Topic: ATA-RAID support

[Willy Roesen]

I need a 'Howto':
There is no support for ATA RAID in kernel 2.2.19
For obvious reasons, hardware RAID is preferable to Software RAID.
A howto describing the implementation of drivers for various ATA RAID cards (3Ware, Promise, Adaptec) on a Start-/Installation-diskette would come in handy, since the install CD just breaks off and restarts the machine instead of asking for driver supplements.
I for one do not have the basic Linux knowledge to fend for myself in that respect.
Maybe there are others with the same problem ?

[Kelvin]

If you did a search of the forums, you will find that there has been numerous discussions and even mini howtos on this.

Eg. the highpoint based RAID controllers.

Kelvin

[Charlie Brady]

Willy Roesen wrote:

> There is no support for ATA RAID in kernel 2.2.19

There is added support for 3ware raid, but that is probably hard to come by these days, unfortunately.

> For obvious reasons, hardware RAID is preferable to Software
> RAID.

Are the reasons obvious? Unless you need hot-swap drives or extreme speed, I'd recommend that you use the built in software RAID.

Charlie

[Rob Walker]

Hrmmm....

I have a customer who needs RAID 5, to move their files to a
fileserver, as well as having a central repository for
backups.  We tested out the esmith server at our site without
RAID, but thought that it was a standard redhat kernel which
was being used.

I _have_ looked at the archives, and they mention some
required compiling, but not much else (like where to get
the .o files, how to convince the esmith 5.5 installer to
load up different modules at install (does the Ctrl-X do the
trick?)).

Am I going to be installing esmith 5.1, or 5.6?  Is it possible
that I can get 5.5 working somehow?

tia,
rob

[Rob Walker]

And, of course, since I am a complete idiot, I forgot to
mention that the specified controller is a 3ware 7500-4.

thx,
rob

[Willy Roesen]

Please run that by me again.
There is added support for 3ware RAID ?
In the SME Server 5.5 ?
Please verify !!!!!!

If that is indeed the case, then I'm a happy man, even though I've just
spent another good couple of hundred dollars for an alternate solution.
Btw. 3ware products can indeed be found in Denmark !

I certainly prefer hardware RAID, not just for the hotswap facility,
but also because of the much simpler procedure in case of a drive
breakdown.

> I'd recommend that you use the built in software RAID.

That, to be sure, has worked beautifully for me in about a year and a
half now, but then again, I have yet to experience a drive breakdown !
(knock on wood).

Regards

[prostar]

Could somebody confirm the latest status on support for the 3ware family of RAID cards?

I will have to move to a new disk array within a month (using e-smith server 5.1.2, although thinking about upgrading to 5.5) and I'm sure to go for hardware RAID 5.

The possible solutions for me seems to be the Adaptec 2400A (my first choice) or the 3ware 7500-4.

Could anyone help me out on this?

[Willy Roesen]

Kelvin wrote:
>
> If you did a search of the forums, you will find that there
> has been numerous discussions and even mini howtos on this.
>
Oh, really ?
My search revealed nothing, but perhaps I used incorrect search parameters ?
Seeing the other answers below raises even more qustions.
I should like a glimpse of the said howto for myself.
Where to find ?
> Eg. the highpoint based RAID controllers.
>
I've never heard of highpoint based RAID controllers ?
>
> Kelvin

Wyron

[Willy Roesen]

Rob Walker wrote:
>
> And, of course, since I am a complete idiot, I forgot to
> mention that the specified controller is a 3ware 7500-4.
>
Ah, my friend - there you go.
As you can se from other posts on this subject the support for ATA RAID isn't that obvious.
The 7500-4 would have been my first choice also if not for the pricing. I thought I could cut corners with a Promise card - silly me.
> thx,
> rob
I have already ordered a hardware RAID1-solution from Darrell May (http://myezserver.com/), but would of course in the long run prefer a RAID5-solution (like the 3ware 7500-4 offers).
Lets hope for help from someone with insight into the deeper corners of the SME Server - and first of all keep this thread alive so we can perhaps nag Mitel for a patch in the next release.

