Software Raid 5 vs Cheap Raid Card

[Codesmith]

What I plan on doing to using my 74 GB Raptor as my primary drive and use a Raid 5 for my data.

I already have 3 WD 120's and I can purchase a 4th from a local store for $40 (after $60 in rebates).

My main goal is data security, any performance gain is simply a bonus.

Currently I am planning on enabling software Raid 5 in Windows XP.

Questions.

Any compelling reasons to chose a cheap (<$100) Raid 5 card like the highpoint rocketraid 404 over software raid?

Is software Raid 5 actually going to make my data safer, or is it just going to create new oportunities for catastrophic data loss?

For instance I just discovered that one of my power spliters has a fault and causing two of my hard drives to temporarily lose power when I jarred my case. Windows froze and needed reset multiple times as I was trouble shooting, but none of my data was lost.

If something similar had happeded with two drives in a software RAID 5 array what would happen?

What if after working in my case I accidentally boot with only two of the four drives connected?

Any and all comments/options/speculations are welcome!

I just want to make sure that my excitement over discovering that software RAID 5 is possible under Windows XP doesn't result in my making my data even less secure!

 

[sjonnie]

Don't choose RAID5, it's not worth it and security is poor. If you are going to have 4 WD120s I'd reccomend you use a RAID10 array.

After that...a RAID5 capable card, even like the RR404 is preferrable to software RAID. Software RAID can only be accessed, not suprisingly, through software. At least with a RR404 card you can get access to you data in a system independent fashion, if you are after security, that is more secure than software RAID. RAID5 is naturally harder to recover from in the event of disk failure, software RAID merely compounds the problem further.

If anything happens to any 2 drives in a RAID5 array all your data is lost. In a RAID10 array it is possible to loose 50% of all the drives and still maintain data integrity.

If you boot without 2 drive connected the computer will say the array has failed and you won't be able to access data. You may need to rebuild the array and recover the partition upon reconnecting the drives. This applies to any RAID array.

Just because something is possible doesn't mean that it is advisable.



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[Codesmith]

Software Raid is system independent according to the THG article. They even were able to connect split the drives between different SATA controllers and windows still recognized them.

Also I have a Segate 200 GB that I can use to backup my system drive, so access outside of Windows isn't needed.

Even if I get a raid card or decide RAID 5 is to risky, I will still setup software Raid 5 and test some things, like starting with two drives disconnected, causing a momentary power loss to two drives, moving it to a 2nd PC, overclocking my PC to unstable settings while defraging the raid array and see if what happens after the crash .

Enough fun to justify the purchase of one more 120 drive. And I need a good excuse to force organize and backup all the content of my three 120's to DVD+R's anyway.

Still I am definately considering the RocketRaid 404 as an option.

Newegg shows the RocketRaid 404 as supporting Raid 5, and the user reviews report successful Raid 5 usage, but I haven't found any info on Raid 5 for this card on thier website which causes concern. Supposedly this was added in a BIOS update, so most likely it is also implementing Raid 5 in "software" using the CPU to do most of the work.

I would really like to see some benchmarks showing the 404's Raid 5 performance but I can't find any.

I definately don't have the cash for a "real" RAID 5 card.

I am only considering the purchase of another 120 PATA drive because its on sale for $40 (after $60 in rebates). An additional $90 card is pushing my budget and is maybe more than I want to invest in non-SATA technology.

Raid 1+0 is tempting, but I would either have to buy the $90 card and three more 120's to reach 320GBs. Which means spending $390 then waiting for $180 in Microcenter and Western Digital rebates.

This in the same month as my purchasing $300 in other gear including a 74GB Raptor and a Logitech MX1000 mouse.

So my options are;
1) software Raid 5
2) cheap hardware Raid 5
3) Keep backing up my data "when I feel like it".

 

[sjonnie]

By system independent I meant you can access it from any operating system. Software RAID run by Windows will require you to boot to windows. Under normal circumstances this should be fine, but sometimes when things go tits up you want to run recovery software which doesn't run under XP.

The RR404 card has a BIOS update which permits RAID5 arrays to be created (and swtiches RAID0+1 to RAID10 ). You can get a RR454 card which has that BIOS already installed but it doesn't make any difference, it's the same hardware. And yes, your CPU will be performing the XOR calculations just like in software RAID.

If you need 320GB of space then clearly RAID10 is going to be more expensive than RAID5. I just think you'll find transferring 320GB of stuff onto a software RAID array extremely tedious. I ditched mine for 8 drives in RAID10.

If you don't have the extra cash (and who does?) try just getting the 1 extra hard drive now and setup a software RAID solution and see how it goes.

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[Codesmith]

I did some research and the cheap (<200) hardware raid cards are increadibly slow. Worse than software Raid.

And unfortunately one of my friends has just changed his mind about getting a 300GB SATA drive, which I was planning on using borrowing to hold my data while I create the RAID 5 array.

I do however have a 40 and a 45 laying arround, and there is a good chance I can borrow a 3rd 40 GB from a friend which will let me test out a software RAID 5 array.