Software versus hardware RAID 0

[McGraw]

I tried to set up a Hardware RAID 0 on my nforce 4 board.

No matter what, I couldn't get the drivers to take and eventually gave up.

I set up a software array in XP instead.

I have 2 questions.

1. What advantages/disadvantages would a hardware array have over a software one.

2. Could I convert my software array into a hardware one?

Thanks.

Software RAID has higher rescource overheads than a hardware based RAID

Yes you could, but you'd lose all your data...so not so much of a convert but a re-build!

For more info - see this linky!

[Tristan]

Originally Posted by lsainsbury

Software RAID has higher rescource overheads than a hardware based RAID

Yes you could, but you'd lose all your data...so not so much of a convert but a re-build!

For more info - see this linky!

Bear in mind that many "hardware" Raid chips, particularly the cheap ones that tend to be built into motherboards (nVidia, I'm looking at you), are actually "fake RAID" modules. With these, all the work is done by the drivers rather than the actual hardware. Sort of the Raid equivalent of a winmodem.

In this case, there is approximately zero difference in performance between a "hardware" Raid array and a software one.

[The Jackal]

Originally Posted by Tristan

Bear in mind that many "hardware" Raid chips, particularly the cheap ones that tend to be built into motherboards (nVidia, I'm looking at you), are actually "fake RAID" modules. With these, all the work is done by the drivers rather than the actual hardware. Sort of the Raid equivalent of a winmodem.

In this case, there is approximately zero difference in performance between a "hardware" Raid array and a software one.

Except that if you've installed fake raid via windows and then try to install linux :

Linux obviously will not see the RAID just 2 seperate disks

(think I've seen a few posts on this forum complaining about ubuntu not being able to see the disks during install)

I'm currently going through this pain at the moment I'll just buy a SATA RAID card - anyone know of a decent one that does hardware RAID ?

---------- Post added at 02:03 ---------- Previous post was at 01:15 ----------

Interestingly this seems to be very 'do-able' with the use of dmraid.

This guy didnt have much dice but it's lead me onto some great resources.

http://ubuntuforums.org/showthread.php?t=297049

which led me to : http://www.ubuntu-in.org/wiki/SATA_RAID_Howto

Which has the gist of what to do making understand where the problems were (this guide aint correct I tried it and failed).

Since Fedora supports mdraid I'm sure I'll find a way to get ubuntu running it.

[Aragorn]

CrC - this is the card I was thinking of getting. Not used it myself yet, but have used Adaptec SCSI cards in the past with good results.

[The Jackal]

Originally Posted by Aragorn

CrC - this is the card I was thinking of getting. Not used it myself yet, but have used Adaptec SCSI cards in the past with good results.

LOL

DONT ! Its fake too :o

I was checking this list night whilst looking for a card....

http://linuxmafia.com/faq/Hardware/sata.html

I too was thinking adaptec do proper RAID duh they dont expect for their high end cards !

Appears that proper Hardware RAID is gonna cost u dearly at leadt £150 plus.

[Aragorn]

Someone Rep that man! (I would if I could!)

[The Jackal]

Originally Posted by Aragorn

Someone Rep that man! (I would if I could!)

LOL spread some rep around u stingy git

Think I will continue to try the linux mdraid route I just saw that cluster size can be an issue in NTFS maybe thats why its not being recognized.

I remember setting up the RAID from the bios with 64k cluster size which I think should have been 16... will try it when i get time

---------- Post added at 13:00 ---------- Previous post was at 11:04 ----------

Damn I'm good (1st self gloat to the day excuse me plz) : Looks like I might be right about the cluster size does mean re-installing windoze though :o

http://forums.gentoo.org/viewtopic-t-244941.html (read his last edit at the bottom of the page)

http://www.linuxforums.org/forum/red...ia-vt8237.html

[GeoffW]

I was talking to someone at HP in their performance centre and I asked him a similar question about the overhead of software raid compared to hardware.

His answer was that basically there is so much processing capacity (in admittedly supercomputers) that the overhead in software raid was not really an issue. i.e nowadays it is negligible.

[The Jackal]

Dual booting windows and linux with my chipset seems not possible at the moment..... given up

So only one OS can use the RAID.

Pity really as windows was flying on raid0 - hd benched at a stagering 95MB/s

I've split the RAID up and am now gettin 53MB/s in windows and 60 MB/s in linux grrrrrrrrrrr

Might just let windows have the raid (afterall Windows needs all the fastest hardware it can get just to run reasonably) and stick linux on an IDE

[The Jackal]

Finally did manage to get this running !

Got 2 raid cards in my machine 1 for windows 1 for ubuntu. dual bootable

Boots into ubuntu in around 20seconds see chart.
And speed usage is unbelievable still beats windoze though

Maybe I should write a HOWTO as the ones I were following were incomplete

[Aragorn]

How did you generate that chart? Looks intriguing!

[The Jackal]

Originally Posted by Aragorn

How did you generate that chart? Looks intriguing!

bootchart : http://www.bootchart.org/

[Shaun]

Originally Posted by CrC-3rr0r

Finally did manage to get this running !

Got 2 raid cards in my machine 1 for windows 1 for ubuntu. dual bootable

Boots into ubuntu in around 20seconds see chart.
And speed usage is unbelievable still beats windoze though

Maybe I should write a HOWTO as the ones I were following were incomplete

A how to for windows would be much appreciated by me