Understanding RAID and SATA: A Comparison for Optimal Storage Solutions

[Saint]

Can you help explain what are they?
Which one is better?

 

[dduardo]

Raid is used for hard drive redundancy. Striping is used to make multiple harddrive look like one big one. Mirroring allows the same data to be written to multiple drives incase one goes bad.

SATA is a bus that supercedes the old ATA standard that most computers use. It is the system used to transfer bits to and from hard drives, floppies and cdroms.

 

[Anttech]

RAID = redundant array of inexpensive disks...RAID has different configs
(ie RAID0 = mirrored, RAID1 = Stiped, RAID5 = stiped with parity)

SATA = serial ATA a means of access a HD... old ATA standard as dduardo says...

You cannot compare RAID and SATA as you could have a 2 SATA HD with a software RAID running...

RAID is a way to make your HD's more redundant and SATA is a standard for access (if you may) your HD... Like comparing apples and pears

 

[Linchpin]

RAID = redundant array of inexpensive disks...RAID has different configs
(ie RAID0 = mirrored, RAID1 = Stiped, RAID5 = stiped with parity)

SATA = serial ATA a means of access a HD... old ATA standard as dduardo says...

You cannot compare RAID and SATA as you could have a 2 SATA HD with a software RAID running...

RAID is a way to make your HD's more redundant and SATA is a standard for access (if you may) your HD... Like comparing apples and pears

Correction, RAID-0 is a striped array and RAID-1 mirrored. And relatively speaking RAID-0 isn't really true RAID since there is no mirroring, meaning no redundancy.

And on another note with the introduction of the SATA interface, the older parrallel interface may also be referred to as PATA.

 

[Anttech]

wopps my bad :-)

And yep Raid-0 is an anomaly

 

[Artman]

RAID 0 should not be used where data retention and accuracy is critical because the failure of any of the drives will lose all of the data in that array (the data is split over several drives in RAID 0). As everyone has been saying, there is no redundancy with RAID 0, however, it can be faster than other forms of RAID. For gaming or video editing, high bandwidth low critical data, it can split the task of input/output (two of the slower processes a computer performs) thus cutting the time required to load parts of games, manipulate large video clips, etc.

 

[Linchpin]

Yes it definitely speeds up read/write performance in disk access. I have two 80GB drives in a RAID-0 array with a 16k stripe and cluster size and it zooms along compared to just having one drive operating.

 

[Artman]

My knowledge of RAID is limited and I have very little SATA knowledge, so if I'm wrong about any of this, let me know.

I don't think anyone mentioned yet what a basic RAID setup is like. You need a RAID controller, either on your motherboard or a card, you need multiple Hard drives of the same size and speed, you can't put a 20 Gig 100 ATA running at 5600 RPM with a 60 Gig 133 ATA running at 7200 RPM, they need to match in specs.

I'm not sure what else, anyone else have any input on a basic RAID system? How many drives maximum, how is it wired, etc?

 

[Anttech]

You need a RAID controller, either on your motherboard or a card, you need multiple Hard drives of the same size and speed

Actually this is not 100% true, you do not need hardware to do RAID, you can do software RAID (Windows 2k/2k3 Server does this out of the box) the Disks do not have to be the same size. If you want to mirror disks, the disk that you are mirroring to need to be at least the same size as the master disk but can be bigger. Same as stripping I beileve.

 

[Artman]

Actually this is not 100% true, you do not need hardware to do RAID, you can do software RAID (Windows 2k/2k3 Server does this out of the box) the Disks do not have to be the same size. If you want to mirror disks, the disk that you are mirroring to need to be at least the same size as the master disk but can be bigger. Same as stripping I beileve.

Thanks Anttech.

You lose the difference in size when you do this, leaving you only use of the mirrored size, right?

Also, do the Disk speeds still have to match?

 

[Anttech]

yeh you loose the difference...

I am unsure about speed... I cannot think of any reason why the disks would need to be the same speed, tho. But I may be wrong! I will have a look and post what I find :-D

 

[graphic7]

I think the disk speeds would be irrelevant. I've run raid arrays before on IDE and SCSI drives. The only effect varying disk speeds *should* have would be a decreased performance, which won't inhibit you from running RAID (referring to Raid-0 here).

Raid-0 is typicaly faster than any of the other RAID modes, because of the absence of redundancy features.

You do have to keep a few things in mind if you want a decent (performance in mind) raid array. Make sure you have a decent IDE or SCSI controller. If the controller doesn't support the speeds of your hard drives, then you're going to have a performance problem. You also have to keep in mind (varying on the size of the hard drives, the speed of the hard drives and the controller(s)) the chunk size you want. Chunk size is a variable of how much data a chunk can carry. These chunks are the minimum and maximum of data that can be wrote or read at a time. Typically, a good chunksize is about 1mb. With hard drives getting faster and larger, you might want to start looking at 2mb.