Should I use raid 0? What are the cons? 6

[Atomicboy22]

Hello. I just bought 2 160G WD hdd's on sale. I'm going to replace my current 120G with them, and I bought 2 in hopes of trying out raid 0. I want as much performance as possible

I'm just trying to find out more info on how secure this array actually is though. In other words, I don't wnat to set this up to only have a bad sector on one drive crop up in a month and the whole array becomes unuseable due to this. I have been reading as much as I can about raid 0, but no one really addresses the issue of how stable it is. I know that if one drive fails, the whole array does, but how is the array effected by bbad sectors? What else can happen? How stable is a raid 0 array? Should I bother, or should I just use both drives as a regular IDE master/slave and not worry about raid?

I was surprised to see how little most people actually know about raid, and how uncommon it actually is. From what I read on it, it seems like the next best thing, but there must be something that is preventing people from using it, and this is what I'm looking for.

Please help, thanks a lot

 

[Atomicboy22]

one other question before I screw it all up, what block size should I use for my array? I read the max, 64k is the best for performance in a riad 0, where the min 4k is the best for servers in a raid 1, is the right? For what I want it for should I do 64k or lower?

 

[lesgray]

Slipstreaming should work for you. As you may have found, there are a large number of websites that give you information on setting up the boot cd. I had completely forgotten about the HD size limit pre SP1, as all current install CDs have it incorporated.

As for block sizes, you are probably better off with the larger 64K ones. Raid speeds with the larger block size tend to favor applications that use larger files, while the smaller block sizes work best when ou deal with numerous smaller files. Given that you are talking video editing, the files are probably going to be huge, so 64K will work out best. I believe in general, the 64K size is the way to go, unless you have very specific reasons to do otherwise.

Les Gray

http://www.creartec.com

 

[SYAR2003]

Some say 16k others say 32k stripe size on two disk raid 0 ,but it really depends on you avarage file sizes on your volume .

 

[lesgray]

Actually SYAR2003 has a better idea with his suggestion of 16K or 32K blocks, rather than the 64K I suggested.

16K or 32K blocks would most likely be better, as your computer is not solely a video editing box. Again, the key is your average file size. Once you set the block size, the smallest amount of room a file will take up is that size - so a 1K file will occupy 32K with 32K blocks and 64k with 64K blocks. Lots of tiny files will eat up your hard drive space really fast with 64K blocks. Of course, 320GB sounds like a lots of space, but we've all had drive space we thought was ample eaten up in no time

Found some quick links regarding block sizes:

http://www.extremetech.com/article2/0,3973,1154872,00.asp

http://www.sudhian.com/showdocs.cfm?aid=218

http://www.tweakhardware.com/article/what-is-raid/

Discussion thread with some comments about block sizes after a bit:

http://www.abxzone.com/forums/showthread/t-60020.html

Les Gray

http://www.creartec.com

 

[Atomicboy22]

Thanks guys, from what I read on those sites and a couple others, since my limit for block size is 64k, i think either 32k or 64k will benifit me the most, since my system is mainly for games, and second video, though I have no idea what my avg file size would be. I guess window files shouldn't be taken into consideration for this, as this is stadard on any machine (linux the same), as these will be primarily the majority of small files on a system similar to mine, on average.

Let me know, 64k or 32k, what you think, based on what I use it for, games, music, and video as a secondary (and internet and email, though this shuold really have no effect... hmm well maybe the cahce...)

 

[SYAR2003]

Atomicboy! I think you should descide this yourself.
(but not 64k)
Large stripe size stores better but hurts performance .
Something in between would be my choice.


Some tests:

http://www.hardwaretech.info/guides/configure_bench_raid_6.php

Quote:
RAID 0 block stripe size:
Users report generally best results with a 16K or 34K stripe size. Anything above 34K seems to reduce performance and is not recommended unless the array is used for working with exceptionally large files such as in video editing.

http://www.overclockers.com.au/techstuff/a_hdd_shootout/page2.shtml

syar

 

[lesgray]

What Syar2003 said....

: )

Les Gray

http://www.creartec.com

 

[Atomicboy22]

Thanks guys, I think you've both built quite an informative riad 0 manual here, hope it helps others also. I will post back after I attempt this tonight, and let you know what happened. Thanks again

 

[TekTippy4U]

Atomicboy22;
I've only managed to get thru 1/2 this very useful thread so far;

I believe you can create an XP SP1 install disc if you look here, it'll tell ya how....(How to graphics too, haven't used it myself though, maybe everyone can have a look see, and comment)

http://www.tacktech.com/display.cfm?ttid=157

-ROXIO

http://www.tacktech.com/display.cfm?id=160&object=article.cfm

- NERO
I'm reading on folks.......

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[TekTippy4U]

Ok...I see it's been answered..cool ,fellas.
Thanx Syar and Les...good stuff!

