hi.. i need some advice with this raid system im building!

im new to raid and im trying to make sense of it all.

my first question is what type of file system do people prefer? and what system is best for gaming / reliability / lite application work?

RAID array: A group of hard drives linked together as a single logical drive. Must be connected to one or more hardware RAID controllers, or be attached normally to a computer using a RAID capable operating system, such as Windows XP Professional.

Striping: A procedure in which data sent to a RAID array is broken down and portions of it written to each drive in the array. This can dramatically speed up hard drive access when the data is read back, since each drive can transfer part of the data simultaneously.

Mirroring: A procedure in which data sent to a RAID array is duplicated and written onto two or more drives at once.

any help would be fantastic.

thanks

glen

That's all pretty self-explanatory. The best solution depends on what you're going to be using the drives for.

If you want speed in loading software or copying data, stripe it. If you want the most space then join it and if you want to make your data safe, mirror it.

With more drives you can create combinations of those, it all depends on your budget and purpose.

thanks mate yeah ive just got some more info on RAID 0+1 Striped array with mirroring.. it a bit advanced for my skills but ill try see if i can get it going.

this is a system for my uncle i stupidly put my hand up for him to build :( money wasn't an issues when he got all this hardware so its some good stuff!

For reliability of data, something like RAID 1 is what you want. But if this is for general use I wouldnt bother to be honest. I can see it ending in tears :)

raid 10 ftw! but on a home machine it's a bit overkill. I reckon raid 1 would be fine if you want safety of data, or raid0 if you just want a bit fast logical disk.

RAID 1 and 0 are most common as it only requires 2 drives as a minimum.

RAID 0 = striping, performance based but if you lose 1 drive the lot is gone!
2 or more drives have the data spread across them and are all only seen as 1 drive in the operating system. So as the data is called they system has multiple drives feeding it so while one is sending its bit of data the next can go find its bit and send it when required hence eliminating some of the search times.

RAID 1 = mirror, redundancy so if one drive fails you replace it and it rebuilds.
Also only seen as a single drive in the OS, essentially it keeps your data safe from being lost in the event of a single drive failure.

All the other forms require 3 or more HDD's and are a combination of performance and redundancy. In short the more drives in the array the faster it will go.


I was interested in the whole raptor v raid0 thing a little while ago and having the luxury of playing with any drive setups I like at work I benched a bunch of different setups.

74 or 150g raptor data read was about ~ 75 mb/s
2 x 7200rpm seagates in RAID0 ICH9 ~ 125 mb/s
5 x 7200rpm seagates in RAID5 ICH9 ~ 200+ mb/s (IIRC) <- sounded farken crazy when loading the OS ratatatatatatatat :)

With the insanely low prices of regular HDDs at the moment it is better to go with a RAID0 setup that spend more money on a single raptor IMO. If you have buckets of cash then by all means go for a RAID0 with multiple raptors though.

last edited by rubba-chikin at 17:06:07 04/Aug/07

wow thanks man thats a huge help.

74 or 150g raptor data read was about ~ 75 mb/s
2 x 7200rpm seagates in RAID0 ICH9r ~ 125 mb/s
5 x 7200rpm seagates in RAID5 ICH9r ~ 200+ mb/s (IIRC) <- sounded farken crazy when loading the OS ratatatatatatatat :)

bloody oath =)

Battlefield takes twice as long to load up since I broke my stripe.. and that's on a crappy old Intel 945 ICH7r. It'd be good to have a controller that could do 200+ mb/s, but I figure my old s***heap wouldn't keep up. I'm thinking an Intel E6850 for the next upgrade. It seems good for the bucks

price vs performance vs safety = 3x320gb Raid 5. nuff sed.
Gives you 640gb of storage, crazy fast performance, great safety (parity) and all for under $300.

this is a system for my uncle i stupidly put my hand up for him to build :( money wasn't an issues when he got all this hardware so its some good stuff!

If money isn't an issue and he reeeeeaaally wanted redundancy then go with RAID 10. If RAID 10 is too exy just go with RAID 1 and a good backup drive like external USB thingy.

