# How good is gentoo's raid support?

## RaceTM

heya,

I've been scouring the forums for a while looking for a concrete answer to this question, but every related thread I've seen has been inconclusive so I'm hoping someone can help me out.  Right now, on my Windows box, I have two sata drives in raid 0 running windows, and two ata133 drives running in raid 1 storing my important data.  All drives are running off of a Promise fasttrak TX2plus raid adapter.  Now this setup is perfect for me, asi it meets my needs and gives me  all the space I need.  I've been looking for a way to get windows 2000 and Gentoo to dual boot off this setup, and be able to keep the sae configuration (windows and linux booting off the sata drives, but being able to access the ata drives from both operating systems).  Most of the threads I have read indicate that at this time it's not possible to run gentoo on sata drives in raid, but some people seem to claim success.

What I'd like to know is wheteher or not it would be possible to get gentoo installed on this configuration, and if so, how?  Somebody mentioned putting a regular ata drive in their system and placing the boot partition on it..but I don't recall the details, or if it was even a sata raid setup or ide raid.

Any ideas??

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## Helena

 *RaceTM wrote:*   

> heya,
> 
> I've been scouring the forums for a while looking for a concrete answer to this question, but every related thread I've seen has been inconclusive so I'm hoping someone can help me out.  Right now, on my Windows box, I have two sata drives in raid 0 running windows, and two ata133 drives running in raid 1 storing my important data.  All drives are running off of a Promise fasttrak TX2plus raid adapter.  Now this setup is perfect for me, asi it meets my needs and gives me  all the space I need.  I've been looking for a way to get windows 2000 and Gentoo to dual boot off this setup, and be able to keep the sae configuration (windows and linux booting off the sata drives, but being able to access the ata drives from both operating systems).  Most of the threads I have read indicate that at this time it's not possible to run gentoo on sata drives in raid, but some people seem to claim success.
> 
> What I'd like to know is wheteher or not it would be possible to get gentoo installed on this configuration, and if so, how?  Somebody mentioned putting a regular ata drive in their system and placing the boot partition on it..but I don't recall the details, or if it was even a sata raid setup or ide raid.
> ...

 I think it is very well possible. One method would be the following. Create logical drives for Gentoo:1. a small /boot partition

2. a sufficiently large / partitionBoth have to be created on a drive that the kernel you will be using is able to recognize, but not necessarily the first in your system. So I think a separate ATA drive would be excellent for a start.

Now use a LiveCD or any other method to install Gentoo onto these 2 logical drives, using GRIB as the Gentoo boot manager. I assume you know how to do that.

Now comes the tricky part. How to boot from the newly created /boot -partition? There are at least 2 ways that I have successfully applied.

The first is using a third-party bootmanager such as Powerquest's BootMagic.

The second method is very elegant, in a way: use Windows XP's built-in boot menu. This method involves copying the first record of /boot to the Windows XP system drive and modifying boot.ini. I can show you the steps later.

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## RaceTM

hmm thanks for the reply.  I'm not totally clear on what you mean though.  From what I understand, you're suggestion to run linux totally off of a separate ata drive?  Cause preferably i'd like to get linux installed onto my sata array.  Having a boot partition on a separate drive is fine..but I really don't want to physically install and run linux on that separate drive.

Would there maybe be a way of installing on an ata drive like you said, compiling the kernel with sata and raid support, then putting that new kernel on the boot partition, moving the / partition to the sata drives, and getitng the boot partition to point to it?

 :Shocked: 

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## Papapishu

I'm currently trying to install Gentoo on a system that uses the Promise FastTrak raid system, and I'm out of luck.

I have used it's built-in system to make a stripe volume out of two harddrives, one 80GB and one 120GB.

The BIOS system tells me that it's OK, and when I boot from the LiveCD (using the boot parameters "gento doataraid"), it recognizes it and loads the ataraid module.

However, I don't get any /dev/ataraid directory, and dmesg tells me that "Promise Fasttrak(tm)  Softwareraid driver 0.03beta: No raid array found"

I've been searching just about everywhere, and found some debian forums where they suggested I make the nodes myself in /dev/ataraid but the nodes I made doesnt\ function either.