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[Atomicboy22]

Ok, set up everything ok, installed xp using my slipstreamed version w/sp1. Got into xp, when I try to go into device manager it gives an error saying mmcndmgr.dll is currupt is path is not in system root. Also, when I tried to do the updates, I d/l them all, then it x'd out all of them in the summary page, and said sys needs to reboot, now if I try to go back into that, or do another update, ie crashes, it appears windows is messed up. I was going to try to reinstall, however I can't seem to figure out how to boot from the cd anymore, as my array is set to boot from array, it doesn't even look at my boot sequence anymore.... Please help.. I have no idea what to do.

 

[lesgray]

You can download mmcndmgr.dll from

http://dll.yaroslavl.ru/index.php3?download=mmcndmgr.dll&ver=1

TO boot from CD, go into the bios and set the boot order to CD first and take the HD/raid completely out of the lineup. You just have to remember to put the raid back in the lineup after you install Windows and do the first re-boot

Les Gray

http://www.creartec.com

 

[SYAR2003]

Atomic ! i see yhat you were struggeling .
please use this pre sp2 hotfix from MS$.
Prevents data corruption.

http://support.microsoft.com/default.aspx?scid=kb;EN-US;331958

 

[lesgray]

Right on SYAR2003, good catch...

Les Gray

http://www.creartec.com

 

[Atomicboy22]

LOL thanks, but too late

I tried that slipstreamed disk 3 times, with the same results each time, then I tried my normal xp pro disk, no sp1, figuring my updated third party raid driver would therefore have the latest driver to recognize the drives and the arrays, and it appears I was right, installed xp, all the service packs and driver updates and mobo updates, and everything appears to be fine now, windwos sees the enitre 320G raid 0 array, and everythign is installed right.

One thing bothers me though, I read somewhere that if you didn't use the sp1 to see hard drives, that it would only recognize 137, as we discussed, but if you did a controlled update and it then read the drives propperly (even without sp1), it would still technically only be good for 137G, and anything after that could get corrupt. I only read that once on a board somewhere, but it stuck (as it apply's to murphy's law, and my name might as well be the murphy of all murphy's).

Does this sound right, or since I used the latest third party drivers, and installed xp pro w/o sp1, 320 drive (array) was recognized (so it appeared), formatted, and installed upon, then updated to the latest everything, should everything be ok?

btw I haven't noticed anything signifigant in speed increases yet, shouldI notice anything in everyday window operations, or only in games/imaging/sound editing applications?

Thanks

 

[lesgray]

I believe you should be ok now. I don't recall anything like you mentioned about anything past 137GB, but maybe SYAR2003 has.....

Speed is a relative thing. You shsould notice it when you are running games or doing the video/graphics editing.

Les Gray

http://www.creartec.com

 

[IslandCustom]

Still better off with two smaller RAID drives for the OS and apps, and a large IDE storage drive for the video. FYI, increasing RAM to greater than 512MB usually won't speed up video compiling -- but a separate physical drive would.

 

[TekTippy4U]

Would putting the swapfile at the beginning of another drive on it's own partition help?
No neccesarily in conjunction with RAID, I've heard that only putting the swapfile on a separate physical HDD would help, not a new partition on same drive...this is because the disc reads/writes faster on the outer part of disc, where the RPM's are higher, and there are more sectors/tracks per inch.
I'm curious as to how this would work in a RAID array, especially with striping involved across both discs.

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[Atomicboy22]

Well les and syar, everything seems to be good, set up norton and sygate this morning, so I just have to install all the little crap now, but she's purring like a kitten now

as tektippy mentioned, would it be benifitial for me to have the swap on another drive outside the array? I'm probably going to remove the 40g I have in my "server" and replace it w/my previous 120G, which might be faster anyway, because the 120G is 8M cahce, but ata 100, where the 40G I think is 2M cache, but ata 133, either way it's going to be the 40G that I add as a sec. do you think the page file should be there, on lef tin the array. I know in a regular master/slave it's said to be faster on the slave (tried it myself, didn't notice a thing), but I have no clue for my setup. I guess theoretically it shoudl be faster, 3 drives reading and writing should perform better than 2, right? Let me know. Otherwise everything works great and you two were all the help to me.

Oh btw, I bought a UPS because I also heard power outages can cause problems with raid 0, and seems in teh last six months people have enjoyed plowing into power polls in my area a lot more the in the past, so I thoguht this might be a good idea, I bought a acp 100va, let me know if it's really required for this or not, because it was on sale for $99, but I still don't want to have it if it's not needed.

Thanks everyone! Have a good one tonight!

 

[SYAR2003]

Hi Atomic!
Nice to hear you got all up and well.
Something must have went wrong with the slipstremed cd i guess.
I have only the RTM version of xp-pro(the bought one) .And have been using slipstreamed copy w/sp1 since i made it with no problems.

As for pagefile it will not be heavily used as i'm sure you have 512MB or more ram .

But as you say and tippy it's usage will be smoother if
it's on another physical drive than the os .But dont have it on a 2MB cache drive , then it's more desirable to have it on the raid .
If you install the 120GB w/8MB cache you can have it on this .

Just try out the different options set the pagefile on the
drive you want and restart .
Best is to use a fixed size (min=max) 1,5 times the physical installed ram is the default windows calculation , and can be used to set the new pagingfile on
the drive you select for it.

Have a happy new year.
And thanx to you to .
regards
syar