# How to boot in RAID0 with kernel 2.6.0 (using ataraid) ?

## behd

Hi everyone,

After strugling to get my 2 SATA disks working in raid0 with kernel > 2.4.21,

I am having problem now with 2.6.0 aswell... In fact it seems that the /dev/ataraid have disapeared in 2.6.0 series and this cause problems...

When booting I receive this error msg (before kernel panic):

```
VFS cannot open root device "720a" or unknown-block(114,10)

Please check root option blah blah...
```

Root was correct in lilo.conf for > 2.4.21 (root = /dev/ataraid/d0p10), but what should I use now ?

My configuration:

```

P4G8X Deluxe (i7205 w/ Silraid 3112)

2x 60Gb Seagate SATA disk (ST380023AS) -> 1 raid array in raid0

```

Thanks for any information !

----------

## Helena

About S-ATA I don't know (there are other threads about that), but ataraid sure has disappeared... https://forums.gentoo.org/viewtopic.php?t=79317  :Sad: 

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## Crg

 *behd wrote:*   

> 
> 
> Root was correct in lilo.conf for > 2.4.21 (root = /dev/ataraid/d0p10), but what should I use now ?
> 
> 

 

As mentioned in many other threads about ataraid you should've used linux software raid.

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## Helena

 *Crg wrote:*   

>  *behd wrote:*   
> 
> Root was correct in lilo.conf for > 2.4.21 (root = /dev/ataraid/d0p10), but what should I use now ?
> 
>  
> ...

 Why do you say that? If you have a hardware RAID controller, possibly built-in into your MoBo (like on one of my machines) why shouldn't you use that? In my case I am even forced to because it's a multi-boot machine. Also, in 2.4 ataraid/pdcraid worked perfectly AFAIK.

----------

## behd

yep that's also my problem... I have already an other OS instaled...

If software raid and hardware raid use the same scheme to write to the disks, why not...

but I am absolutely not sure about that... (could sw raid be used as replacement for hw raid ??)

Also an other problem, it seems that software raid cannot be booted directly (and I have only 2 disks in my comp... so it would be stupid to buy a third one, just to boot [use of cd or floppy is also annoying, it could be acceptable as temporary solution but not as definitive one]).

> Also, in 2.4 ataraid/pdcraid worked perfectly AFAIK.

Yes but I've read and heard so much good things about 2.6.0 that I wished to test it too  :Very Happy: 

Well got my answer from an other thread and sadly it seems that answers are:

- No sw and hw raid are not compatible

- No you can't boot a raid0 partition in 2.6.0 (ataraid seems to have completly gone)

----------

## Crg

 *Helena wrote:*   

> 
> 
> Why do you say that? If you have a hardware RAID controller, possibly built-in into your MoBo (like on one of my machines) why shouldn't you use that?
> 
> 

 

Why are you unable to search and read previous posts on this forum?  Please do that.

Sure if you had a hardware RAID controller on your motherboard you would use that - but you were talking about ataraid.

----------

## Crg

 *behd wrote:*   

> 
> 
> - No you can't boot a raid0 partition in 2.6.0 (ataraid seems to have completly gone)[/b]
> 
> 

 

I boot raid0 in 2.6.0 all the time.

Yes ataraid is gone and a very good thing too.

Arjan van de Ven is looking at having a userspace device mapper app apparently to handle it, if or when that gets done who knows.

----------

## behd

 *Crg wrote:*   

> I boot raid0 in 2.6.0 all the time.

 

Yes but what kind of raid ? (pure softawre raid or raid with a dedicated controller card ?)

 *Crg wrote:*   

> Yes ataraid is gone and a very good thing too.

 

Why should it be a good thing ??? (maybe performance wasn't that good but at least we were able to use the pseudo hardware raid done by SI3112 controller).

 *Crg wrote:*   

> Arjan van de Ven is looking at having a userspace device mapper app apparently to handle it, if or when that gets done who knows.

 

Well I hope that someone will have enough time and knowledge to code something like silraid in 2.4.n series. Because without such support, it will means that people who have installed their OSs on SI3112 raid won't be able to switch to 2.6.n kernel or will have to re-install all OS  :Sad: 

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## Crg

 *behd wrote:*   

> 
> 
> Yes but what kind of raid ? (pure softawre raid or raid with a dedicated controller card ?)
> 
> 

 

md driver.

 *behd wrote:*   

> 
> 
> Why should it be a good thing ??? (maybe performance wasn't that good but at least we were able to use the pseudo hardware raid done by SI3112 controller).
> 
> 

 

Why is it a good thing?  Because too many people buy these controllers and want to use them thinking they are hardware RAID controllers.