This means I can't partition the drives, and thus I can't install the system.

I don't understand, the exact problem is so common, it seams, that a solution should have appeared by now.

The debianists say that their recent system fixes this problem, and I'd like to know how...

I'd need some help, if anyone could...?

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## Helena

Well, Promise RAID and 2.6 kernel Linux are not a successful combination yet I'm afraid... There are several threads in the forum on this.

The problem seems to be that PROMISE controllers built in into the motherboard are neither full hardware not full software RAID solutions. Full hardware RAID would mean that no O/S would actually see more than 1 disk, so installation would be just like on a single (serial) ATA hard disk. On the other hand, full software RAID would mean you have 2 or more (serial) ATA disks connected and recognized by the BIOS as such and let the O/S make a RAID array out of it.

The PROMISE ASIC solutions like the PCD202xx and PDC203xx chips make life more difficult in this respect because they always require a driver, which doesn't exist for Linux 2.6 kernels yet.

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## Helena

 *RaceTM wrote:*   

> hmm thanks for the reply.  I'm not totally clear on what you mean though.  From what I understand, you're suggestion to run linux totally off of a separate ata drive?  Cause preferably i'd like to get linux installed onto my sata array.  Having a boot partition on a separate drive is fine..but I really don't want to physically install and run linux on that separate drive.
> 
> Would there maybe be a way of installing on an ata drive like you said, compiling the kernel with sata and raid support, then putting that new kernel on the boot partition, moving the / partition to the sata drives, and getitng the boot partition to point to it?
> 
> 

 As implied by y previous post... No, i.e. not yet. The problem is that you need a kernel driver that can access the boot disk, which to my knowledge has not been written yet. You may also want to check out other threads, e.g. https://forums.gentoo.org/viewtopic.php?t=99108

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## Helena

 *Papapishu wrote:*   

> I'm currently trying to install Gentoo on a system that uses the Promise FastTrak raid system, and I'm out of luck.
> 
> I have used it's built-in system to make a stripe volume out of two harddrives, one 80GB and one 120GB.
> 
> The BIOS system tells me that it's OK, and when I boot from the LiveCD (using the boot parameters "gento doataraid"), it recognizes it and loads the ataraid module.
> ...

 If Gentoo is the only O/S on your system I would say: skip the PROMISE chip, and let Linux build the RAID setup. I'm told it can be done using "drivemapper" but I have no experience with it.

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## Papapishu

I can't skip the chip, because it's a Primergy RX100 server from Fujitsu and I don't want to mess with the hardware.

I've found this: http://www.promise.com/support/file/driver/4_ftsrc-b25.tgz which is a semi-source all-linux driver afaI understand.

I'm gonna see if I can compile it and if it works.

I've heard of other 3rd party drivers too, but haven't found any sourcecode...

(Also, I'm on the 2.4 kernel)

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## tuxwatcher

I'm not sure if it will help but I have a suggestion.  I was haveing trouble trying to get a new Intel SCSI raid controller to load, because the drivers on the livecd (megaraid) wouldn't detect it.  I downloaded the new 2004.0 livecd and I am compiling the 2.6.3-r1 kernel to the RAID5.  I hope it has some better drivers for the FastTrack because I have to load one of those next week in a RAID1. Good luck!

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## Insanity5902

I am going to try that out on my nforce2 sata raid0 when this weekend.  I am downloading the stage 2 install right now.

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## RaceTM

 *Helena wrote:*   

> Well, Promise RAID and 2.6 kernel Linux are not a successful combination yet I'm afraid... There are several threads in the forum on this.
> 
> The problem seems to be that PROMISE controllers built in into the motherboard are neither full hardware not full software RAID solutions. Full hardware RAID would mean that no O/S would actually see more than 1 disk, so installation would be just like on a single (serial) ATA hard disk. On the other hand, full software RAID would mean you have 2 or more (serial) ATA disks connected and recognized by the BIOS as such and let the O/S make a RAID array out of it.
> 
> The PROMISE ASIC solutions like the PCD202xx and PDC203xx chips make life more difficult in this respect because they always require a driver, which doesn't exist for Linux 2.6 kernels yet.

