Hardware RAID vs Software RAID

LMiller7 said:

Many people rush into RAID without understanding it's purpose, what it is, and what it is not. Only later do they find that performance isn't what they expected, or they loose data they thought was protected.

Each type of RAID has it's advantages and disadvantages.
RAID 0 is about performance. It works by increasing transfer rate which is useful when doing serial access of large files. But typical usage in Windows (or any modern OS) tends toward random access to relatively small blocks of data spread over multiple files. In this case the drive spends most of it's time moving the heads and platter position to the data in question and relatively little time with data transfer. RAID won't do much good for this situation. There are legitimate uses for RAID 0 but not many.

The purpose of RAID 1 and RAID 5 is to protect access to your data, but not the data itself. They are not the same thing.

RAID 1 and RAID 5 provide redundancy so that if one drive fails access to your data continues as if nothing happened. This is an enormous advantage in a busy server where downtime is very disruptive to business activities and a major cost. Drive replacement can be deferred to a more convenient time, and with hot swap can be done without downtime at all. The main problem with RAID 1 is that you need 2 drives to provide the storage capacity of 1 and the cost is often hard to justify for workstation use. RAID 5 provides better storage efficiency, but you need at least 3 drives.

But no form of RAID ever devised can protect your data. RAID (except RAID 0) will provide protection from drive failure only, and even that cannot be relied on. In the event of a serious malware infection, accidental or malicious file deletion, other hardware failures, etc., all data could be lost.

To protect your data you need backups. Files of any importance need at least one backup copy while those of particular importance need 2 or more backup copies. Backup copies do fail and this often happens when you need them the most.

Thank you! That is an excellent explanation! I'm amazed at the number of experts who fail to understand that.

LMiller7 said:

Many people rush into RAID without understanding it's purpose, what it is, and what it is not. Only later do they find that performance isn't what they expected, or they loose data they thought was protected.

Each type of RAID has it's advantages and disadvantages.
RAID 0 is about performance. It works by increasing transfer rate which is useful when doing serial access of large files. But typical usage in Windows (or any modern OS) tends toward random access to relatively small blocks of data spread over multiple files. In this case the drive spends most of it's time moving the heads and platter position to the data in question and relatively little time with data transfer. RAID won't do much good for this situation. There are legitimate uses for RAID 0 but not many.

The purpose of RAID 1 and RAID 5 is to protect access to your data, but not the data itself. They are not the same thing.

RAID 1 and RAID 5 provide redundancy so that if one drive fails access to your data continues as if nothing happened. This is an enormous advantage in a busy server where downtime is very disruptive to business activities and a major cost. Drive replacement can be deferred to a more convenient time, and with hot swap can be done without downtime at all. The main problem with RAID 1 is that you need 2 drives to provide the storage capacity of 1 and the cost is often hard to justify for workstation use. RAID 5 provides better storage efficiency, but you need at least 3 drives.

But no form of RAID ever devised can protect your data. RAID (except RAID 0) will provide protection from drive failure only, and even that cannot be relied on. In the event of a serious malware infection, accidental or malicious file deletion, other hardware failures, etc., all data could be lost.

To protect your data you need backups. Files of any importance need at least one backup copy while those of particular importance need 2 or more backup copies. Backup copies do fail and this often happens when you need them the most.

Yeah, pretty superstitious eh?

So RAID 1 even though the files are normal and not split, you CANT move drives? Is it because there is something that only a RAID card can understand, hence the separate RAID mode in the BIOS?

Raid 5.

Because it provides redundancy, requires less drives than raid 0 and 10 (raid 0 efficiency is 1, where as raid 5 is 1/n - better). Although raid 10 has an efficiency of 2/n, I'm prepared to wear the risk of only one drive failing at one time.

Raid 6 is not cost effective for small installations, but would be better is an environment where drives are prone to failure. But for home, I use raid 5 on my server.

Hardware raid is better because it takes the load off the OS.

IMHO.

Tanya

You know what, should I repost this just to add RAID 5 and 6?

And post why you want to do this and where you want to do it.

With the price of today`s ss drives and hd drives (cheap) what`s the point in a raid setup in a home pc.

And why would you want to pull the drives to put in another pc.

Computer0304 said:

You know what, should I repost this just to add RAID 5 and 6?

AddRAM said:

And post why you want to do this and where you want to do it.

With the price of today`s ss drives and hd drives (cheap) what`s the point in a raid setup in a home pc.

And why would you want to pull the drives to put in another pc.

And add No Raid.

So I should? And I would want to pull it out in case the system does not boot so I can connect to another computer.

Computer0304 said:

You know what, should I repost this just to add RAID 5 and 6?

Don't do it just because I said Raid 5 - If I am one of the very few that uses it.

And No RAID?