Another RAID for Beginners Question

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Philadelphia Frank

I have an Asus A7N8X Deluxe and two Maxtor 160GB IDE drives I would
like to hook up as a RAID. I have a few general questions I hope
someone can clear up for me. I'm looking for speed not protection. I
think I want stripes rather than a mirror.

Does the A7N8X Deluxe provide the ability to connect the Maxtor EIDE
drives as RAID? The manual seems to be talking about Serial ATA drives
mostly.

I also have a Belkin Ultra 133 card that appears to provide RAID
support. I bought the card because I needed more connections for more
than 4 drives. The card has a Silicon Image Sil 0680 Medley chip that
I believe is the RAID controller. ( I suspect my terminology is not
correct).

Assuming the ma inboard does provide RAID support, which way should I
go? Should I use the dedicated card with the Sil 0680 or the Asus
board? I still might want to use more that 4 IDE slots so I probably
will be needing the card either way.

Do I have a choice when it comes to where to hook up the cables?
Should both drives connect to one IDE port and share the same cable or
should I hook up each drive to it's own port and have it's own cable?

How well do drive imaging programs (Ghost, Drive Image, etc) deal with
RAID setups? I vaguely remember a magazine article, MaximumPC, that
said only one version of Power Quest's Drive Image would work with a
RAID. Does anyone have experience with that?

How about installing Windows XP onto a fresh new RAID setup - can a
beginner pull it off? I know there is a screen that appears prompting
the user to provide drivers for RAID during the installation. What
happens next? Does the RAID configuration take place within the
controller chipset and XP sees the two drives as one, or does Windows
make the two disks one?

I'll be reading more about RAID as I wait for answers; I don't expect
all the answers from newsgroup readers. I'm hoping you might remember
the uncertainty and vague uneasiness that comes from reading something
new. I'm hoping someone can steer me in the right direction.

Thank you for your time and help;
Frank
 
Philadelphia said:
I have an Asus A7N8X Deluxe and two Maxtor 160GB IDE drives I would
like to hook up as a RAID. I have a few general questions I hope
someone can clear up for me. I'm looking for speed not protection. I
think I want stripes rather than a mirror.

Does the A7N8X Deluxe provide the ability to connect the Maxtor EIDE
drives as RAID? The manual seems to be talking about Serial ATA drives
mostly.
Click to expand...

Reading the specification summary in the manual will give you some
ideas. There is a dual connector SATA chip and the manual says
RAID0/1, so it will do either with two SATA drives. You could use
PATA drives, if you buy PATA drive to SATA connector converters.

The Southbridge supports two PATA IDE connectors and a total of
four drive devices, like many other Southbridges of its generation.
I also have a Belkin Ultra 133 card that appears to provide RAID
support. I bought the card because I needed more connections for more
than 4 drives. The card has a Silicon Image Sil 0680 Medley chip that
I believe is the RAID controller. ( I suspect my terminology is not
correct).
http://12.24.47.40/display/2/search...chType=allwords&searchby=keywords&r=0.5601923


Assuming the ma inboard does provide RAID support, which way should I
go? Should I use the dedicated card with the Sil 0680 or the Asus
board? I still might want to use more that 4 IDE slots so I probably
will be needing the card either way.
Click to expand...

If all you own is PATA drives, use the 0680. Both chips will be
sitting on the PCI bus, so you cannot get more than 100MB/sec
anyway. The only way to get past that mark, is with something like
two SATA Raptors RAIDed on a ICH5R Southbridge (max 266MB/sec), or
use a server board with PCI busses faster than 133MB/sec, as a
faster PCI bus can let PCI RAID cards show their stuff. Of course,
the flavor of RAID has to suit the available bandwidth in any case.
Do I have a choice when it comes to where to hook up the cables?
Should both drives connect to one IDE port and share the same cable or
should I hook up each drive to it's own port and have it's own cable?
Click to expand...

With two drives, one per cable sound good.

If doing two arrays, you don't have much choice but to fill the
cables, but you don't want both drives of an array to be on the
same cable. You can lose 25% performance configured that way.
How well do drive imaging programs (Ghost, Drive Image, etc) deal with
RAID setups? I vaguely remember a magazine article, MaximumPC, that
said only one version of Power Quest's Drive Image would work with a
RAID. Does anyone have experience with that?
Click to expand...

Oh, you want software support too ? Only if Bill Gates wills it.
Like having to wait for the next MS OS to get SATA hot plugging :-(
Any hardware config that isn't "vanilla" is always a struggle.
Like, how many days did you waste before being able to burn a
DVD without problems ? Always expect trouble and extra expense
with a MS OS.
How about installing Windows XP onto a fresh new RAID setup - can a
beginner pull it off? I know there is a screen that appears prompting
the user to provide drivers for RAID during the installation. What
happens next? Does the RAID configuration take place within the
controller chipset and XP sees the two drives as one, or does Windows
make the two disks one?
Click to expand...