These same people are using some partially written driver for them instead of using a mature, better performing driver (md).

----------

## Helena

 *Crg wrote:*   

>  *Helena wrote:*   
> 
> Why do you say that? If you have a hardware RAID controller, possibly built-in into your MoBo (like on one of my machines) why shouldn't you use that?
> 
>  
> ...

 Your response surprises me. It sounds like an accusation, is that right?

To keep you informed, I not only search and read posts all the time, but I also contribute to discussions. Your posts in this thread do not read like they're meant to help someone out. Please correct me if I'm wrong.

----------

## Crg

 *Helena wrote:*   

> 
> 
> To keep you informed, I not only search and read posts all the time, but I also contribute to discussions.
> 
> 

 

Then why do you imply you have hardware raid on your motherboard and talk about ataraid?

 *Helena wrote:*   

> 
> 
> Your posts in this thread do not read like they're meant to help someone out. Please correct me if I'm wrong.
> 
> 

 

I know they may not seem it but they are designed to help people out.

They have a simple message.

1) Don't waste your time on, or waste your money buying any card that claims to be raid but isn't.

2) Either buy a real hardware RAID card or use the md driver.

----------

## Moled

 *behd wrote:*   

> Hi everyone,
> 
> My configuration:
> 
> ```
> ...

 

this is not a hardware raid controller

there is no "ataraid" as of yet in 2.6

im booting off md raid 0 in 2.6

the only "true" sata hardware raid controllers supported are the 3ware ones:

 *Quote:*   

> CONFIG_BLK_DEV_3W_XXXX_RAID:                                                                                                                                                                 
> 
> 3ware is the only hardware ATA-Raid product in Linux to date.                                                                                                                                
> 
> This card is 2,4, or 8 channel master mode support only.                                                         
> ...

 

you have 2 options: stick with 2.4 untill ataraid gets into 2.6 in some form

or backup your partitions and swap to md

----------

## behd

 *Crg wrote:*   

> Why is it a good thing?  Because too many people buy these controllers and want to use them thinking they are hardware RAID controllers.

 

Well even if it's not real hw raid, this solution is still interesting:

- cheap price for raid (no dedicated controller, no scsi disks...)

- allow raid for multiple OS (if we except 2.6.0  :Laughing:  )

 *Crg wrote:*   

> These same people are using some partially written driver for them instead of using a mature, better performing driver (md).

 

yup but there's no software raid for Redmond OS  :Sad: 

-> either:

- I have raid for Windows and a kernel 2.4

- I use sw raid for linux and no raid at all for windows...

----------

## behd

 *Moled wrote:*   

> you have 2 options: stick with 2.4 untill ataraid gets into 2.6 in some form
> 
> or backup your partitions and swap to md

 

it'll be option 1 then... (except if someone know a way to do software raid for THE other OS).

btw. everyone seems to criticize ataraid but does someone have seen benchmark for:

- single disk

- ataraid raid0

- real hardware raid0

(or know the difference in terms of performance between those ?)

----------

## Crg

 *behd wrote:*   

> 
> 
> Well even if it's not real hw raid, this solution is still interesting:
> 
> 

 

No it isn't.

 *behd wrote:*   

> 
> 
> - cheap price for raid (no dedicated controller, no scsi disks...)
> 
> 

 

That makes no sense.  It isn't cheap.  You pay extra for buying something that is just an ide controller.

Cheap is getting a normal ide controller and using the md driver.

 *behd wrote:*   

> 
> 
> - allow raid for multiple OS (if we except 2.6.0  )
> 
> 

 

Unless you are sharing partitions, you should be able to use the windows sw raid driver that comes with the card for it's partitions and setup linux to use the md driver on the linux partitions.

If you you are shaing a partition get another non-raid disk and put files to share between OSs on that.

 *behd wrote:*   

> 
> 
> yup but there's no software raid for Redmond OS 
> 
> 

 

That's not entirely true.  There are on server versions.

 *behd wrote:*   

> 
> 
> - I have raid for Windows and a kernel 2.4
> 
> - I use sw raid for linux and no raid at all for windows...
> ...

 

or try the solution above.

----------

## Crg

 *behd wrote:*   

> 
> 
> btw. everyone seems to criticize ataraid but does someone have seen benchmark for:
> 
> - single disk
> ...

