# Real Hardware RAID

## Limit

Good day to all.

I need а ATA RAID controller for gentoo-2.6.8-r3. It must be a real hardware RAID. I have about 500$. What can I buy for this money?

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## 2K_amd64

I`ve bought 2 Highpoint RocketRAID 1820 for that situation. it has 8 sata channels, hw raid, lets you do raid10. price is 450 USD in Turkey. It has drivers for amd64 too, with source codes.

BUT

as I posted, I didn`t have any trouble on tyan s2886 dual opteron, I`m down on Intel motherboards with that card/driver.

I`d/I`ll not buy any special hardware anymore, if I can`t see it on "make menuconfig".

Highpoint RocketRAID works fine, if you can get it working.

Recomendation : Buy something what has native kernel support. 

There is a nice howto or doc as far as I remember on sata raids (pointing which one is  hardware and which one is not). Consider browsing www.tldp.org or google around for that document.

2K

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## 2K_amd64

with a special adapter, you can use standart IDE disks in SATA raid arrays

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## Limit

Thanks alot! I foget to say that I need RAID0, sorry.

My system are based on KT266A Chaintech 7VJDA   :Very Happy:   and I need RAID0 ATA controller. RAID 10 is cood, but I have no need in such abilities.

What else can you advice?

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## drescherjm

I do not know of a single raid controller that does not have raid 0 so you can buy that one provided there is a linux driver.

[EDIT]

Oh.. I see he said there was a driver..

[/EDIT]

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## drescherjm

 *Quote:*   

> What else can you advice?

 

My question is why do you need hardware raid? To dual boot to windows? For performnce? The difference in performance between hardware raid0 and software is marginal at best. You will probably be spending more for the raid card than your pc is worth and will be much better served by a faster pc.

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## Limit

 *drescherjm wrote:*   

>  *Quote:*   What else can you advice? 
> 
> My question is why do you need hardware raid? To dual boot to windows? For performnce? The difference in performance between hardware raid0 and software is marginal at best. You will probably be spending more for the raid card than your pc is worth and will be much better served by a faster pc.

 

I already have software-raid (using device-mapper), but speed of work with disks not enought, especially with 50-70 smb-connections. I think that this problem can be solve using real hardware RAID controller. Can you help me to choose it?

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## drescherjm

I asked that because there is very little if any performance advantage going from software raid 0 to hardware raid 0 because there is very little cpu time spent to stripe the data. In fact a hardware raid 0 controller may actually be slower than software raid 0 because the cpu on the card will most likely be significantly slower then the main cpu.

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## Limit

I have two raid massive working on my copmuter. At the same time there are about 50 samba and 40 ftp connected clients. Moreover then working samba and ftp there are some different resources consumption programms. CPU 1700XP is not able to solve all tasks correctly. In last year I used Promise FastTrak100TX2 with kernel-2.4. and it worked excellent! In 2.6 that controller don't support like hardware raid, only like simple IDE-controller (or I simply don't now how to make it work in RAID-mode!) Thats why I decide to buy hardware raid. You are right that good processor better than raid-card, but I'll plane to change this computer in future, but not now. Please, help me to chose ATA RAID for 2.6.8-r3! 

P.S Sorry my english =)

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## drescherjm

FastTrak100TX2 is a software RAID solution. The card boots with a special bios and special raid driver that uses your cpu to do the raid. I gaurantee that the builtin linux software raid is at least as fast as the FastTrak100TX2 and you can use any regular ATA controller.

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## jschellhaass

If you need hardware RAID I would recommend a 3ware controller.  True hardware RAID, works great under linux.  Supports RAID 0,1,5 and 10.

jeff

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## Limit

 *jschellhaass wrote:*   

> If you need hardware RAID I would recommend a 3ware controller.  True hardware RAID, works great under linux.  Supports RAID 0,1,5 and 10.
> 
> jeff

 

I'll be thanks to you, if you'll advice me what model will work with 2.6.8 like real hardware RAID?

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## jschellhaass

What are you looking for?  ATA or SATA?  Howmany ports?  They make a 4, 8 or 12 port controller in each type.  I see they still also still have a 2 port controller that does RAID 0 or 1.

jeff

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## Limit

 *jschellhaass wrote:*   

> What are you looking for?  ATA or SATA?  Howmany ports?  They make a 4, 8 or 12 port controller in each type.  I see they still also still have a 2 port controller that does RAID 0 or 1.
> 
> jeff

 

I'm looking for ATA RAID0/5/10 controller with 4 or 6 ports.

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## jschellhaass

Then you will want the 7506-4LP (Low Profile) or 7506-8.

jeff

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## Limit

Thank you very much jeff! It's that thing what i'm looking for!

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## localghost

 *drescherjm wrote:*   

> I asked that because there is very little if any performance advantage going from software raid 0 to hardware raid 0 because there is very little cpu time spent to stripe the data. In fact a hardware raid 0 controller may actually be slower than software raid 0 because the cpu on the card will most likely be significantly slower then the main cpu.

 

I have this:

```
0000:00:08.0 RAID bus controller: Promise Technology, Inc. PDC20378 (FastTrak 378/SATA 378) (rev 02) 
```

In the BIOS the two SATA's are defined as RAID0, and that other OS sees them as one drive. But in my Gentoo Graphical Pre-installation Environment (aka Knoppix 3.7) I see two drives, not one. See this thread for further details: https://forums.gentoo.org/viewtopic.php?p=2061938

My conclusion after reading your post, is that the BIOS setting about hardware raid is irrelevant for Linux, and that I should use software raid no matter what. Can someone please confirm/deny this?

