Hardware RAID vs Software Disk Management...

[Caveman]

Do programs like Norton "Ghost" or "Fileback" take the place of a hardware RAID? If no, what exactly do (or don't) these programs do with repect to allowing data mirroring, which if I'm not mistaken is RAID 1, right?

Is a hardware RAID superior or inferior to what software can do?

 

[Matthias99]

Originally posted by: Caveman
Do programs like Norton "Ghost" or "Fileback" take the place of a hardware RAID? If no, what exactly do (or don't) these programs do with repect to allowing data mirroring, which if I'm not mistaken is RAID 1, right?

Is a hardware RAID superior or inferior to what software can do?

Uh... what? Why are you comparing imaging software to using RAID? They're completely different. 😕

Hardware and software RAID do the same thing functionally; a good hardware controller will have lower CPU load (especially for RAID5/6), and may improve performance (if it has a large amount of onboard cache and you use write-back caching).

 

[Woodie]

RAID=Redundant disks. If properly configured, then when/if a drive crashes, will have little/no impact on the rest of the computer. (doesn't crash, no data loss, etc...)
Imaging software: Take a snapshot of a disk/array at a particular point in time.

Hardware RAID > Software RAID. (Quality, stability, price)

 

[Caveman]

If Ghost and Fileback are just "snapshots"...

Then, what are some software RAID solutions? And... if they are inferior, why would anyone use them? Is it because:

a) Their hard drives are "too different" to be RAIDed? How similar do the drives have to be??

b) They don't want to get in their computer and start flopping jumpers around (they just want to do the "easy" software method)

 

[Matthias99]

Originally posted by: Caveman
If Ghost and Fileback are just "snapshots"...

Then, what are some software RAID solutions?

Any RAID controller that costs less than, oh, $250 or so is software-based. As are all onboard RAID controllers that I have ever seen. And then there's doing RAID purely in software, by having the OS split up the writes between the drives.

And... if they are inferior, why would anyone use them? Is it because:

a) Their hard drives are "too different" to be RAIDed? How similar do the drives have to be??

Well, they have to work on the same controller, obviously, and for most RAID levels they have to be the same size (or else the larger one is cut off and only some of the capacity is used).

Software RAID can do things like using both IDE and SATA/SCSI drives in one RAID setup (although you wouldn't usually want to do this, for performance reasons).

b) They don't want to get in their computer and start flopping jumpers around (they just want to do the "easy" software method)

It's not really any easier or harder, but it's usually cheaper. Like I said, you'll pay at least $200-250 for a hardware RAID controller, and the good ones with lots of onboard RAM (especially if they are SCSI controllers) can cost much more.

If you have CPU power to burn, a good software RAID implementation should work just as well as 'hardware' RAID. And for RAID0/1/01/10, the CPU overhead is pretty low.

 

[Caveman]

Good info. thanks... I thought all retail MoBos from about 3 years ago forward have RAID capability (via "built in" HD controller)...

I can't say I've ever seen a piece of hardware called a "controller" for sale but then again, I've never had a need to look prior to know...

Any recommended controllers for a simple IDE RAID?

I want redundancy, not speed striping... Redundant drives are RAID 1, right? (RAID zero is for speed?)

 

[Matthias99]

Originally posted by: Caveman
Good info. thanks... I thought all retail MoBos from about 3 years ago forward have RAID capability (via "built in" HD controller)...

Yes, but on consumer motherboards I've only ever seen software RAID implementations. It's basically just a regular disk controller with drivers that know how to do RAID.

I can't say I've ever seen a piece of hardware called a "controller" for sale but then again, I've never had a need to look prior to know...

Um... what else would you call the thing your hard drives plug into? 😕

Any recommended controllers for a simple IDE RAID?

I want redundancy, not speed striping... Redundant drives are RAID 1, right? (RAID zero is for speed?)

Frankly, the onboard stuff is usually fine unless you need high performance. However, if you are doing this because you don't want to lose data due to random drive failure, you are better off not using RAID, putting one drive in an external enclosure, and performing regular backups. RAID1 doesn't help you if you get a virus, or accidentally delete your files, or your OS installation/RAID controller gets hosed and starts randomly corrupting things, or your house burns down and the computer is totalled.

StorageReview has lots of good articles about different RAID levels and what they are and are not good for. RAID1 mirrors data onto two or more drives, keeping an identical copy of all the data on each drive.

 

[Caveman]

Um... what else would you call the thing your hard drives plug into? 😕

I call it "My MoBo Hard Drive Connector" 🙂

Frankly, the onboard stuff is usually fine unless you need high performance. However, if you are doing this because you don't want to lose data due to random drive failure, you are better off not using RAID, putting one drive in an external enclosure, and performing regular backups. RAID1 doesn't help you if you get a virus, or accidentally delete your files, or your OS installation/RAID controller gets hosed and starts randomly corrupting things, or your house burns down and the computer is totalled.

Maybe this is crazy, but here's what I'd planned (without knowing if it would work)...

2 HDDS, 1 200 GB Seagate Barracuda and 1 80GB Seagate Barracuda:

200 GB HD has 3 partitions: 30 GB for programs, 50 GB for data mirroring from other 80 GB drive, and 120 GB for other files that I'm not too worried about...