 

ataraid is a poor and expensive software raid solution.  The criticism and discussion is nothing to do with speed - it's about people getting confused/mislead by it's labelling and thinking that the card does raid.

It's also the fact the ataraid code that was available in the kernel was incomplete and pointless as linux has better, more mature raid software in the kernel already.

Comparing performance between single disk, software raid, and hardware raid would be a very long reply, in short:

Software and hardware would out perform single disk. 

With a decent cpu software raid in some cases can out perform hardware raid.

----------

## Helena

Well to me it seems that the discussion has drifted a little away from the point, which is that behd has a certain hardware set-up and is looking for the best way to utilize it under Gentoo Linux, taking perhaps some restrictions into account.

Crg, I don't want to argue with you anymore, but some of your statements are simply false. First let me confirm that ataraid is the terminology used by Gentoo. E.g. in the Gentoo install docs for RAID setups (ch.27 Gentoo on less common hardware) the term hardware ATA RAID is used for the Promise PDC20276 chip which I have. Next, there is a kernel module "ataraid" which has to be loaded in order for a RAID setup to work. Finally, the RAID array itself is must be addressed as /dev/ataraid/disc0/disc. I refer for example to a topic on this which I have been contributing to (https://forums.gentoo.org/viewtopic.php?t=79317).

Also, I must correct you on another point. For Windows operating systems, there is a software RAID-like disk management solution available, not only for servers but also for clients. Starting from Windows 2000 Professional the concept of dynamic disks was introduced, supporting striped as well as spanned volumes (like RAID-0 but more flexible). If you want fault tolerance (like RAID-1) then you indeed need a server product.

So again: provide help if you want, along with information that is hopefully correct and complete and please refrain from cricticism that is beside the point. Instead, you could tell us how that "md" solution should be implemented.

And to behd: I hope I was able to help you at least in some way, please feel free to continue if you need more information.

----------

## Crg

 *Helena wrote:*   

> 
> 
> Crg, I don't want to argue with you anymore, but some of your statements are simply false. First let me confirm that ataraid is the terminology used by Gentoo. E.g. in the Gentoo install docs for RAID setups (ch.27 Gentoo on less common hardware) the term hardware ATA RAID is used for the Promise PDC20276 chip which I have.
> 
> 

 

There is nothing to argue about.  I am right.

I don't care that the gentoo docs might incorrectly call ataraid "hardware ATA RAID".  That is a mistake they need to fix.

If you actually bothered searched these forums like I contine to suggest, you'll see I post information about the ataraid code and where you can go about looking at what I'm talking about.

If you bothered to look at the kernel configuration you'd notice

```

CONFIG_BLK_DEV_ATARAID     -  Support for IDE Raid controllers

CONFIG_BLK_DEV_ATARAID_PDC -  Support Promise software RAID (Fasttrak(tm))

CONFIG_BLK_DEV_ATARAID_HPT -  Highpoint 370 software RAID

```

If you bothered to search google etc.... in fact if you had simply bothered to do any research whatsoever before accusing people of being wrong....

 *Helena wrote:*   

> 
> 
>  Next, there is a kernel module "ataraid" which has to be loaded in order for a RAID setup to work.
> 
> 

 

so you have to load a kernel device mapper and that is supposed to prove what?

You also have to load the md raid driver and personalities to use the native linux raid.

 *Helena wrote:*   

> 
> 
>  Finally, the RAID array itself is must be addressed as /dev/ataraid/disc0/disc.
> 
> 

 

And what's that supposed to prove?  That it is hardware!?  For native linux software raid you have to address it as /dev/md0.  Not very interesting.

 *Helena wrote:*   

> 
> 
> Also, I must correct you on another point. For Windows operating systems, there is a software RAID-like disk management solution available, not only for servers but also for clients. Starting from Windows 2000 Professional the concept of dynamic disks was introduced
> 
> 

 

Okay so I was wrong about windows supporting raid.  I only look after servers and the last workstation release I used was probably NT 3.51.

So the problem is solved.

Use windows raid solution for it's partitions and native linux software raid for linux.

----------

## behd

 *Crg wrote:*   

> No it isn't.

 

depends of the point of view...

 *Crg wrote:*   

> 
> 
> That makes no sense.  It isn't cheap.  You pay extra for buying something that is just an ide controller. Cheap is getting a normal ide controller and using the md driver.
> 
> 

 

bah, I am no more the hardware freakz that I used to be but it seems that most recent mb with SATA controllers have such chipset (promise, SI3112, etc...).

