D

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PostPosted: Mon Jun 23, 2003 12:15 pm    Post subject: Reply with quote

Crg wrote:
puggy wrote:

I'm not sure that's true. My motherboard (Abit AT7 Max-2) has an onboard highpoint controller. It also has a standard IDE channels chipset seperate from that. I wanted the RAID so I could have a lot of disks attached if I so wished.


The highpoint one is a software raid setup - ie they have BIOS code so it looks and pretends like a RAID controller but all the work is done by the driver.

The ataraid driver in the linux kernel, last time I had a look at it, had the bare minimum functionality to be able to use promise/highpoint, ie can read disk setup from BIOS and read and write to the disks, but no error handling, optimisations, no disk offline/online checking, etc...

The Linux software raid is on the other hand, is mature, faster, and has more functionality.

My motherboard has a big fat chip on it marked highpoint, its a RAID chip.
Quote:


btw if you really insist most of those mobos can be hacked in software to go RAID since it's the same controller - only the firmware is different (sometimes you need a few resistors attached to the controller as well - depends on the model) - either way it's still crap.


It was this bit I was disputing sorry. I'm pretty sure that non-RAID motherboards don't come with RAID chips on-board and unused. certainly they wouldn't have the IDE connectors anyway.

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PostPosted: Fri Jun 27, 2003 10:55 am    Post subject: Reply with quote

puggy wrote:
Crg wrote:

The highpoint one is a software raid setup - ie they have BIOS code so it looks and pretends like a RAID controller but all the work is done by the driver.

The ataraid driver in the linux kernel, last time I had a look at it, had the bare minimum functionality to be able to use promise/highpoint, ie can read disk setup from BIOS and read and write to the disks, but no error handling, optimisations, no disk offline/online checking, etc...

The Linux software raid is on the other hand, is mature, faster, and has more functionality.

My motherboard has a big fat chip on it marked highpoint, its a RAID chip.


You could stick a SCSI sticker on the chip and it wouldn't make it a SCSI chip.

Maybe my explaination isn't clear above or something - but it's marketed as a RAID chip (along with loverly stickers and RAID labels) but in reality its just straight forward IDE controller.

The only differences with the highpoint and lowend promise "raid" chipsets and an "normal" IDE card is a BIOS which will allow you to setup a RAID configuration that is saved on the first part on the harddrives.
This configuration is then read by the software driver in which all the RAID functionality is implemented.

If you don't believe me have a quick read of
http://linux.org.mt/article/ata-raid (which I found with a quick search of google), in particular the paragraph titled "Hardware or Software RAID".

and if you don't believe him have a quick gander at /usr/src/linux/drivers/ide/raid/, in particular functions such as hptraid1_read_request in hptraid.c.
If this dealing with a true hardware RAID system it wouldn't be working out which disk to read off/write to etc...
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PostPosted: Fri Jun 27, 2003 1:32 pm    Post subject: Reply with quote

The independent/inexpensive are interchangable now...so there's no use fighting. :lol:

I justify RAID 0 being RAID as the levels having increasing degrees of reliability. So RAID 0 would be the least reliable. It's inclusion is due to striping, no? All other levels use striping except for 1, right?


Last edited by mlang on Fri Jun 27, 2003 2:07 pm; edited 1 time in total
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PostPosted: Fri Jun 27, 2003 1:44 pm    Post subject: Reply with quote

Crg wrote:
puggy wrote:
Crg wrote:

The highpoint one is a software raid setup - ie they have BIOS code so it looks and pretends like a RAID controller but all the work is done by the driver.

The ataraid driver in the linux kernel, last time I had a look at it, had the bare minimum functionality to be able to use promise/highpoint, ie can read disk setup from BIOS and read and write to the disks, but no error handling, optimisations, no disk offline/online checking, etc...

The Linux software raid is on the other hand, is mature, faster, and has more functionality.

My motherboard has a big fat chip on it marked highpoint, its a RAID chip.


You could stick a SCSI sticker on the chip and it wouldn't make it a SCSI chip.

Maybe my explaination isn't clear above or something - but it's marketed as a RAID chip (along with loverly stickers and RAID labels) but in reality its just straight forward IDE controller.

The only differences with the highpoint and lowend promise "raid" chipsets and an "normal" IDE card is a BIOS which will allow you to setup a RAID configuration that is saved on the first part on the harddrives.
This configuration is then read by the software driver in which all the RAID functionality is implemented.

If you don't believe me have a quick read of
http://linux.org.mt/article/ata-raid (which I found with a quick search of google), in particular the paragraph titled "Hardware or Software RAID".

and if you don't believe him have a quick gander at /usr/src/linux/drivers/ide/raid/, in particular functions such as hptraid1_read_request in hptraid.c.
If this dealing with a true hardware RAID system it wouldn't be working out which disk to read off/write to etc...