80 GB HD has 2 partitions: 30 GB space for mirror of 200 GB programs partition, and 50 GB for data storage.

Would this work?

Incidently, have you ever heard of a piece of disk management software called "Fileback"?

 

[cubby1223]

Originally posted by: Matthias99
Any RAID controller that costs less than, oh, $250 or so is software-based. As are all onboard RAID controllers that I have ever seen. And then there's doing RAID purely in software, by having the OS split up the writes between the drives.

Definately not true. The Promise & Adaptec hardware raid controllers start at ~$60.

$250 is about where you start seeing the addition of RAID 5 functionality.

And there were a couple select few motherboards that had a Promise chip with hardware raid, and I've got a new board on order that's got an Adaptec raid chip that I'll be trying out (although I purchased a $125 3ware raid controller as well that is planned on being the permanently used controller for the hardware RAID 1).

Originally posted by: Caveman
<snip>
Would this work?

No.

Originally posted by: Caveman
Is a hardware RAID superior or inferior to what software can do?

You won't see the disadvantages of software raid until you actually have something go wrong with the system - and then you'll understand exactly why hardware raid is by far the preferred method.

 

[RebateMonger]

Originally posted by: cubby1223
$250 is about where you start seeing the addition of RAID 5 functionality.

And when you see RAID 5 functionality, that's usually when you have a "hardware-based" RAID card. The $60 RAID controllers are considered to be "Software-based" RAID cards, as are the low-end RAID controllers built into many motherboards.

A software-based RAID card ISN'T the same thing as OS-based software RAID (as offered in Windows Server). It means there's no onboard CPU or memory dedicated to the RAID function. Software-based RAID using a card or chip has advantages over Windows OS-based RAID, such as the ability to reboot from Drive 1 when Drive 0 fails. Windows software RAID can't do that. And Windows-based RAID requires dynamic disks, which can complicate data recovery.

I have nothing against "software-RAID" cards. I use them on my own servers for RAID 1. But, the difference is where the RAID calculations take place. A "software-based" RAID card relies on the computer's CPU for its calculations. A "hardware-based" RAID card has a separate CPU onboard, along with memory, and it does all of its RAID control functions onboard the RAID card. The difference shows up when you try doing RAID 5, which is calculation-intensive. RAID 5 without an onboard CPU and memory is pretty slow.

 

[cubby1223]

Originally posted by: RebateMonger
And when you see RAID 5 functionality, that's usually when you have a "hardware-based" RAID card. The $60 RAID controllers are considered to be "Software-based" RAID cards, as are the low-end RAID controllers built into many motherboards.

All right, I give it to ya - the Promise cards are indeed software raid. My bad. Though I must say, of all the software raid controllers, the Promise is probably the most useful (and they do a decent job of hiding the fact that it is software raid).

But regardless, hardware raid can be had for far less than the $250 mark mentioned above, like this 3ware card I've purchased on many occasions:
http://www.newegg.com/Product/Product.asp?Item=N82E16816116030

 

[RebateMonger]

Yup. There are some $100-$200 hardware RAID cards.

I DO prefer using a separate RAID card, rather than using built-in chipset RAID. The problem with chipset RAID comes when you have to move your drives to a new motherboard. It's trivial with a RAID card: Just move the card and the drives together and it's done. But a RAID array created with a chipset-based controller normally can't be moved. You have to restore the data to a new drive array created on the new system.

 

[Caveman]

Thanks all... so...

If I have 2 HDDS, 1 200 GB Seagate Barracuda and 1 80GB Seagate Barracuda...

Aside from just a system backup, is there any way I can do any derivation of what's proposed below with software?

200 GB HD has 3 partitions: 30 GB for nominal storage of programs, 50 GB for data mirroring from other 80 GB drive (below), and 120 GB for other files that I'm not too worried about...

80 GB HD has 2 partitions: 30 GB space for mirror of 200 GB programs partition (above), and 50 GB for nominal data storage.

 

[NateSLC]

As far as I know, you can only set up whole drives in RAID, not partitions. If you set up a 200GB and an 80GB drive in RAID 1, you would end up with 1 usable 80GB drive.

 

[hhobbies]

Originally posted by: Caveman
Thanks all... so...

If I have 2 HDDS, 1 200 GB Seagate Barracuda and 1 80GB Seagate Barracuda...

Aside from just a system backup, is there any way I can do any derivation of what's proposed below with software?

200 GB HD has 3 partitions: 30 GB for nominal storage of programs, 50 GB for data mirroring from other 80 GB drive (below), and 120 GB for other files that I'm not too worried about...

80 GB HD has 2 partitions: 30 GB space for mirror of 200 GB programs partition (above), and 50 GB for nominal data storage.

Yes.

With dynamic disks.

Create the two partitions (30G, 50G) on the 80G drive and install an OS that supports Dynamic Disks on the 30G part.

Then create partitions (30G, 50G, 120G) on the 200G drive.

Then upgrade the both drives to a dynamic disk.

Select the 30G part in disk manager, and choose create mirror from context menu, select the other 30G part as the spare.

Do the same with the 50G part.

Probably not the cleanest setup, and certainly non-optimal for performance (like that matters anyhow), but will work.

The more difficult part might be recovering from a failure.

Thats a new lesson.

 

[hhobbies]

=)