Is There Differences Between ATA and SCSI for RAID Arrays?

[Blush]

So I've been reading on threads all over the place about setting up RAID before i make mine tonight and was just about to attempt to set the first one when i noticed in device manager that one of my HGST drives is SCSI while the others are ATA. Is this going to cause any issues?

http://s11.postimg.org/7hctl3uab/image.png

My plans are for possibly:
1 x 6TB RAID 1
1 x 4TB RAID 1

My Motherboard is an Asus X99 deluxe with these connections.

https://www.asus.com/websites/global/products/WodJPah7ECKFSsxv/img/hp/performance/speed-1.jpg
http://i62.tinypic.com/zspoh0.png

Are any of these connections better suited for creating a RAID 1? If so which ones and in what way?

 

[clarkjd]

Why on earth would you want a RAID1 array? It doubles your chances of losing ALL of your data, because if you lose one drive in the array, you've lost the array and the only recovery is to replace the failed drive, then restore your data from backup. Also in real world desktop type tasks there is not that much of a performance increase. RAID1 was designed to improve server performance for multiple users.

You are just playing with fire.

 

[USAFRet]

Why on earth would you want a RAID1 array? It doubles your chances of losing ALL of your data, because if you lose one drive in the array, you've lost the array and the only recovery is to replace the failed drive, then restore your data from backup. Also in real world desktop type tasks there is not that much of a performance increase. RAID1 was designed to improve server performance for multiple users.

You are just playing with fire.

You're thinking of RAID 0 - striped.
RAID1 is mirrored.

But I do question what the OP is actually trying to do.

"1 x 6TB RAID 1
1 x 4TB RAID 1"
?

It does not work like that.
6TB + 4TB + RAID1 = 4TB actual drive space.
You want 2 drives of the same size, otherwise you are simply throwing away drive space on the larger drive.

 

[geofelt]

I do not know why, but devices in the device manager seem to say scsi devices when they are really sata attached devices.
No modern motherboard uses ATA anymore.
In your bios, you should have an option for setting the sata mode. IDE, AHCI, or raid. AHCI is a subset of raid.

Raid-1 is mirroring; you need two identical devices.
It protects explicitly against a hardware failure of one drive.

Regardless, why are you looking for raid of any type?

The value of raid-1 and it's variants like raid-5 is that you can recover from a drive failure quickly. It is for servers that can not tolerate any interruption.
Modern hard drives have a advertised mean time to failure on the order of 500,000+ hours. That is something like 50 years. SSD's are similar.
With raid-1 you are protecting yourself from specifically a hard drive failure. Not from other failures such as viruses, operator error,
malware, raid controller failure fire, theft, etc.
For that, you need external backup. If you have external backup, and can tolerate some recovery time, you do not need raid-1

 

[clarkjd]

Why on earth would you want a RAID1 array? It doubles your chances of losing ALL of your data, because if you lose one drive in the array, you've lost the array and the only recovery is to replace the failed drive, then restore your data from backup. Also in real world desktop type tasks there is not that much of a performance increase. RAID1 was designed to improve server performance for multiple users.

You are just playing with fire.

You're thinking of RAID 0 - striped.
RAID1 is mirrored.

But I do question what the OP is actually trying to do.

"1 x 6TB RAID 1
1 x 4TB RAID 1"
?

It does not work like that.
6TB + 4TB + RAID1 = 4TB actual drive space.
You want 2 drives of the same size, otherwise you are simply throwing away drive space on the larger drive.

You are right. RAID0 doubles the chances of a failure for a small increase in performance. RAID1 doubles your data security(if a drive fails, you still have the other drive) and cuts your total storage virtually in half (and at double the cost).

 

[geofelt]

Raid-0 has been over hyped as a performance enhancer.
Sequential benchmarks do look wonderful, but the real world does not seem to deliver the indicated performance benefits for most
desktop users. The reason is, that sequential benchmarks are coded for maximum overlapped I/O rates.
It depends on reading a stripe of data simultaneously from each raid-0 member, and that is rarely what we do.
The OS does mostly small random reads and writes, so raid-0 is of little use there.
There are some apps that will benefit. They are characterized by reading large files in a sequential overlapped manner.

Here is a study using ssd devices in raid-0.
http://www.tomshardware.com/reviews/ssd-raid-benchmark,3485.html
Spoiler... no benefit at all.