 

From what I know, the TX2plus is a full software raid card..however the arrays are detected and somewhat managed by the card's bios.  So technically there should be a way to get both oeprating systems to either see the array, or build similar arrays and treat them as though they were the same...shoudln't there?

or am I way off

 :Very Happy: 

Thanks for the link btw..i'll see if I can get some more info on that Promise driver..it looks promising except for the bug reports on it

 :Very Happy: 

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## Papapishu

We ended up installing FreeBSD on it instead.

The OS wasn't a concern as long as it's secure, since it's not gonna be used frequently.

Also FreeBSD have Ports, so it's the next best thing.

It also had working support for the Promise chip.

I'm a bit disappointed though, cause my craving for optimized compilation screamed like a tortured hog when I had to install a precompiled system.

Yaaargh!!!  :Wink: 

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## Helena

 *RaceTM wrote:*   

>  *Helena wrote:*   Well, Promise RAID and 2.6 kernel Linux are not a successful combination yet I'm afraid... There are several threads in the forum on this.
> 
> The problem seems to be that PROMISE controllers built in into the motherboard are neither full hardware not full software RAID solutions. Full hardware RAID would mean that no O/S would actually see more than 1 disk, so installation would be just like on a single (serial) ATA hard disk. On the other hand, full software RAID would mean you have 2 or more (serial) ATA disks connected and recognized by the BIOS as such and let the O/S make a RAID array out of it.
> 
> The PROMISE ASIC solutions like the PCD202xx and PDC203xx chips make life more difficult in this respect because they always require a driver, which doesn't exist for Linux 2.6 kernels yet. 
> ...

 Well my guess is (I don't have the TX2 myself) that the problem will be that Linux will still see both drives, as would Windows if installed without a Promise driver. You're exactly right in saying "somewhat managed"... You'll see when examining the kernel startup log with

```
dmesg|more
```

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## Crg

 *Helena wrote:*   

> The problem seems to be that PROMISE controllers built in into the motherboard are neither full hardware not full software RAID solutions. Full hardware RAID would mean that no O/S would actually see more than 1 disk, so installation would be just like on a single (serial) ATA hard disk. On the other hand, full software RAID would mean you have 2 or more (serial) ATA disks connected and recognized by the BIOS as such and let the O/S make a RAID array out of it.

 

As explained in detail to you in many threads the promise fasttrack controller is full software RAID. 

[*] I have shown you code

[*] I have pointed out what it says in configuration of the kernel

[*] I have even in private given you many links about it and offered to walk you through line by line the kernel drive code.

As you say with software you will see both drives and if you bothered to check your dmesg output you'd notice all your IDE devices listed there.

Spreading misinformation on this forums about this controller when you have been corrected many times is not helpful to others.  It could be other people's data you put at risk.

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## RaceTM

So then what does all this mean?

Promise apparantly has drivers for the controller card I have.  If I install these drivers, does it mean that

a) my drives will be recognized, but my array will have to be rebuilt and will only be usable by linux

or b) the drives and arrays will be recognized and I will have full access to all partitions from my windows and linux opeerating systems?

It seems that similar to the dozens of other threads I've read on this topic, I'm getting mixed information  :Sad: 

Any clarification would be great.  thanks for the replies so far!

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## Crg

 *RaceTM wrote:*   

> Promise apparantly has drivers for the controller card I have.  If I install these drivers, does it mean that
> 
> a) my drives will be recognized, but my array will have to be rebuilt and will only be usable by linux
> 
> 

 

If you managed to use the drivers from promise both your disks will be accessed the same from windows and linux, as the information written to the first part of the disk by the bios instructs the driver (in both windows and linux) on how to configure the disks.

The promise driver was closed source and hense not an option for me as I tend to run very custom kernels, I'm not sure what success if any, anyone has had with their driver.