And yes, I was sharing partition... even if it's not mandatory (I could buy a third drive or use a network drive), it's still very comfortable to be able to access windows partition from linux.

 *Crg wrote:*   

>  *behd wrote:*   
> 
> yup but there's no software raid for Redmond OS 
> 
>  
> ...

 

My mistake (by ignorance)... I had heard of dynamic disk but never investigated what it was supposed to do... 

 *Crg wrote:*   

> or try the solution above.

 

Well switching to software raid could be solution but it means full re-install of windows and backup & restore of linux (pffff... just to switch to kernel 2.6.0... I think that I'll wait for support or will stick to my 2.4.0).

 *Crg wrote:*   

> 
> 
> ataraid is a poor and expensive software raid solution. The criticism and discussion is nothing to do with speed - it's about people getting confused/mislead by it's labelling and thinking that the card does raid.
> 
> 

 

and it does raid (ouch I already hear the flames coming back)... software raid but common raid for all OS...

 *Crg wrote:*   

> 
> 
> It's also the fact the ataraid code that was available in the kernel was incomplete and pointless as linux has better, more mature raid software in the kernel already. 
> 
> 

 

I do not agree with you here (not about the facts but about the meaning).

What it seems that you are trying to say is: "Do not use such technology because it's not mature and there's other way to do it as well".

So with such argument everyone would be using cable modem instead of adsl...

(in the early year of adsl, especially with usb modem, drivers were far to be mature and efficient compared to the proofed way to connect with cable modem (dhcp)).

Code is maybe incomplete for the moment but at least someone started to implement it and it was working (it seems that it even works almost as well as md because you do not criticize speed or cpu consumption or... but just the commercial argument from mb producer and the implementation of the drivers). I believe that there will be lot of improvement with time...

 *Helena wrote:*   

> Well to me it seems that the discussion has drifted a little away from the point

 

np, that's also the goal of a forum: exchanging point of view  :Very Happy: 

 *Helena & crg wrote:*   

> 
> 
> Crg, I don't want to argue with you anymore...
> 
> There is nothing to argue about. I am right. 
> ...

 

LoL, you are incredible guyz... peace, it's xmass & bnew year season  :Laughing: 

Thanks to both of you for your valuable feedback, I learned a few things...

Happy new year !

[edit]

hehe I was following 2 threads at the same time, but I got a very interesting answer from Heretic (which have the same opinion as crg but argumented with technical details)

https://forums.gentoo.org/viewtopic.php?t=111300&start=50

----------

## Crg

 *behd wrote:*   

> 
> 
> bah, I am no more the hardware freakz that I used to be but it seems that most recent mb with SATA controllers have such chipset (promise, SI3112, etc...).
> 
> 

 

Yeah it does come on a lot of motherbaords nowadays, but it's all about sticking a label on.

No real benefits except to confuse people  :Smile: 

 *behd wrote:*   

> 
> 
> And yes, I was sharing partition... even if it's not mandatory (I could buy a third drive or use a network drive), it's still very comfortable to be able to access windows partition from linux.
> 
> 

 

In that case you'll just have to wait a short while till someone comes up with a user friendly way to use the device mapper for you.

 *behd wrote:*   

> 
> 
> Well switching to software raid could be solution but it means full re-install of windows and backup & restore of linux (pffff... just to switch to kernel 2.6.0... I think that I'll wait for support or will stick to my 2.4.0).
> 
> 

 

You should be able to just use the promise driver for windows, and linux software raid for linux - would mean a reinstall of linux though which is not optimal, but then at least you would have easier upgrade options, more data security, probably faster, and if you're using ext2/3 you'll have the chance to format your disk is a better way for raid (mkfs using strides etc) which you probably haven't done this time around  :Wink: 

 *behd wrote:*   

> 
> 
> and it does raid (ouch I already hear the flames coming back)... software raid but common raid for all OS...
> 
> 

 

Well that's the point - the card doesn''t do raid.  The driver does.

 *behd wrote:*   

> 
> 
> I do not agree with you here (not about the facts but about the meaning).
> 
> What it seems that you are trying to say is: "Do not use such technology because it's not mature and there's other way to do it as well".
> ...

 

One of the things RAID is often used for is data reliability, ataraid code that I've seen does not have this.

What my point is there is a better way of doing things.

 *behd wrote:*   

> 
> 
> Code is maybe incomplete for the moment but at least someone started to implement it and it was working (it seems that it even works almost as well as md because you do not criticize speed or cpu consumption or...
> 
> 

 

I don't criticize it because I haven't done extensive enough testing.