The RAID BIOS executes at POST, and supports the ability to write
a reserved sector with info about which drives are members of which
array. Possibly the RAID BIOS also has the INT13 services necessary
for the rest of the BIOS to support booting from the RAID. Once the
OS has booted far enough via INT13, the OS can load its driver and
I/O calls from there are OS driver supported. XP needs the driver
available "early" via F6, so it can be able to do anything with the
drives. I guess it is too much to expect, for the OS to use INT13
for the whole install.
I'll be reading more about RAID as I wait for answers; I don't expect
all the answers from newsgroup readers. I'm hoping you might remember
the uncertainty and vague uneasiness that comes from reading something
new. I'm hoping someone can steer me in the right direction.

Thank you for your time and help;
Frank
Click to expand...

The recommendations I read, suggest not using RAID for the boot disk.
It is hard enough to keep a single disk healthy, with chkdisk and the
like. Imagine not being able to boot your computer and trying to fix
the disk. A RAID makes a great scratch disk, for video editing or
some kind of rendering application. RAIDs don't necessarily make good
video capture targets, as frequently they drop frames compared to a
single IDE which doesn't drop any (driver fairness problem).

In the case of mirrored RAIDs, you should practice the procedure for
pulling a drive out of the mirror (i.e. pretend one drive has failed)
and see if you understand the process well enough to restore the RAID,
using the drive that you pulled as the replacement. The RAID BIOS
should ask you to rebuild the array, which means copying the data
from the good drive to the "replacement" drive. You don't want any
uncertainty in your mind, as to how the process works, when you have
live data on the disk, and you are freaking out when the array
suddenly announces it has a "critical" status. (Even with a mirror,
you still need to do backups, because a mirror can corrupt both
drives, if it is in a bad mood.) Less to worry about on a stripe,
because when it breaks, it is broken :-)

Used as a scratch disk, I don't have a problem with RAID. Similarly,
no problem if the RAID is a non boot disk on a server, as there
the performance gets used to serve multiple computers. Using a
RAID as the boot disk on a desktop, is a waste of mental energy
and time. How many operations on your computer require copying
GB size files ? A RAID doesn't help with a bunch of 10KB text
files. Performance there is dominated by seek time, and a Raptor
will solve that problem.

Just my opinions,
Paul
 
Wow! I am very grateful for the information you have provided. I cant
say I understand it all. That SATA and PATA is new to me. I will look
into it.

Thank you thank you thank you.

Frank
 
It appears the folks at Silicon Image are poor web designers.
I gave you this link, but it has a session cookie (the number
at the end of the link) that expires after a period of time.
So, this link is useless, and the user has to go through more
hassle as a result. In fact, I cannot display it either, to
verify that I've located the same page or not.

http://12.24.47.40/display/2/search...chType=allwords&searchby=keywords&r=0.5601923

To find info on the 0680:

http://www.siimage.com/products/sii0680.asp

Click "product support" at the bottom of the page.

This will show the web weenies that you had an interest in the
0680, so they'll make more of them at the factory or something :-)

A pane that says "Search for Articles" will show up.
Type "0680" in there and do a search.

You will be given a page of links, and that page is the one I
tried to quote in my post.

One of the pages has this comment:

"IDE/RAID: Upgrading a 680 IDE Card to RAID
If you have a 680/680A-based IDE controller board and want
RAID functionality, you cannot simply download the RAID drivers
to get RAID functionality. You must also modify the BIOS in the
card. This can be done but depends on how your board maker has
designed the card since Silicon Image does not make any cards
for the retail market. The SiI0680/0680A does support FLASH
memory BIOS as well as EPROM, but many board makers use EPROM
to save cost.

To tell if your card uses EPROM, see if there is another
smaller chip outside of the 680 controller chip. If the part
number of that smaller chip begins with 27xxx, then you have
EPROM BIOS and you cannot use the flash utility to upgrade
your BIOS. You must use an EPROM programmer tool. If you do
want to program your own BIOS, please note that the RAID BIOS
is larger than the IDE BIOS and may not fit in the EPROM provided
with your IDE card.

If your card does have a FLASH-based BIOS, then please go to
the BIOS and flash utility related articles on the lower right."

So, the chip apparently supports RAID, but I wonder if it isn't
anything other than "soft RAID", where the host processor does
all the work. I guess you are supposed to go to all the trouble
of flashing the card to make it into a RAID, to find out :-)

If you have a mirror on a controller card which is a "soft raid",
then the Windows driver sends two copies of the data down to the
device. Effectively, the controller on the card doesn't contribute
to the process. A hardware assisted RAID is sent one copy of the
data, and the controller chip makes two copies and makes sure
that both drives complete the write command for the data. Doing
so reduces the work the host processor has to do, and speeds up
the transfer. Otherwise, you could just find some Windows software
that does RAID or dynamic disk etc, and let the software do
all the work anyway.

HTH,
Paul
 
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