The ataraid driver is open source but has limited support and not available in 2.6, I started to hack this driver some while ago to make it more complete but chucked my source out as don't want to help support this type of hardware - it's just a ide controller, and as you can see it causes a lot of confusion.

With 2.6 they are talking about creating a util that will be able to configure another linux software raid solution with the information read from the first part of the disks.  Not sure how far they have got with this as I don't pay much attention to it's development.

The best posts to read about or person to ask about ataraid on this forum is probably taskara.

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## RaceTM

hmm that's good news.  :Smile: 

Would you happen to know where I can find some more information on getting the promise driver loaded at boot and loaded into the kernel, so that I can install my linux system and boot it off the array?  I'm comfortable with recompiling a kernel with the embedded kernel drivers, modules, etc, but i haven't dealt with third party drivers before..especially with loading that at boot.

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## taskara

Hey RaceTM,

got your PM.

Ok here are my thoughts on the situation:

AFAIK Promise to NOT make ANY raid controllers that are full hardware driven. They all require a driver, and ESPECIALLY the cheap ide raid controllers.

I have a tx2, and it is not hardware raid.

The Linux kernel will natively support this controller as an ide controller (so you can access both drives seperately), but if you want it to access as a raid controller things are different.

firstly, as Helena mentioned, forget 2.6 kernels.

the ataraid driver is an ugly 2.4 hack, so at the moment you will need to stick to 2.4.x

secondly, because you are using a 20278 card, some 2.4 kernels may already support this is raid function - ie ck-sources.

Promise have not released a driver for 202x cards, only 203x sata cards - so that's not going to help you.

IF you can get a raid driver installed, then you will see /dev/ataraid as the raid device.

you just fdisk the device and make partitions etc as a normal hdd - and you should also see your windows partitions on it.

The problem is that you need to get the driver working. I don't think any gentoo livecds (since 1.2) really work properly with ataraid, so my suggestion to you would be to boot to knoppix and see if it detects the raid array, or better still - install a non-raid disk into your system and build a stage3 system quickly and then fiddle with kernels and drivers until you can get the raid array working - then use the install from the normal disk to access and install gentoo onto the raid array.

You will prob need the latest experimental version of grub - also you should install grub to a floppy disk, and boot to it then install teh bootloader.

check out this thread - https://forums.gentoo.org/viewtopic.php?t=7460

if you can get a driver installed and working, then you should not have a problem dual booting.

hope this helps

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## RaceTM

hmm lots of good info

thanks for the help, i'll give it a shot and see what I can come up with!

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## 1eyedhive

I have an odd setup.

I started out with an onboard fasttrack133 raid1 controller, the ugly 2.4 hackjob under red hat 8.

then i got another drive and went to a s/w raid5 (2 80's and a 120 with ~40GB left over for system crap), first RH8, now gentoo with a 4th drive.

the current setup:

2 WD 80GB HD's

1 WD 120GB HD

1 WD 200GB HD

2 Promise ata100 controller cards

Software RAID

the former gentoo raidtab file:

```
raiddev             /dev/md0

raid-level                  5

nr-raid-disks               4

chunk-size                  64k

persistent-superblock       1

nr-spare-disks              0

    device          /dev/hdb2

    raid-disk     0

    device          /dev/hdc1

    raid-disk     1

    device          /dev/hde1

    raid-disk     2

    device          /dev/hdg1

    raid-disk     3

```

in any case, it runs beautifully, even on a p2 350. no hardware controllers whatsoever.

now going from doze to gentoo and trying to dual boot them and you're asking for trouble, even with a 'hardware-assisted' raid array, find a cheap P2 or P3 (ebay is your friend), put some ata100 cards in it and away you go.

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## RaceTM

well I booted up with knoppix, and there was a /dev/ataraid directory..as well as a /dev/scsi directory.

Only problem is that there were dozens of listings in there and they all have a locked icon over them.  Is there any way to find out what the arrays would appear as (keeping in mind one drive is a sata array :/ )?

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## taskara

if knoppix has detected and loaded a raid driver, then it should appear as /dev/ataraid/disc0/disc

or something like that

if it has not, then it will detect them individually as either/dev/hde

or /dev/sda

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