I understand what your saying. Your saying that you can probably use the normal IDE channels on a motherboard to get the same RAID effect as what I have. I'm not usnig my actual RAID functionality anyway so it doesn't matter to me, it's the extra IDE sockets that I wanted. Thanks for clearing that up mate. :-D

Puggy
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PostPosted: Fri Jun 27, 2003 6:23 pm    Post subject: Reply with quote

I am glad you finally see the light, puggy, we were giving up on you :wink: As somone who has spent much time with these "RAID" chips, I can state fairly confidently that Linux software RAID has consistantly given much better performance---even compated with factory suplied drivers.

And sorry, but you quoted marketing hype in support of your "Independant" position, while I sited the actual paper where RAID was introduced in support of my "Inexpensive" stance. I would just let this go but it is an issue of such extereme crucial importance.
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PostPosted: Fri Jun 27, 2003 6:30 pm    Post subject: Reply with quote

Woland wrote:
I am glad you finally see the light, puggy, we were giving up on you :wink: As somone who has spent much time with these "RAID" chips, I can state fairly confidently that Linux software RAID has consistantly given much better performance---even compated with factory suplied drivers.

And sorry, but you quoted marketing hype in support of your "Independant" position, while I sited the actual paper where RAID was introduced in support of my "Inexpensive" stance. I would just let this go but it is an issue of such extereme crucial importance.


Yeah. I'm not using my RAID so the performance doesn't really effect me. Some servers I was working on last summer had proper (compaq smart-start type systems) hardware RAID. That was pretty sweet to use. :-D

Well, their independant, and their inexpensive. Let's petition for them to rename it RAIID - Redundant Array Of Inexpensive, Independant Disks. :-D

Without getting back into this argument what exactly is the inexpensive bit relative too? I don't know of anything commercailly available which could replace a RAID array and hence be the "expensive" alternative.

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PostPosted: Fri Jun 27, 2003 7:37 pm    Post subject: Reply with quote

Lovechild wrote:
I don't care if it's technically wrong to call it RAID - it's fast and that's what matters to me.

oh yeah and I of course have one :)


I've read that Linux software RAID 0 is much slower than it's RAID 5, why not use RAID 5?
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PostPosted: Fri Jun 27, 2003 7:45 pm    Post subject: Reply with quote

dice wrote:
Lovechild wrote:
I don't care if it's technically wrong to call it RAID - it's fast and that's what matters to me.

oh yeah and I of course have one :)


I've read that Linux software RAID 0 is much slower than it's RAID 5, why not use RAID 5?


If your using RAID 0 your not using RAID at all hence the thread title. RAID 5 is a as much as 2 times faster as it stripes the disks. I don't require that kind of speed so I don't use it. Also if you lose 1 of your 2 hard drives in your array say you've lost 1 out of every 2 bits of your data. Which means, effectively you've lost ALL of your data instead of just half. This has never happened to me, but just to be safe...*tocuhes wood* :-D

Sweet new avatar Dice. I've got that original poster on the wall behind me. :-D

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PostPosted: Fri Jun 27, 2003 7:49 pm    Post subject: Reply with quote

puggy wrote:

If your using RAID 0 your not using RAID at all hence the thread title. RAID 5 is a as much as 2 times faster as it stripes the disks.


Isn't the definition of RAID 0 striping at block level w/o fault tolerance/redundancy?
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PostPosted: Fri Jun 27, 2003 7:56 pm    Post subject: Reply with quote

mlang wrote:
puggy wrote:

If your using RAID 0 your not using RAID at all hence the thread title. RAID 5 is a as much as 2 times faster as it stripes the disks.


Isn't the definition of RAID 0 striping at block level w/o fault tolerance/redundancy?


It appears I've been wrong about what RAID 0 is all along. Cheers man. I'm officially retarded.

This website gives good explanations
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PostPosted: Fri Jun 27, 2003 7:58 pm    Post subject: Reply with quote

puggy wrote:
mlang wrote:
puggy wrote:

If your using RAID 0 your not using RAID at all hence the thread title. RAID 5 is a as much as 2 times faster as it stripes the disks.


Isn't the definition of RAID 0 striping at block level w/o fault tolerance/redundancy?


It appears I've been wrong about what RAID 0 is all along. Cheers man. I'm officially retarded.


Lol - it's cool man, we all have those days! :D
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PostPosted: Fri Jun 27, 2003 8:00 pm    Post subject: Reply with quote

puggy wrote:
Sweet new avatar Dice. I've got that original poster on the wall behind me. :-D


RATM rawks :D Cool hair, too 8)
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PostPosted: Fri Jun 27, 2003 8:03 pm    Post subject: Reply with quote

mlang wrote:
Lol - it's cool man, we all have those days!:-D

This was a schoolboy error, can't believe I thought it seeing as I did several RAID installs on proper RAID hardware over the summer last year. *Shakes head*
dice wrote:
puggy wrote:
Sweet new avatar Dice. I've got that original poster on the wall behind me. :-D


RATM rawks :D Cool hair, too 8)


Cheers man. :-D Bit more scruffy now. Keep meaning to have it cut. Never enough time in the day.
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