Regards
wyron

[Kelvin]

Hi Willy,

> My search revealed nothing

Search for "Highpoint" and remember to set the All Dates setting and you'll get pages.

> I've never heard of highpoint based RAID controllers ?

Really ? One example - Adaptec 1200A. At one point, I even remember seeing on Highpoint's web site that the Adaptec 2400A was also based on a Highpoint chip (though a different one to the 1200A which is based on the HPT370A), although I've never been able to confirm this.

Or, if you just want to dispense with all the hoo-hah about drivers, you could use OS independent RAID chassis solutions like the Accusys systems (they have RAID-1 as well as RAID-5 versions). They are hot-swap capable with built-in drive failure alarms and automatic rebuild. The downside is performance as the chassis connects to the motherboard via a single cable / channel and appears to the motherboard as one hard disk. Multi-channel RAID cards can / (must in ATA RAID cards) distribute the hard disks over the different channels and thus can independently read / write over the different channels. Some of us even use the RAID-1 versions as a form of backing up a system (with some caveats).

Kelvin

[Willy Roesen]

Kelvin wrote:
>
> Hi Willy,
>
> Search for "Highpoint" and remember to set the All Dates
> setting and you'll get pages.
>
Ah, I see - this search certainly revealed some items.
Sadly enough, they didn't shed much 'light on my plight', if you'll pardon the phrase.
>
>
> Kelvin
>
What I need (and others, seemingly) is a thorough howto, starting at the point where I have a driver-.rpm available for whatever ATA RAID-card I have bought in my stupidity, not checking the compatibility beforehand.
I for one should have ben very pleased, if there had indeed been substance behind the hint that the 3-ware 7500-4 card was supported. Then at least I should have had something definite to aim for.

regards
wyron

[Michael]

I, for one, would be very grateful if someone can point me where to get a 3-ware card in the UK.. Why hardware ? I am assuming....probably wrong here that if the entire motherboard and processor dies, I can transplant the raid card  and disks into an entirely new machine, run SME 5.5 CD, and all will be fine.

NB
One thing that keeps coming to mind reading these posts is an entirely different attitude to mine about SME and Linux in general. There IS a major problem with Linux......
 
I built a server using RAID 5 28 months ago. From scratch. I used Mandrake..as it happens. It has performed faultlessly...all new bits, scsi disks etc.

Now I have a disk crash.

Since Linux has worked so faultlessly I have not used a command line for 28 months.
I am totally lost. Thats the problem. If you agree its a problem

Hence the beauty of SME server. All I would have had to do is rebuild using a completely standard CD.
No fiddling at all.

Raid 1 in hardware, with NO intervention at all when installing is the way to go...
Never mind the cost of disks.

Tia
Michael

[Charlie Brady]

Michael wrote:

> I am
> assuming....probably wrong here that if the entire
> motherboard and processor dies, I can transplant the raid
> card  and disks into an entirely new machine, run SME 5.5 CD,
> and all will be fine.

I'd expect that to work.

OTOH, if your raid card dies, you are SOL. That is the main reason why I recommend linux software RAID unless you have particular reasons to do otherwise. A pair of linux software RAID drives should be usable with any motherboard.

Charlie

[Michael]

Thanks Charlie...yes..so long as the motherboard can recognise the disks(my older boards struggle with 120MB)...and has IDE ports...will new ones have them in say 3 yrs time ?

[Kelvin]

Charlie Brady wrote :

> OTOH, if your raid card dies, you are SOL.

That is not universally true. It *might* be true of RAID 5 cards (never had the misfortune of needing to see if it is or not). But it certainly is not true of the RAID 1 cards I've worked with (no, the card did not die, I was troubleshooting a problem and replaced the RAID card with another similar card to eliminate it as a possible culprit).

Kelvin