Just remember this, RAID != Backup.

with drives as cheap as they are, you have so many options

my primary boot drive is 2x300gb in raid1
secondary file storage raid is 3x320gb raid5
third raid being built atm (required PCI-X sata) is 3x500gb raid5 with provisions to keep adding as many drives as I want

500gb drives are $170, just get a few of those
if you do raid5 you get N(number of drives)-1 * size of smallest drive, so 3x500gb drives is 1TB for $510 with redundancy, your array will continue to function if a drive fails.
you can add another drive and you get the whole size of that drive because you've already got a parity drive

At work we just put in a SAN constiting of 16 x 750Gb SATA drives, running a combo of RAID 10, RAID 5-9, and RAID 5-5. Gives us around 9Tb usable. Will add fast FC disks to it in a year or two.

I hear that trent is the master of raid sets and triumph engine storage

wow so many options! thanks guys.. i guess the best way to do it is to try a few different options.

Only one little hiccup. The raid 5 "write hole". I think you should be aware of that before configuring someone else's system that you won't have direct control over.

Raid 0 is not always faster then HDDs, and even when it is, its not much faster.

Raid 0 has more points of failure then HDDs, ie. if the chance of losing all the data is roughly the chance * the drives ... well not quite, but if you did prob and stat at school you should be able to work it out

If you are getting raid 0 ... I laugh at you.

wiki

RAID 0 is also used in some gaming systems where performance is desired and data integrity is not very important. However, real-world tests with games have shown that RAID-0 performance gains are minimal, although some desktop applications will benefit

anandtech

At this time we still do not recommend RAID 0 for most desktop users due to the lack of widespread performance improvements and potential data integrity concerns with it.

anandtech again

If you haven't gotten the hint by now, we'll spell it out for you: there is no place, and no need for a RAID-0 array on a desktop computer. The real world performance increases are negligible at best and the reduction in reliability, thanks to a halving of the mean time between failure, makes RAID-0 far from worth it on the desktop.

pcguide

A lot of people seem to think that implementing RAID 0 is an easy way to storage nirvana, but for "average use" it may not help performance nearly as much as you might think.

storagereview.com

To summarize, RAID 0 offers generally minimal performance gains, significantly increased risk of data loss, and greater cost. That said, it offers the ability to have one large partition using the combined space of your identical drives, and there are situations where the benefit of the benefits outweight the disadvantages. It is your computer: The choice is up to you.

There is 1 important rule with computers.
KISS
Keep It Simple Stupid.

Raid 0 is not simple.

KISS
Keep It Simple Stupid.

hehehe reminds me of my English teacher who gave me the same advice after I tested her with words out of the dictionary that she didn't know the meaning to.

Keep it simple... maybe if you are a newb.

I had my doubts and made an array of RAID0 just as an experiment as I wanted to know a bit more about it. So far it has made a world of difference in installing/loading programs.

For a real world example installing CMR DiRT on my single HDD took forever (it is ~10gig installed). I estimate with my RAID0 setup it took roughly half the time if not less to get it on there.
It has made an big difference gaming wise too. I am now consistently the first into new maps 10-20 seconds before anyone else is.

Those results are grounds enough for me to keep running it.



The 2 most important things you need to consider are -

1) Would having to reinstall my OS and games/apps be the end of the world? (With partition cloning tools this is very very easy these days). If the answer is yes then RAID0 is not for you.

2) How much space will you need for your OS + games + applications, then get smaller rather than larger HDD's for the RAID0 otherwise you will have a large but untrustworthy space to store things on.

If you are smart about it and know what you are doing it is a great way to boost performance. I don't care what any review says as I have experienced it myself and can safely say it has made a very noticeable difference in my case.

last edited by rubba-chikin at 19:45:37 05/Aug/07

I hear that trent is the master of raid sets and triumph engine storage

you know it was really just a ruse, we just firewalled you off from the site and used that excuse.

MWHAHA

here's a great video about scalability from the guys at youtube ( hosted on google-video ... ironic? )

Anyways they talk briefly about their Databases being stored on massive RAID10 arrays. They were having performance issues and discovered that giving linux 5 x RAID1 volumes and using software RAID0 to join them up gave them an extra 20% ( i think it was ) performance as linux saw 5 logical disks, rather than just 1.

Thought it was semi-relevent here. They have a bunch of neat tricks like this that they had to work out to keep things running smoothly.

ZOMG my map loads so quickly now, so I can run around like tool banger with a knife for an extra 30 seconds while I wait for everyone else to load.