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## cyrillic

 *localghost wrote:*   

> I have this:
> 
> ```
> 0000:00:08.0 RAID bus controller: Promise Technology, Inc. PDC20378 (FastTrak 378/SATA 378) (rev 02) 
> ```
> ...

 

That is because you have loaded the software RAID driver provided by Promise for that other OS.

 *localghost wrote:*   

> My conclusion after reading your post, is that the BIOS setting about hardware raid is irrelevant for Linux 

 

This is mostly true, but the BIOS settings will affect the way the bootloader works (or doesn't work).

 *localghost wrote:*   

> and that I should use software raid no matter what. Can someone please confirm/deny this?

 

For a Linux only installation, yes.

For a dual-boot installation, you will have difficulty because the Linux software RAID drivers are not compatible with the Windows software RAID drivers (different array formats).

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## Galahad

BIOS setting doesn't matter for controllers that don't do real hardware raid, meaning all the cheap ones.

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## silentplummet

Also consider that with a PCI RAID card (or cards) your I/O bandwidth is limited to that of the shared PCI bus.  Theoretically you can get 66 MHz (66 mbit/s) out of that, but you can go ahead and subtract network, PCI sound, PCI video, etc....

Overclocking the PCI bus is rarely an option.  You can pay lots of money to get a pci-e chipset which is faster but I've never personally seen one so I assume it's very rare.

I found a much more acceptable, cheaper, and faster solution is to software RAID-0 over two ATA-133 IDE channels and two SATA channels on the FSB frequency.  This probably results in a bandwidth limitation higher than my four drives could ever match.

Edit:  note that this solution also provides better redundancy in RAID-5 and RAID-1 modes because arrays are shared across different physical devices and channels.  If your single PCI card bites the dust, that means all your drives are simultaneously going down.  Not an option in a production environment.

The only reason to get a PCI solution these days is for a battery-backed write cache.  But that too is becoming irrelevant with the growing prevalence of UPS systems.

Edit 2:  If you're desperate for a hardware solution, the only real option you have is to get a hardware unit which is external to the computer.  They make great networked and firewire arrays by which you can avoid the bandwidth problems of the PCI bus and get real features like physical hardware security (lock + key), and avoiding all the dangers of having some stupid WinXP or Gentoo box go down and take your whole office down with it.

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## Limit

Good day to all. I'm very thank you for your advices.

Now I'm have a new idea: what about external storage?

It must:

1)Connect via 1Gb ethernet

2)SATA/SATA 2 disks

3) ~ 1500$ without disks

I know that better solution will be storage with SCSI+FiberChannel but it's cost too much for me.

And at last, what new RAID-card do you use/or can recomend to use?

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## jsnorman

 *jschellhaass wrote:*   

> If you need hardware RAID I would recommend a 3ware controller.  True hardware RAID, works great under linux.  Supports RAID 0,1,5 and 10.
> 
> jeff

 

Absolutely.  3ware for the price cannot be beat for true hardware raid.  It has an XOR hardware engine, custom open source GPL linux kernel code supporting most of their adapters, great sata support, inexpensive, redundant power options, etc.  

As someone else said, promise is not true hardware raid either.  I am not sure about highpoint.

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## Limit

And what about external storage? Does anyone can help ?

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## jschellhaass

I think you will problems meeting that price point.  Coraid (http://www.coraid.com) has a 4 disk unit for $2k.  These systems use ATA over ethernet.

jeff

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## schwicky

 *Limit wrote:*   

> 
> 
> 2)SATA/SATA 2 disks

 

If you're having troubles with 50-70 smb connections you should really think about using more than just 2 disks because your disks will spend more time to position the read and write heads than transfering data. Moreover if all the connections are concurrent.

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## Jerry Gardner

Take a look at the Netcell SR5103. It's a true hardware RAID controller that supports 5 SATA drives in RAID 0, 1, XL, and JBOD. Costs about $250.

To the OS this board looks like a single IDE drive, so no special RAID drivers are needed.

http://www.netcell.com/_personal/products.html

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## Limit

 *schwicky wrote:*   

>  *Limit wrote:*   
> 
> 2)SATA/SATA 2 disks 
> 
> If you're having troubles with 50-70 smb connections you should really think about using more than just 2 disks because your disks will spend more time to position the read and write heads than transfering data. Moreover if all the conections are concurrent.

 

Ow, sorry, it's better say SATA/SATA II disks. Of course i'm going to use 5-7 disks =)

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## Limit

Hi all!

I change my moherboard, and it has a PCI-E now. And now i'm looking a real hardware-RAID controller (PCI-E, SATA, 6 or 8 disks, RAID 0, 1, 5, 6, 1+0 (10)). I find "Promise Technology SuperTrak EX8350 8-Port SATA PCI-E RAID Controller" but main problem that it's a PROMISE =) and i'm not sure that it is a real hardware controller. 

Using 2.6.10 kernel. 

And what about PCI-E devices in linux? How does it works (especially i/o controllers).

Can somebody help me?

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## Limit

I'm find what i want. It is Areca ARC-1220 (8x SATA300 RAID PCI-E x :Cool:  128MB. And alos i'm find some answers for the main theme of this topic: what is a real hardware raid controller?

http://www.clintoneast.com/articles/linux-sata-raid.php

I'll post there my impression about this card soon.[/url]

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## Spockmeat

Interesting, I just saw two other reviews giving the Areca cards very good reviews.

http://www.tomshardware.com/storage/20051031/index.html

http://www.tweakers.net/reviews/557/1

Do post how well you like the card. I'm somewhat shopping around for a real hardware raid card myself (currently running 2 drives in software with windows and linux on them... pain in the butt to set up and has a higer cpu usage than I'd like).

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