 

[USAFRet]

Blush...what is the theoretical use for this RAID thing?
What are you actually trying to do, and with what equipment?

 

[Blush]

Blush...what is the theoretical use for this RAID thing?
What are you actually trying to do, and with what equipment?

It's mostly to try and aid in the prevention of losing data in the event that one of the HDD's fail. In which case I'd still have everything exactly as it was on the second drive. Mostly for files that are used in any Video and 3D productions i'm working on etc. Also, i have close to 3Tb of video/music/pictures i'd like to have in RAID as well purely to prevent losing any of it.

However, there seems to be a bit of a negative attitude between wanting to have a RAID configuration and only needing to backup the drive. Which I guess leaves me with another question:

What makes a backup more secure than a RAID when anything that can go wrong with HDD's in a RAID config can go wrong on a HDD with just a backup file on it? Or is that statement incorrect.

The main benefit as i see it is that a RAID is updated every time i make changes to the drive yet Backups i have to do manually in my own time which i'd rather not worry about.

In regards to your first comment about using a 4Tb and 6Tb in one RAID 1 configuration. What i meant was a single 4Tb RAID with 2 x 4Tb HDD's and another 6tb RAID 1 of 2 x 6TB.

Sorry for all the points of interest.

 

[Blush]

I do not know why, but devices in the device manager seem to say scsi devices when they are really sata attached devices.
No modern motherboard uses ATA anymore.
In your bios, you should have an option for setting the sata mode. IDE, AHCI, or raid. AHCI is a subset of raid.

Raid-1 is mirroring; you need two identical devices.
It protects explicitly against a hardware failure of one drive.

Regardless, why are you looking for raid of any type?

The value of raid-1 and it's variants like raid-5 is that you can recover from a drive failure quickly. It is for servers that can not tolerate any interruption.
Modern hard drives have a advertised mean time to failure on the order of 500,000+ hours. That is something like 50 years. SSD's are similar.
With raid-1 you are protecting yourself from specifically a hard drive failure. Not from other failures such as viruses, operator error,
malware, raid controller failure fire, theft, etc.
For that, you need external backup. If you have external backup, and can tolerate some recovery time, you do not need raid-1

Thanks heaps for the info and for staying on topic. I feel like that's really close to answering my question but just slightly off. So there isn't a difference between the two and if i wanted to RAID ATA and SCSI connected HDD's together that that is fine?

So i assume when people say that all you need to do is backup they mean on an external drive but is an external drive any safer than in internal one if that internal drive is only going to be used for storing back up files?

 

[USAFRet]

The standard statement of "RAID1 is not a backup." applies here.

It only helps in one specific fail mode...a dead drive.
It does not do anything for accidental deletions, corruption, or any of the other myriad ways you can lose data.

RAID 1 is great if you actually need 24/7 uninterrupted access. Like hosting a webstore, for instance. Downtime = lost sales. With a dead drive, the system can limp along on the other drive.
But any business that was running a RAID 1 also has a verified backup.

For your use, a simple file or folder copy function would almost certainly be better.
SyncBack Free does this easily, on a schedule. Set it up once, and leave it.

Alternately, you can use one of the current drive imaging applications, and set up a schedule for an incremental drive image.
Casper, or Macrium Reflect will do this.
Incremental is good, because you can go back to 3 days ago, before whatever weirdness happened.
With a RAID 1, there is no 'go back'. You simply have two drives with the same bad data.


With the above mentioned SyncBackFree, you can configure it to NOT delete from the target if the file on the source is deleted (by accident or on purpose). "oops, I accidentally deleted the folder containing 5 years of my kids pictures"
With a RAID1, that deletion simply happens on both drives at the same time. Poof, file gone.

 

[USAFRet]

So i assume when people say that all you need to do is backup they mean on an external drive but is an external drive any safer than in internal one if that internal drive is only going to be used for storing back up files?

I have my SyncBack set to copy selected folders to another internal drive every 12 hours, and to a whole other PC (the house server) every 24 hours.
That house server also does the same thing, to a USB external drive once a day.

In the unlikely event of a natural disaster and having to bug out, I just need to grab one of the laptops and snag that single external drive. This contains a copy of anything that absolutely cannot be recreated.
OS and applications I can reinstall on new hardware. I can't get back a pic of my grandson at age 2.