Raid-1 Raid-10 Questions

Raid 1 only supports 2 disks, raid 0 you can add quite a few

Raid10 is 4 disks, as for failure it'sthe same as raid1, remove and let the controller rebuild.
It can handle 2 dropped/bad drives depending on which ones they are in the array.

If you are thinking of going raid do yourself a favor and get raid edition drives not only
because they are designed for raid but they are more robust and have better error correction.

Software raid does not matter but firmware/hardware it does help.

Unlike Intel, AMD does not offer their own raid, that is why they use 3rd party like Promise.
 
With software RAID/advanced FS you can get a RAID0 of several RAID1 mirrors. Triple mirrors are also possible.
 
ep0x73 said:
Raid 1 only supports 2 disks, raid 0 you can add quite a few

Raid10 is 4 disks, as for failure it'sthe same as raid1, remove and let the controller rebuild.
It can handle 2 dropped/bad drives depending on which ones they are in the array.

If you are thinking of going raid do yourself a favor and get raid edition drives not only
because they are designed for raid but they are more robust and have better error correction.

Software raid does not matter but firmware/hardware it does help.

Unlike Intel, AMD does not offer their own raid, that is why they use 3rd party like Promise.
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Wrong. RAID1 is not limited to a single disk and RAID10 is not 4 disks, that's just the minimum. Enterprise drives are also a complete waste in home-use scenarios that don't involve parity.
 
Blue Fox said:
Wrong. RAID1 is not limited to a single disk and RAID10 is not 4 disks, that's just the minimum. Enterprise drives are also a complete waste in home-use scenarios that don't involve parity.
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Maybe he missed something, he was talking about error correction based in hardware and all I see is that raid edition drives dont keep retrying to read the same sector and just sends back an error so it don't cause the array to drop the drive. I was checking like the WD drives and their SE and RE drives are both 7200 RPM but one costs less and max speed is 171MB while the other for $25 more gives 225MB. In the good old days when they used different components for home and enterprise drives. I know Seagate starts getting cheap once they debugged the drive but not sure if they keep the higher quality components in their enterprise drives. The thing is, the cost difference these days are only a few $$'s and as we see from HGST and Toshiba drives which are close enough in cost to the others and who uses the same components in both versions.. 2 Decades ago enterprise drives cost triple the consumer versions but it seems using the same components and giving an extended warranty is a lot more cost effective for them than maintaining 2 product lines.

Oh yea "NOW" there can be differences in consumer and enterprise drives where companies like seagate and WDC will change,mix and match components in consumer drives which causes problems if you replace one of the drives. Buying the same model does not guarantee the drive with the same spec. So thats also something to keep in mind, OR you can buy extra drives to store as spares just in case. seagate might be doing this on purpose since now everyone uses consumer drives in data centers. Even facebook and google etc.. They dont want companies to use these cheap drives and getting away with it. And they wont even send the same drive back for replacement. Only the capacity will match.
 
I never said raid1 was limited to a single disk, you have two disks in a mirror and you can have a hot spare.

I never seen raid10 with more then 4 to add to the array.

raid0 and 5 you can add more by design.

Yes enterprise drives have better error control and are simply built to be more robust for 24/7 workload.

We are talking desktop here, not massive rack systems that do not have limitations.
 
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ep0x73 said:
Raid 1 only supports 2 disks, raid 0 you can add quite a few
Click to expand...

No Raid 1 supports as many HDD's as you like

Raid 1 is a Mirror ---- eg 2nd drive is a mirror copy of the 1st drive

no reason why you cant have a 10 way or more mirror set if you like.

for shits and giggles for example lets make a 3 way mirror....

then once all drives are synced, you can eject the 3rd drive from the mirror set to still leave you with a 2 way mirror for (safety)

then pop the 3rd drive on the shelf .... which is now your backup of the mirror;)

any problems....even if both drives in the 2 way mirror die. pop the 3rd drive off the shelf back in .... boot up and your up and running (in degraded mode.).....then simply grab another disk and pop it in...re sync the mirror and you back in safe land.

.
 
ep0x73 said:
We are talking desktop here, not massive rack systems that do not have limitations.
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Yes that is correct, sorry I should have clarified. My intentions is more for a centralized storage PC; not a true home server. Someplace to secure my growing collection of family videos and digital photos. That plus an offsite backup.

The machine will probably spend most of its time in some low power state.

At present WD are my preferred drive. Is a standard Red drive that much better than a green? I ask because now I see Red Pro drives.
 
ZFS in fact by design supports more than 2-way mirrors. The fact that you have never seen raid10 with more than 4 drives is not a definitive statement of fact (I have 8 drives in my raid10...)
 
ep0x73 said:
I never said raid1 was limited to a single disk, you have two disks in a mirror and you can have a hot spare.

I never seen raid10 with more then 4 to add to the array.

raid0 and 5 you can add more by design.

Yes enterprise drives have better error control and are simply built to be more robust for 24/7 workload.

We are talking desktop here, not massive rack systems that do not have limitations.
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3-way mirror is possible with all 3 drives active, not hot spare.

And you can have as many disks in a 10 as you like. I am currently running 14 disks in a 10 array.
 
ep0x73 said:
Raid 1 only supports 2 disks
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Not quite correct. You can put as many disks as you want into a RAID1 setup. It's just more redundant copies.

Realistically, it's a nearly pointless waste of disk space.

