Raid on Rackmount cases?

[Carlos Moreno]

Hi,

I have zero actual experience setting up rackmount machines,
and in particular I'm puzzled about how this will work when
we want to set up a machine with RAID.

I know that many motherboards have on-board RAID support,
but most of what I've seen offers only RAID 0 and RAID 1,
and not RAID0+1 or RAID 5.

But when I check, say, Promise for better SATA RAID cards,
all of them are cards that fit perpendicularly to the MB on
an PCI slot -- my impression is that they would not fit on
a rackmount case (not in a 1U or 2U, I'm guessing).

What's the typical approach here? Is it that I'm looking
only at low-end RAID systems and low-end motherboards?
Or is it that if we want a truly powerful server with a
good RAID setup we have to go to the full-size 4U?

Thanks for any advice or pointers!

Carlos
--

 

[Rod Speed]

I have zero actual experience setting up rackmount
machines, and in particular I'm puzzled about how this
will work when we want to set up a machine with RAID.

I know that many motherboards have on-board RAID
support, but most of what I've seen offers only RAID 0
and RAID 1, and not RAID0+1 or RAID 5.

Yep, because thats what the chipset used supports.

But when I check, say, Promise for better SATA RAID
cards, all of them are cards that fit perpendicularly to the
MB on an PCI slot -- my impression is that they would not
fit on a rackmount case (not in a 1U or 2U, I'm guessing).

What's the typical approach here?

Go SCSI.

Is it that I'm looking only at low-end RAID
systems and low-end motherboards?

Yep, IDE RAID doesnt have as many
choice available as with SCSI RAID.

Or is it that if we want a truly powerful server with a
good RAID setup we have to go to the full-size 4U?
Yep.

Thanks for any advice or pointers!

You shouldnt have an exclamation mark there |-)

 

[Rita_A_Berkowitz]

Hi,

I have zero actual experience setting up rackmount machines,
and in particular I'm puzzled about how this will work when
we want to set up a machine with RAID.


Great.



I know that many motherboards have on-board RAID support,
but most of what I've seen offers only RAID 0 and RAID 1,
and not RAID0+1 or RAID 5.

Onboard RAID is a total waste. You're better off using a separate
controller that best suites your needs.

But when I check, say, Promise for better SATA RAID cards,
all of them are cards that fit perpendicularly to the MB on
an PCI slot -- my impression is that they would not fit on
a rackmount case (not in a 1U or 2U, I'm guessing).

Your only true solution is a good SCSI RAID solution.

What's the typical approach here? Is it that I'm looking
only at low-end RAID systems and low-end motherboards?
Or is it that if we want a truly powerful server with a
good RAID setup we have to go to the full-size 4U?

Depends on the your needs. With 73 GB Cheetahs being dirt cheap you shouldn
't have too much trouble filling a 4U cabinet with 14 drives.

Thanks for any advice or pointers!

Any time.



Rita

 

[Marc de Vries]

Hi,

I have zero actual experience setting up rackmount machines,
and in particular I'm puzzled about how this will work when
we want to set up a machine with RAID.

I know that many motherboards have on-board RAID support,
but most of what I've seen offers only RAID 0 and RAID 1,
and not RAID0+1 or RAID 5.

You can defintately find solutions with onboard Raid 0, 1 AND 0+1

I have seen several boards from Tyan with IDE controllers with that
functionality. That is probably the easiest and cheapest solution.

There also seem to be onboard Raid5 solutions for SCSI. (have never
seen them for IDE)
Tyan has some boards with zero channel raid scsi. From what I just
read there and on the adaptec site, it seems like you can have raid5
with that. It might also use a pci slot, but I'm not sure about that.
You might want to contact Tyan (or another producer of server boards)
about that.

But when I check, say, Promise for better SATA RAID cards,
all of them are cards that fit perpendicularly to the MB on
an PCI slot -- my impression is that they would not fit on
a rackmount case (not in a 1U or 2U, I'm guessing).

That is why 1U and 2U cases have mobo's with PCI riser cards.
You can get a idea of what those look like at this url:
ftp://ftp.tyan.com/matrix/matrix_riser.pdf

This way standard PCI cards can be installed parallel to the mobo. A
1U case will then usually accomodate 1 PCI cards.
When you buy a solution from Dell or HP or the like, you can often use
2 PCI cards in a 1 U server.

I might seem like a Tyan advertisement, but I just know that they have
a lot of server solutions, so I took their site for some examples.
I have no personal experience with Tyan.

What's the typical approach here? Is it that I'm looking
only at low-end RAID systems and low-end motherboards?

Get a mobo with a pci riser card.
Unless you opt for an onboard solution, this will give you the most
flexibility.

Or is it that if we want a truly powerful server with a
good RAID setup we have to go to the full-size 4U?

There is no reason at all to do that.

Valids reasons for using a 4U server are when:
- you need more PCI slots
- you need more room for harddisks in the case. Can't install all that
many hotswap bays in a 1U server.

Of course you will probably have more options to choose from if you
use a 4U server. It might even be a cheaper solution for you.

Marc