RAID-0 Striping

[Pedro_The_Swift]

How important is BLOCK size in reality?
The array's ONLY function is performance.

I have read a smaller size will be faster?
say 64kb?




and----


can I back-up a striped array onto a single disc?

TIA,,

[Grizzly_Adams]

Smaller block size doesn't necessarily equal better performance. It all depends on what types of files you will be storing on there - smaller files = smaller block size. Larger files = larger block size.

If you have larger files then a larger block size will mean less reads from the disk to pick up the entire file.

If you have smaller files then a block size larger than the file will mean the disk has to read a heap of empty space before delivering the file.

.. and yes you can backup your RAID-0 to a single disk, in fact you can back it up to anything it won't matter.

[spudboy]

What are you using the disk for? Is it large media files, which can be gigs big, or for database access?

If you are chunking around large quantities of data then the larger block size can be more efficient, but I'd suggest just using the default unless the data you're storing is universally of one type.

Re the backup - the disk controller "abstracts" the fact that the hardware is striped, so when you copy/backup from it, the destination has no idea of how it was stored on the original disk.

[greg-g]

Be careful of Raid 0, we had it on a computer and had all sorts of problems with backup, defrag, and other issues. The computer was fine with basic operations, but we didn't notice any speed difference when Raid was removed.
I never really sorted out what the issues were, but it appeared to be dependant on if you had hardware or software Raid. Hardware Raid is certainly what you get with an add on Raid card, but my testing appeared to indicate that the mother board Raid (Gigabyte) was software Raid. None of the free utilities, or my regular maintenance programs would work correctly.
I won't try Raid 0 again mainly as the feel the gains are very marginal with normal usage, and any problems are compounded.
I would love to see other peoples comments on this issue as I'm no expert.
My research on strip size indicated it was best to go with default settings.
Have fun
Greg

[Pedro_The_Swift]

the array is a performance trial for games,,
and,,,
(and I am SERIOUS about my games)

I need to arrange a back-up for my PC:angel:,,


so I thought I'd do both,,

purchase two 500GB WD caviar black HDD's
(5year warranty and speed. dont say raptor,,)

stripe them,,
and back-up to the 320gb I have now,,

the thought process is --:angel:
just copy the 320 across to the new array--
then re-format the 320 for back-up duties,,,,




as a $ performance improvement,,,, ?
who knows?

compared to a faster cpu?
$140(array) V over $350(quad core)

more/faster ram? [an argument in itself ;)] 2 slots available, 2 slots filled, 4gb total, speed=DDR2-800.
would 8gb (or 4gb of 850)make a BIGGER difference?
?

faster graphics?
Geforce GTX 295?
= $660

or just take pills/coffee before playing?

:p

[Roadrunner]

Have you thought of the WD Raptor drives. I replaced my HDD with a Raptor (10000rpm) and I think its way faster now. Also I play no games.

Matt

[Pedro_The_Swift]

yea, Raptors are cool,,
but at $190 for just 74GB,,
(though a 150GB IS available now,,,)

If I have over 60GB of games,,
plus OS,,


raptors put it in the Quad core realm,,,

[mjm295]

I only ever use raid 0 for serious databases on servers at work. Never found it useful at home. We would match the block size to the block size used in the DB.

You would be better buying a 10,000 rpm disk.

To really notice raid 0 advantages you need to do it over 4+ disk, we generallly use 8 at work.

[hoadie72]

I'm curious as to why you'd expect to see a lot of performance improvement running RAID-0 for game play. Are your games really that disk I/O intensive?

[abaddonxi]

64Gb SSD

Kingston 64GB 2.5" Solid State Disk, MLC, SATA (SNV125-S2/64GB) | Techbuy Australia (http://www.techbuy.com.au/product.asp?prodId=123402&catId=HDD&parentId=HDD_SOLID_STATE_DRIVES_-_IDE)

Nah, maybe not, the first two points rule it out.


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Performance enhances productivity; makes users more efficient
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Guaranteed 3 year legendary Kingston warranty, 24/7 tech support


Is HDD really the bottleneck?

[Pedro_The_Swift]

I have no idea Simon,,
like I said, its about combining TWO needs,,

I only know what I read on the 'net about increased performance,, some people say its considerable.

as for block size,, again there are lots of differing ideas, average file size, maximum file split,
ie, you could have a 4kb block size,, and on a 8000kb file it would maximise storage and the amount of splitting done, which when writing is fine,, but reading such a split file would take forever,,
[have I got that right?]
the black caviers cover FOUR important functions,,
they have a FIVE year warranty,, and are bloody quick for a normal drive. They are cheap! They are big enough.
I can do this and not lose either way,,,,

[Captain_Rightfoot]

Pedro, have a read here.

By definition RAID 0 provides no redundancy. That's really not a good backup strategy. Doesn't windows have something that manages your backup onto an external HDD? Surely they have copied that from OS X by now? That would be a simple cheap and effective backup strategy.

Everyone should have a portable HDD with an image of all your important stuff off site.

[Pedro_The_Swift]

------------

I need to arrange a back-up for my PC:angel:,,


so I thought I'd do both,,

purchase two 500GB WD caviar black HDD's
(5year warranty and speed. dont say raptor,,)

stripe them,,
and back-up to the 320gb I have now,,

the thought process is --:angel:
just copy the 320 across to the new array--
then re-format the 320 for back-up duties,,,,



I agree Captain!:p

[Aussie]

Raid 0 - Min 2xhdds Data is striped across both drives, If one fails you lose the lot. Read/write performace improved over standard single drive and Raid 1.

Raid 1-Min 2xhdds Data is Mirrored across each drive. Has excellent redundancy, if you lose one drive can still function on 2nd disk, also has the ability to rebuild new drive automatically. Downside - Loss of storage space by 50% e.g Buy 2x 1gig hdds and you will only have 1gig storage space available.

Raid 5 - Used for mainly on larger servers - Hot swap plug and play with one drive reserved as a parity drive.

There are also variations, can have Raid 1 + stiping etc requires more drives :)

[Bytemrk]

Pedro,

If you are primary looking at Raid 0 for speed... as someone else here pointed out are you sure its the HDD performance of your system that the games are really stretching?

Have you done any system performance monitoring to try and get an idea where your real bottle necks are?

If you are going to use Raid - as well as the drives the key to a fast raid system is a decent Raid controller. Many desktop main-board raid controllers are not that wonderful. I'd really be surprised if by using raid 0 with only 2 drives you will see any visible performance increase at all.

That said... those Black Caviars are damn good value - I put one in a friends system this weekend -good cheap, long warranty, he's happy

I'd start with some system monitoring.. determine for sure its the disk IO that you need to be focusing on. You may find more ram or faster ram gives you much better bang for your buck.
(Disclaimer: the previous statement is based on absolutely no knowledge of you system and should be ignored should any or part not apply ;):p )

Mark

[Pedro_The_Swift]

UPDATE!

well its all working again,,

someone should have said something about "HDD PRIORITY",, oh, and that there are NO intel raid drivers,,
but something called a "raid Intel matrix manager"

just doing some final copying and then some formating.

then a benchmark or two---:twisted:



if nothing else I now know how to set up a raid array,,