Hi guy's
Can anone explain to me which setup for Raid is best.I understand the bear basics,but would like to know a bit more.

:)

Nick Y

here you go cockney £$%£% ;)

here

I used 2*40gb drives identical drives, the performance was noticeable

Si

[Edited by super_si - 10/16/2002 8:36:06 AM]

Morning Si,
Ta mate!

:)

To early mate , if your after benchmarks then mine doubled after setting up raid. Ive sold it now and just using 1 82.3GB

if you need a hand ask us ;)

Si

You helping him?

That is a truly, truly scary thought:eek:

That is unless you took comprehensive notes from what I taught you!:p;)

lol :) i did. Not that hard. Setup the RAID BIOS, the think it was F4 loading the OS, then the Revision drivers ;)

Also put them as master on the raid channels.

see rememberd ;)

I've always found the ARSTechnica explanation a lot easier to understand. ;)

Depends what you want - resilience or speed or a bit of both.
That first site doesn't even mention RAID 1+0.

...and remember if you do decide to use a 'striping' solution, make sure you have a rigorous backup policy!!!
I've seen loads of people implement 2 disk striping without realising that if they loose one disk they loose all the data.

Ah, but would you stripe across mirrors or mirror two stripes? ;)

LOL at DrEvil

:D

I'll be more constructive later... in the meantime checkout this site:

http://www.cuddletech.com/veritas/

Although it talks from a veritas point of view, some good stuff about raid theory on here.

If you are looking for an enterprise level solution I can give you some pointers.

One thing I would say is, it never hurts to apply the HA principles to the hardware you are running on, as well as raid.

Rgds, Alex

PS. in part my previous comment was serious, there are benefits of using striped mirrors over mirrored stripes. :)

[Edited by DrEvil - 10/17/2002 2:51:52 PM]

If you're using integrated raid controllers on the mainboard, wasn't the differences in performance neglible ?

I've never tried it, but remember reading it somewhere. I thought increased performance came from a proper hardware based raid card that was pretty much host cpu independant.

Here's a good primer and review:
http://www.anandtech.com/storage/showdoc.html?i=1491

Darren(M3) was that aimed at me? (added to make sense to this thread after my previous edit).

its more recovery benefits - ie. if a disks goes bad, only one segment of the stripe will need to sync - not the whole stripe.



[Edited by DrEvil - 10/17/2002 3:15:43 PM]

Sorry DrEvil, to clarify - I wasn't referring to your comments.

Just thought a 13% increase in performance wasn't that staggering for the cost of 2no. drives.

-DV

Darren - sorry, I removed the comment after you replied - put it back now.. plus in part one of the benefits of a striped across mirrored devices..

Cheers, Alex

Quote
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Ah, but would you stripe across mirrors or mirror two stripes?
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Depends what app you are running? 0+1 or 10

for increased performance go for mirroring, when we are doing big SAP or Oracle benchmarks all the disk arrays are mirrored and we use the smallest possible HDD drive size - more spindles faster record read times.

for resilliance the newer Advanced Data Guarding techniques allow two two drives in an array to fail and still be able to re-produce the missing data.

Hardware based RAID controllers are there to take the strain off the main CP, you normally get additional functions such as predictive read ahead and the ability to do read/writes from cache memory rather than having to comitt to disk all the time.

That's my 2p worth for the night.

Phil