My opinion, ie not fact, is that it wouldn't perform nearly as well as md.  This is supported in part by the comments in line 395 on linux/drivers/ide/raid/hptraid.c (and also in pdcraid.c).

```

Later on, online/offline checking and performance needs adding */

```

It's also support by the fact that these drivers are very incomplete and haven't even been finish let alone tuned for performance.

 *behd wrote:*   

> 
> 
> Thanks to both of you for your valuable feedback, I learned a few things...
> 
> Happy new year !

 

Happy new year to you too  :Smile: 

----------

## Crg

 *Helena wrote:*   

> 
> 
> refer for example to a topic on this which I have been contributing to (https://forums.gentoo.org/viewtopic.php?t=79317).
> 
> 

 

What I find most interesting about that thread is you yourself quote from the linux kernel configuration menu about 3ware being the only hardware ide raid controller available and yet you mustn't have read it.

----------

## greg32

Lets see guys.  We all have different points of view.  But the fact is, this guy wants support for his onboard raid chip so that he can use it in the 2.6 kernel.  Some of the above suggestions won't work.  

1. Windows dynamic disks won't work on the disk that the o/s resides on.  So he would need another hard drive, with windows sitting on a single non raided disk.  Not a good option.  

2. The highpoint/promise raid controllers may not be true hardware raid, this is a fact that echoes all over these forums and the web.  But, they certainly give good performance.  A single wd 80 gig drive with 8mb cache gives a max read/write of around 45mb/s.  My three wd 80 gig drives in raid0 on my highpoint rocket raid controller (pci card) gives me close to 100mb/s max.  Using the 2.4.X kernel drivers for it, I still get around 88 mb/s from my calculations (using dd and time, and working it out).  That is good.

3. You can not use your controller (highpoint or promise) and set it up in the bios as a raid0 array, and use it in windows as a raid0, and then go into linux and then try to set up the native s/raid with normal partitions.  It will bork the array, and your windows all of a sudden does not work.  I tried setting it up in Windows as a raid, all was good, and then went into linux, just for a trial to set up software raid, and partitioning the drives completely stuffed everything up.  If someone has a proven way of doing it without toucing my windows system, I will give it another go, but I don't see this working well.

4. And when it comes to raid0 reliability, be it software linux, software controller, of hardware controller, where is the reliability?  Nowhere, in none of them.  One drive fails, that is it, data gone, byby, not to be seen again.

Lets see though - promise/highpoint controllers are not true hardware raid, so they are no good!  They suck, and people should not use them is the attitude of crg.  That said, why don't I go all over these forums, and the first person who posts that "their 800mhz pentium 3 system is not performing too well, what can I do about it?" suggest to them they should piss their crappy system off and get a decent proper system like a 3.2 P4, or AMD3200/64.

Or, someone says their hdparm output for their single 7200rpm ata100 drive is crappy, what could I tweak???> tell them to go and get a proper harddrive, like a new scsi drive and controller.  Or get three or four, and raid them!!!!!!!!!$$$$$$$$$$$$$$$$$$$$4

I could go on, but it is irrelevant.  We all have the systems we have, and use them how we want.  And to say that the 2.6 kernel does not support these software raid ata controllers is a good thing, well that is stupid.  Linux, to survive, needs to support as much hardware as they can.  The general population are more and more using these controllers, and getting good results from them (I am very happy, and had software raid in linux working as well, with very little difference between them).  The future is only going to be better, with uber fast sata drives (much faster than the crap sata we have now) and pci-express, and very fast ata controllers, using these ataraid controllers all over the place.  

Anyway, enough of a rant.  Behd, I too hope support comes in 2.6 soon, because I want to keep using my system how I have it now, with a simple upgrade to the next kernel.

----------

## Helena

 *greg32 wrote:*   

> Lets see guys.  We all have different points of view.  But the fact is, this guy wants support for his onboard raid chip so that he can use it in the 2.6 kernel.  Some of the above suggestions won't work.  
> 
> 1. Windows dynamic disks won't work on the disk that the o/s resides on.  So he would need another hard drive, with windows sitting on a single non raided disk.  Not a good option  
> 
> 

 

Thanks for your support. BTW I wasn't suggesting that behd should use dynamic disks, only that Windows does support RAID. I agree, I still hope the 2.6 kernel will provide it later on. And true, I'm still satisfied with the perfomance of my "poor man's" RAID-0 setup (under Windows). I just cannot afford an expensive solution, and Linux software RAID is impossible for Behd & me, as you pointed out clearly.

----------