ZOMG I can install stuff so fast, which is lucky cos with my super 8 drive raid 0 set I seem to reinstalling everything every other day.

Exactly, you can have fun sitting there at a LAN watching the installer bar while I am already playing.

Being first into maps lets me choose whatever the hell I want, for example in Insurgency I am basically guaranteed the squad/cell leader spot if I so desire it.


I honestly don't see the big risk with it as long as you don't dive in uneducated.
I have all my important data on other HDD's and if my array was to die... oh no replace HDD, ghost preloaded OS over, install games and I'd be back up and running within the hour.


For anyone interested I just had a system with 3 x Seagate 7200rpm RAID 5 on ICH9R and that benched at ~104 mb/s, so a bit slower than a 2 x HDD RAID0

what are you using to bench, and is it read/write/sequential/random?

You mean there's more to benchmarking than timing how quick Counterstrike loads up ?

LOL STINKY

Using SiSoft Sandra to bench, the scores I have posted are just the read bandwidth test.

cheers
I wanna test my drives

121 MB/s 2 x 15k rpm sas disks in raid1

jim's hd speed epeen is massive

in real terms, it means that I've gone from blahnana laughing at how long it takes me to load a COH map, to me laughing at how long it takes him

well worth the crazy cost overhead imo

Ive run RAID0 for years, and to be honest apart from installing stuff and doing hardcore caching stuff (after effects etc) its not THAT noticeable. Also its potentially unreliable as s***! (I once used IBM 40gb deathstars in RAID0, that was f***ing painful).

For RAID1 Ive yet to see it be nothing than a pain (ie: drives going out of sync and having to be rebuilt). While it may save you one day, setting up something like rsync to an external drive is just easier, less pain and an actual backup solution.

Unless your absolutely desperate for speed (like caching in AE or doing print media / CAD) I'd suggest leaving RAID to computers that need it. If your doing games, just spend the extra money you save on something like O&O defrag.

LOL, I had a raid 0 setup on two IBM Deskstars for over 3 years! The performance was great but I knew what I was doing....most of the time :)

For RAID1 Ive yet to see it be nothing than a pain (ie: drives going out of sync and having to be rebuilt). While it may save you one day, setting up something like rsync to an external drive is just easier, less pain and an actual backup solution.

that's been my experience too - when I used a cheap s*** controller

Of course a decent controller helps enourmously, unfortunately most onboard raid controllers (3112/3114/nforce4) seem pretty problematic when its comes to RAID1 during out-of-sync.

You mean there's more to benchmarking than timing how quick Counterstrike loads up ?

my personal benchmark is how quickly it takes the cad boys over at 888 race engineering to load up Craig Lowndes car onto the screen. Every panel, pane on glass, every screw. I don't get to do this everyday sadly, but the experience sure has changed my outlook on pc performance on the whole.


I used to think that broadcast-level video editing led the way in terms of judging desktop pc performance.. it's high end CAD dudes. I can only hope for the days that pc videogames meet this standard. The physics alone make the mind boggle

surely Amd have something that's on-par with the Intel ICH9r, or old ICH8-7-or-6r ViiV standards by now.

there's nothing wrong with going for the cheap-end of the market but bloody hell, stripe-raid has been a part of the best Intel desktop multimedia spec for 4 generations now.

last edited by koopz at 23:02:34 06/Aug/07

which test are you running in sisoft? Physical or Filesystem ?

I did physical first, tried filesystem but it took too long and I got bored

Cool. According to physical I get 175MB/s, Filesystem 138MB/s

that's a 1TB LUN on my SAN ( 16 x 750Gb SATA ) with 2Gps FC. If only our budget stretched to 4Gbps FC and some 15k FC drives....

Over iSCSI to the same SAN I get 97MB/s ( no tuning on the iSCSI network like jumbo frames yet ).

that would load COH fast

You mum has jumbo frames (and you've tuned her!!!)

yes she has, and yes I have.

haha so you admit it

I'm proud of it! we have the most beautiful children.

haha he admits it

hang on ... we are talking about your mum aren't we?

I'm bored of this now, let's talk about 4wd's - how's the suby goin

Pffft ... lets talk about flatheads

obes is a fathead

obes is obese