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Very specific questions on RAID 0 and JBOD

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July 2, 2009 5:54:28 PM

I have a GA-MA69G-S3H motherboard which has one controller with 4 sata ports and also supports RAID 0,1 and JBOD on the same controller.

I have two identical hard drives on RAID 0 mode on one array.
I also have two more HDD's which are different in size which i want to use independently of RAID.
However, the motherboard only allows me to use them by enabling them as JBOD through the RAID controller as a different array (or 2 different arrays, which is how I set them up).
If I don''t set them up as JBOD, Windows XP (or linux) just doesn't see them.

1) Is there any way to just use them as independent disks without having them as JBOD and still use the first 2 drives as Raid 0?
2) In a case that I want to change mboard in the future, can I just take the 2 JBOD drives and use them at the new mboard as is without any data loss?
3) Is there any way to read the temperature of the drives in the RAID Array?

thanks
a b V Motherboard
a c 127 G Storage
July 2, 2009 8:30:06 PM

1) only if you connect them to a non-RAID controller; else you have to setup JBODs like you said. Some motherboards have chipsets that can both be RAID (ports 1 through 4) and seperately AHCI for cdrom/plain hdd on ports 5-6. These often have different colours on the motherboard. Some motherboards also have a seperate add-on controller on the motherboard, supplying additional SATA ports because the chipset doesn't supply enough.

2) No, normally you cannot migrate RAIDs (even JBODs since they use the same configuration mechanic) to other controllers or RAID-enabled chipsets. Only if you're upgrading from the same brand. So if you upgrade from ICH9R to a ICH9R or ICH10R chipset you can bring along your RAID and it should work fine, but not to any other brand.

However, you can just re-create the JBOD for seperate disks. This can't go wrong unless the RAID engine stores meta-data in a different location on the disk. Virtually all RAID systems store all configuration ("meta data") in the last sector (512 bytes) on each harddrive that is a member of a RAID-array (or JBOD). So in the case of JBODs, you should be able to re-create it on your new motherboard and use it without data-loss. No guarantees here though, but it *should* work.

3) only if the RAID engine supports it, called SMART passthrough. Often you need to use the vendor utility in order to read the SMART values; so its a vendor specific data interface. I've only seen this in hardware RAID; not in any chipset RAID though i haven't personally used or studied Intel chipset drivers so i wouldn't know in this case.

One piece of advice, think about data you never want to loose, because its too important. Your documents, your original digital photos, memories, letters, whatever.. often its not even so large. But please make a good backup, at least for this kind of irreplaceable data!
July 3, 2009 7:29:22 AM

Hmm.
About point number 2):
This is very worrying! What if I buy a new non RAID motherboard in the future?
I will not be able to use my current hard drives at all without losing the data first?

I will try today to simply remove one of the JBOD HDD's and attach it to a 2nd computer I have at home (which uses a Nforce4 chipset) to a normal non RAID sata port and see if it will be recognized with all it's data.

If it's not, it means that basically when I upgrade to a new motherboard I will probably be forced to format all my HDD's!


One more question.
If at my current motherboard I simply disable RAID through the BIOS, I will not be able to use the JBOD's? (the OS is installed on one of them).

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July 3, 2009 11:57:52 AM

You are absolutely right.
I have tried connecting one of the JBOD's to my 2nd PC and it can't recognize it.
I can only see it through it's RAID BIOS (so I would have to rebuild as JBOD and this might or might not corrupt the data as it's an older controller and probably by a different company).
I can't believe all this BS with Raid!!!

I will look online for a normal non raid SATA PCI expansion card so that I can transfer all my data to that controller one drive at a time so that when I do upgrade to a new motherboard I can still use all the hard drives and rid of RAID alltogether and probably never use RAID again!

thanks for the very good advice.

a b V Motherboard
a b G Storage
July 3, 2009 12:05:29 PM

brainii1 said:
Hmm.
About point number 2):
This is very worrying! What if I buy a new non RAID motherboard in the future?
I will not be able to use my current hard drives at all without losing the data first?

RAID 0 splits the data (stripes it) across the 2 drives. If you take 2 drives out of RAID 0, no the data cannot be read. It is basically unrecoverable

I will try today to simply remove one of the JBOD HDD's and attach it to a 2nd computer I have at home (which uses a Nforce4 chipset) to a normal non RAID sata port and see if it will be recognized with all it's data.

This may work, as JBOD is really just drive spanning. However, moving a RAID volume, whether it be an actual form of RAID, or JBOD, to a different controller is extremely risky. They are NOT for the most part, cross-compatable

If it's not, it means that basically when I upgrade to a new motherboard I will probably be forced to format all my HDD's!

If the controller is different, yes, most likely you will lose everthing


One more question.
If at my current motherboard I simply disable RAID through the BIOS, I will not be able to use the JBOD's? (the OS is installed on one of them).
July 3, 2009 12:46:48 PM

I just ordered a cheapo 6 Eur sata PCI card from Ebay.
Luckily one of my JBOD drives is 1 TB and is new so very little data on it, the other 2 drives are 200GB and one is 300GB.
I will move all the data from the 1TB to the others, then connect it to the PCI sata card, then copy all data from the other 3 drives to the 1TB, then format the 3 drives, disable RAID and use them as standalone sata's - non RAID and finally copy everything from the 1TB back to the others.
That should do it!
Phew!
RAID SUCKS! I mean what if the motherboard is somehow damaged or u want to switch mboards?
U just lose everything!
a b V Motherboard
a b G Storage
July 4, 2009 1:50:39 PM

That is only 1 reason out of many that RAID is not a good idea for a home PC.
I used to run RAID, and swear by it years ago when drives were smaller and slow.
With modern fast drives, there is no real benefit, and no need for it. It has become more of a personal preference of how you want to store your data.

Oh, and I just have to say this, putting your OS on a JBOD array, bad, bad idea.
Just put your OS on 1 fast drive, and maybe put 2 into RAID 0 for your applications or storage, and then put a large 3rd drive in to back up to, in case your RAID array fails, which it will at some point in time for some reason. You can bank on it.
July 4, 2009 7:44:39 PM

I totally agree with you.
However, my stupid motherboard doesn't support some RAID and some standalone drives (most mboards don't support this I think).
It's either all RAID or all standalone.
This will be changed however when my cheapo SATA PCI card arrives.
July 29, 2009 12:31:57 PM

I'm in the process of copying everything back.
I have a new question.
In my BIOS, for SATA controller I also have the AHCI option.
Now my understanding is that this allows hard drives to be faster by enabling native queuing but it also needs drivers for Windows XP.

My question is: if I enable AHCI and it's drivers, will it be possible to remove one of the hard drives and install it in a different motherboard/system without formatting it?

thanks
a b V Motherboard
a c 127 G Storage
July 29, 2009 10:08:36 PM

Just to note: linux/bsd can read the metadata stored by onboard "fake RAID" controllers (JMicron/Silicon Image/Intel/nVidia/AMD/Promise) and apply software RAID according to this configuration data (raid level, disk order, stripesize and - not often used - offset). So portability is possible, and data recovery is also possible by using linux/BSD software RAID. Without even writing to the device. Even RAID5s could be recovered this way.
a b V Motherboard
a c 127 G Storage
July 29, 2009 10:11:43 PM

Regarding your last question:

Yes using AHCI will make it a plain disk so any computer should be able to access the information. AHCI only requires drivers in Windows XP as XP doesn't offer native AHCI support. Vista and later do this without requiring additional drivers, as do Linux/BSD.
!