The notion that you can only have two active drives in a RAID1 array is a fiction. Or, if encountered IRL, due to a shoddily implemented controller.
 
The most flexible RAID 10 implementation I have seen is in linux software RAID (mdadm). It works with ANY number of drives: 2, 3, 4, 5, ... and has three choices for configuration (near, far, offset).

Of course it is a non-standard layout for 2 or odd numbers of drives, but it is useful nonetheless. Functionally, RAID 10 near configuration with two drives is the same as a RAID 1 of two drives, but two drive RAID 10 with far or offset configuration is distinct and useful.
 
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Don't forget RAID is a generic term, like fridge. It doesn't tell you anything about implementation. I'm sure plenty RAID controllers, and not just entry level ones, won't do 3 way mirrors.
 
m1abram said:
3-way mirror is possible with all 3 drives active, not hot spare.

And you can have as many disks in a 10 as you like. I am currently running 14 disks in a 10 array.
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You sure are not using Intel then with only 6 ports, if you have 14 ports you are beyond the typical home computer.

To clarify we are talking home computers using built in Intel or AMD which have limitations, not LSI cards or rack servers.

As for a 3 way mirror, I've popped a drive into my raid1 array, let it copy and then yanked it for a full copy spare.

There was also no mention of raid through linux or other systems so the assumption would be windows and it's limitations.
 
ep0x73 said:
There was also no mention of raid through linux or other systems so the assumption would be windows and it's limitations.
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Huh? The OP did not mention any OS or platform at all. So the question was about RAID in general, and people gave examples of some specific implementations. It makes no sense to limit the discussion to Windows.
 
MichiganPC said:
Yes that is correct, sorry I should have clarified. My intentions is more for a centralized storage PC; not a true home server. Someplace to secure my growing collection of family videos and digital photos. That plus an offsite backup.

The machine will probably spend most of its time in some low power state.

At present WD are my preferred drive. Is a standard Red drive that much better than a green? I ask because now I see Red Pro drives.
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and Win7 OS.
 
At this point you will be limited to the ability of your board and it's controller.

You could look into a external USB like the WD mybook duo that go up to 6TB [2x6 set to raid1] for your
expanding collection but it's not cheap at $600
 
ep0x73 said:
You sure are not using Intel then with only 6 ports, if you have 14 ports you are beyond the typical home computer.

To clarify we are talking home computers using built in Intel or AMD which have limitations, not LSI cards or rack servers.

As for a 3 way mirror, I've popped a drive into my raid1 array, let it copy and then yanked it for a full copy spare.

There was also no mention of raid through linux or other systems so the assumption would be windows and it's limitations.
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Running two SAS 9207-9i cards with dual E5 CPU and 96GB RAM so yeah not really a home computer.
 
One last question;

Are raid controllers like memory; it dumbs down to the slowest speed modules; or drives in this case?

If I setup for Raid-1 on the Sata3 (6Gb/s) controller and plug in a Sata2 drive same controller but non-raid configured port does the Raid-1 run at 6 or 3 Gb/s?
 
If I setup for Raid-1 on the Sata3 (6Gb/s) controller and plug in a Sata2 drive same controller but non-raid configured port does the Raid-1 run at 6 or 3 Gb/s?
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If you are talking about hard drives it does not really matter. The fastest SATA hard drive transfers data from the fastest part of the disk at around 200 MB/s so the question on if it will communicate at 300MB/s or 600 MB/s does not really make that much of a difference. These speeds only benefit SSDs or if you are using an expander.


Now to answer the question the SATA II drive will run at SATA II speed with the raid at SATA III speeds.
 
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I'm presently up and running with my Raid-1 setup. I still have some concerns though.

I feel my struggles have to do with the GigaByte board and implementation of AMD's SB850 controller.

No matter what I tried I could not get the OS (Win7-64) to see the raid drives even though Device Manager and Drive Manager saw them. The fix was to load the old AMD RaidXpert 32-bit utility. Even though the raid was setup already via the raid BIOS I had to repeat the setup under RaidXpert only then would the OS see the raid-1 array.

I'm concerned about the reliably of the 32-bit utility. Is there a 64-bit version or alternative utility from GigaByte?
 
This is a consumer software raid solution and I have never seen those as being all that great. You probably better off with no RAID than that for stability. If you want RAID1 level storage and do not want to get a proper raid controller then I would just do it in the OS and leave those software based raid controllers alone.
 
MichiganPC said:
I'm presently up and running with my Raid-1 setup. I still have some concerns though.

I feel my struggles have to do with the GigaByte board and implementation of AMD's SB850 controller.

No matter what I tried I could not get the OS (Win7-64) to see the raid drives even though Device Manager and Drive Manager saw them. The fix was to load the old AMD RaidXpert 32-bit utility. Even though the raid was setup already via the raid BIOS I had to repeat the setup under RaidXpert only then would the OS see the raid-1 array.

I'm concerned about the reliably of the 32-bit utility. Is there a 64-bit version or alternative utility from GigaByte?
Click to expand...

That seems strange. I was running RAID10 on my old AMD machine using the on-board chipset on a Gigabyte motherboard and Windows 7 had no issues seeing the array. It was set up as a boot volume and I had 320GB of space available using 4 ancient 160GB consumer drives for shits and giggles. It was using the 78LMT-USB3 that came free with the last FX-6300 that I bought at Microcenter. Apparently that board had the SB710 chipset though.
 
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