RAID Frame Size

[Just D]

I saw on the Internet that it's better to install it 64 KBytes as the RAID0
Frame Size if we're gonna use huge files and 32 KBytes as a general
suggestion for all other purposes. Also several people wrote that they are
using 16 KBytes and pretty happy with that. Does anybody have any experience
with these values, maybe made some detailed tests with these sizes? Probably
it depends on the hardware as well. The machine is pretty powerful - Phenom
3.75X4, 8RAM, etc. And I'm going to install three 1-TB drives as RAID0 using
the mobo built-in controller. And I'm expecting to write huge files,
probably up to 6-8 files simultaneously from the DVR card. So I guess 65
KBytes is great.

Does anybody have a MB built-in RAID controller supporting bigger values?

Just D.

 

[Colon Terminus]

You might consider a larger stripe size.
I'm running 3 SSD's in a RAID 0 and after much testing setteled on a stripe
size of 128 KB where throughput peaked at 675 MB/sec for large file random
read/write operations.

You also need to take into consideration that soon all hard drives will use
4,096 byte sectors instead of the cureent 512 byte sectors. Seems to me that
the larger sector size would dictate larger RAID stripe sizes.

The best thing, of course, is to do your own testing. With imaging software
ii's quite simple to test, change stripe size, reload the Array image and
test again..

That way you can choose a stripe size that's best for your particular
hardware configuration.

 

[Just D]

Hi Colon,

You might consider a larger stripe size.
I'm running 3 SSD's in a RAID 0 and after much testing setteled on a
stripe size of 128 KB where throughput peaked at 675 MB/sec for large file
random

To my surprise I found that my mobo has only 2 options - 64 KB abd 128 KB. I
remember the older controller (still in use on another machine) with the
blocks from 2 KB up to 64 kb.

read/write operations.

Yes, I was able to get 320 MBytes/sec while copying files, that was very
impressive for the RAID0 with three 1-TB disks, all working in SATA 1.5 GB
mode, even not 3 GB that they don't support.

The best thing, of course, is to do your own testing. With imaging
software ii's quite simple to test, change stripe size, reload the Array
image and test again..

To my surprise I was unable to install Win7 on this RAID!!! I made a few
photos of the process. It was very interesting. I'm not new to these games,
I spent many years on this field and know exactly what to do and how. But it
was the first time when OS was not able to install itself with no visible
reason. I remember many different headaches, big drives, 48bit supporting
controllers, different geometry translation by different systems, etc. But
this issue... I configured RAID0 with BIOS, Win7 starts installing, I load
the RAID driver from USB, it's still ok, I can even ignore this step since
Win7 knows about my chipset and recognizes the hard drive/raid with no
issue. Then the mistery begins. First Win7 wants to cut 100 MBytes out to
install the system files. I never saw that with Windows before. I know that
Linux pretty often uses a separate partition to load the kernel (200 MBytes
for several different generations of Kernel). So this idea was stolen by
Windows. But it's ok, I left 100 MB to the system, then created a new
primary logical drive around 100 GBytes (to be honest I tried to create a
smaller one - same results)

http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-1.jpg

for the system. It allowed me that and started installing. Unpacked all the
files, then showed that installed features,

http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-2.jpg

updates... Suddenly it showed that it can't switch to the next installation
step and recommended me to restart Installation. Pressed OK, a few seconds
later it showed me the Installation screen again, same checkbox for
license..., etc.

http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-3.jpg

then agreement, driver browse/load, same disk partitioning... Next step -
this time the files have been unpacked way too fast, I guess they were
cached on the preformatted disk (RAID). Same.. features, updates, then the
same warning. Back again. This time I pressed reset, reconstructed RAID0 to
completely kill the info, and allowed Win7 to take care of the drives in
full auto mode. Few minutes later I got the same results. Btw, the disk that
I'm talking about, is 3 TB consisting of 3 1tb drives working as RAID0. BIOS
took care of these disks, they are visible by Win7 even without drivers,
etc. So instead of using 100 GB drive that I created for the system, Win7
created a 100 MB partition for the system files, then my custom partition
(marked as Active), then the rest up to 2 TB was marked as the first
unallocated zone (1.8 TB?) and the rest - around 600-700 GB as the second
unallocated zone. So anyway, after at least 10 tries to install Win7 on this
RAID0 I returned back to previous configuration with no RAID, deleted RAID0
created by BIOS, recreated RAID0 by Win7 as a software RAID and finally
started using it. But the question still remains - why Win7 was not able to
install on this machine??? It would be pretty good and extremely fast having
the speed over 300 MBytes per second with continuous reading.

