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

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

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):

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

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Helena

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

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

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 · Guru Joined: 29 May 2002 Posts: 345 Location: London

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Helena

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Moled · l33t Joined: 09 Jul 2003 Posts: 635

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Helena · Posted: Mon Dec 29, 2003 6:56 pm Post subject:

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 · Guru Joined: 29 May 2002 Posts: 345 Location: London

behd · Apprentice Joined: 11 Feb 2003 Posts: 155

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

Crg · Guru Joined: 29 May 2002 Posts: 345 Location: London

greg32 · Posted: Tue Dec 30, 2003 10:46 pm Post subject:

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 · Posted: Wed Dec 31, 2003 10:28 am Post subject: