Hardware vs. Software RAID

[PaperclipGod]

So, my (limited) understanding is that hardware RAID is usually only necessary when you need reliable, fast storage... however, if the RAID card dies, you lose all the data on the array. Or is that wrong, and can you recover the array by installing the drives into a new RAID card (same or different model?)?

With software RAID, the CPU must handle the RAID overhead, decreasing performance... but it's a safer choice because there's no RAID card to die, and the software controller is easily reinstalled if there's a problem.

Is that about right, or did I just show everyone what a newb I am? :/

I realize that RAID itself should not be relied upon as the sole "backup"; however, as a piece of the backup system, I'm wondering which would be best to go with.

 

[Blain]

MBs have "software" RAID controller onboard...
For the most part, "hardware" RAID cards are more reliable than MBs these days.

 

[jamesbond007]

I have heard of successful MB-based software RAID migrations from one board to the next, but the controllers were still the same. (Think Promise, Highpoint, Silicon Image, etc)

How much data are you looking to store? A cheaper software-based RAID card is very affordable and at that rate, you can just buy two in case one dies. Hook the disks up to the other controller, configure it in the same fashion, and you *SHOULD* be ready to rock.

Some hardware RAID cards can be slower or operate slower if you don't have a BBU (Battery Backup Unit) attached. By default, my 3Ware Escalade was set to have write-caching disabled, so my throughputs were about 3-8MB/sec, depending on what I was writing. Enabling WC allowed me to achieve a much higher speed that is acceptable, but it warned me that if the system lost power during a write, data could be lost. I have a big UPS hooked up to my servers, so I'm not too worried. Plus, I'm not running a data center, so I don't really care too much about it. The big advantage of a dedicated hardware/software card is you can take it from one computer and throw it into another without problems. It's a little tougher to do so when the controller is soldered to the mainboard.

Good luck,
~Travis

 

[Madwand1]

Originally posted by: PaperclipGod
Is that about right, or did I just show everyone what a newb I am? :/

I realize that RAID itself should not be relied upon as the sole "backup"; however, as a piece of the backup system, I'm wondering which would be best to go with.

No, it isn't about right, because reality is a lot more complex than artificial "software" vs. "hardware" distinctions. RAID is not a standard, so every implementation has its own quirks, and if you're going to make specific choices, it's better to analyze them instead of broad theoretical "hardware" and "software" distinctions.

Good job recognizing that RAID is not a backup. Also recognize that if you have a real backup, while the reliability of the primary RAID still matters, the difficulties and concerns are reduced.

 

[JackMDS]

The whole RAID issue when it comes to regular computers and peer-to -peer network as blown out of proportion, and few of the major reason that somewhat where holding in the past are not an issue any more (like speed, and size of storage).

Unless some one has a very specific reason for a special system that needs real RAID, it time to move On and find something else as a symbol of Geek Coolness.

 

[Crusty]

Originally posted by: Blain
MBs have "software" RAID controller onboard...
For the most part, "hardware" RAID cards are more reliable than MBs these days.

That's considered fakeraid and not really software raid. Software raid works without any special disk controllers, think along the lines of WHS built in raid, and mdadm for Linux that offers full software raid support(and it's fast too!). In fact, you can even mix and match PATA + SATA drives in mdadm if you please.

With mdadm on Linux you can migrate the drives from computer to computer easily without worry about having the same disk controller.

 

[Blain]

Originally posted by: JackMDS
The whole RAID issue when it comes to regular computers and peer-to -peer network as blown out of proportion,
...time to move On and find something else as a symbol of Geek Coolness.

But Jack, we've been down the water cooling, CCF light, panel window, blow-hole roads!
"RAID" has cycled back up to the top. :laugh:

 

[Bill Brasky]

I wouldn't recommend setting up a raid using a controller integrated into the motherboard. My buddies old mobo just died and he's having a terrible time getting his data back. If you must setup a raid, please make sure you can move it to another system when your motherboard fails or after an upgrade.

 

[H Allen]

Glad I found this link. My system is raided from the mobo's SB600 and it's not that good for performance. I'm thinking of doing some major upgrades. Changing to a Highpoint Rocketraid card would be one. I like a 3510 or 3520. Any comments?

 

[yhelothar]

I ran RAID0 twice, in which it went corrupt on both occasions within 2-3 yrs. I was able to recover all my data back in both occasions, however, with either chkdsk or data recovery software.

 

[JackMDS]

Originally posted by: Crusty Software raid works without any special disk controllers, think along the lines of WHS built in raid,

Indeed.

This application (MirrorFolder) can make any computer work along the line of WHS.

It is a Sync program with a twist, it does real time Sync.

http://www.techsoftpl.com/backup/index.php

 

[OPaul]

Originally posted by: PaperclipGod
..however, if the RAID card dies, you lose all the data on the array. Or is that wrong, and can you recover the array by installing the drives into a new RAID card (same or different model?)?

Array data can be imported between RAID cards, at least with ServerRAID adapters by LSI.

 

[PaperclipGod]

Originally posted by: Madwand1

Originally posted by: PaperclipGod
Is that about right, or did I just show everyone what a newb I am? :/

I realize that RAID itself should not be relied upon as the sole "backup"; however, as a piece of the backup system, I'm wondering which would be best to go with.

No, it isn't about right, because reality is a lot more complex than artificial "software" vs. "hardware" distinctions. RAID is not a standard, so every implementation has its own quirks, and if you're going to make specific choices, it's better to analyze them instead of broad theoretical "hardware" and "software" distinctions.

Good job recognizing that RAID is not a backup. Also recognize that if you have a real backup, while the reliability of the primary RAID still matters, the difficulties and concerns are reduced.

Well, I appreciate you telling me I'm wrong, but I was hoping to get some advice as well. I admitted in my first post that I'm not sure if my understanding is correct or not. If it's not, could you please expand on what properties of RAID I should be analyzing? Or perhaps a general guideline for what environment the various types of RAID are best suited for? Telling me I'm wrong without giving me any advice comes off as a little rude, even if that wasn't your intention. :/

 

[PaperclipGod]

Originally posted by: OPaul

Originally posted by: PaperclipGod
..however, if the RAID card dies, you lose all the data on the array. Or is that wrong, and can you recover the array by installing the drives into a new RAID card (same or different model?)?

Array data can be imported between RAID cards, at least with ServerRAID adapters by LSI.

Excellent, thanks for responding to that question!

 

[Madwand1]

Originally posted by: PaperclipGod
Well, I appreciate you telling me I'm wrong, but I was hoping to get some advice as well. I admitted in my first post that I'm not sure if my understanding is correct or not. If it's not, could you please expand on what properties of RAID I should be analyzing? Or perhaps a general guideline for what environment the various types of RAID are best suited for? Telling me I'm wrong without giving me any advice comes off as a little rude, even if that wasn't your intention. :/

Sorry, I didn't mean to be rude, and I thought I did give some indication on what was wrong and implicit advice on the direction to take -- to not wander about over-simplistic theories about "hardware" vs. "software", etc., but rather identifying some real candidates that you might be able to buy and setup, and then comparing one verses the other.

You're asking about a very broad area, and asking very broadly. I'm sorry, but it's just not possible or worthwhile to give a meaningful analysis about every possible configuration. You can look for such guides that already exist, but they also tend to be wrong at one point or many, just because, as I said, reality is complex and doesn't lend it self to much simplification.

If we're to give you advice, help us out by giving us your context information -- such as the intended usage, originality / importance of data, budget, budget and scope of backup, OS, space and expansion requirements, motherboard, network, performance requirements, and anything else you think might be particularly relevant to your case. This forum even has a sticky about providing such information. The more you put into it, the more you'll get out of it.

Cheers.