That way you can choose a stripe size that's best for your particular
hardware configuration.

I suspected that. And I tried 64 and 128 KBytes - no way - the OS was not
installed in either one.

Here are the photos once again. Sorry for the quality, I used my mobile
phone to expedite the process.

http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-1.jpg
http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-2.jpg
http://members.cox.net/dshvetsov-home/W7/Win7-Instalation-3.jpg

Just D.

 

[Char Jackson]

To my surprise I was unable to install Win7 on this RAID!!!

In all my life it never occurred to me to install a Windows OS on a
RAID, especially
a) on a fragile RAID 0 array (no mirroring, no parity, no safety net)
b) on an array so LARGE!

I could see RAID 2 or even RAID 5, but RAID 0? Not for me, thanks.
You're way more brave than I am.

 

[Just D]

Char

In all my life it never occurred to me to install a Windows OS on a
RAID, especially
a) on a fragile RAID 0 array (no mirroring, no parity, no safety net)
b) on an array so LARGE!

I could see RAID 2 or even RAID 5, but RAID 0? Not for me, thanks.
You're way more brave than I am.

Not a big deal, I got one more built-in 2 TB for the backups and a few more
hardware external RAID boxes for the same purpose. Acronis helped me several
times for the last 5-6 years. I just wanted to try it out and Win7 failed to
install.

Maybe it can't be installed on the drive over 2 TB size at all? GUID
partition can't be bootable, but it's usable when Win7 is already up and
running. I got 3TB with no issues. But installation was a nightmare.

Just D.

 

[Colon Terminus]

You might consider a larger stripe size.
I'm running 3 SSD's in a RAID 0 and after much testing setteled on a
stripe size of 128 KB where throughput peaked at 675 MB/sec for large file
random read/write operations.

You also need to take into consideration that soon all hard drives will
use 4,096 byte sectors instead of the cureent 512 byte sectors. Seems to
me that the larger sector size would dictate larger RAID stripe sizes.

The best thing, of course, is to do your own testing. With imaging
software ii's quite simple to test, change stripe size, reload the Array
image and test again..

That way you can choose a stripe size that's best for your particular
hardware configuration.

Yeah, I ran into similar problems. Here's what I did to solve it.

I installed Windows 7 onto a spare drive in normal (AHCI) mode.
Then I followed the instructions here:
http://www.candiedbrains.com/2009/06/20/ich9r-raid-with-windows-7-or-vista/
Then rebooted, set the controller to RAID and the RAID array as the boot
drive.
Rebooted with my cloning software CD and cloned the install onto my RAID.
Rebooted into Windows 7 and have been enjoying it ever since!

Good luck to you.

 

[Just D]

Colon,

Yeah, I ran into similar problems. Here's what I did to solve it.

I initially installed Win7 in IDE moce, then had to correct the registry
value to start AHCI, it worked and I'm using it in AHCI mode now.

I installed Windows 7 onto a spare drive in normal (AHCI) mode.

So this process can be skpped. I do have a working AHCI version.

Then I followed the instructions here:

http://www.candiedbrains.com/2009/06/20/ich9r-raid-with-windows-7-or-vista/

That's good, because I saw one article recommending to replace the driver
path, its GUID like registration, etc., right in the registry. It sounds
like dancing blind on the mine field. ...even having a complete Acronis
backup.

Then rebooted, set the controller to RAID and the RAID array as the boot
drive.
Rebooted with my cloning software CD and cloned the install onto my RAID.
Rebooted into Windows 7 and have been enjoying it ever since!

This part is simple. The hardest thing is to get it working without killing
it. Completely. I guess there is a big risk here since I was not able to
install Win7 on the 3 TB RAID0 and I wrote here in this thread about my
experience a day ago.

Good luck to you.

Thanks! I need that. I'm just afraid that MS is simply not ready to use the
huge drives as the primary ones to boot from, in my case RAID0 with 3 TB
total.

Just D.