Moving a RAID to a new computer

[nemophoto]

I'm considering rebuilding my PC in the coming months with a new motherboard and quad core Intel chip. Currently, I have an Asus motherboard with a Opteron dual-core and I use a RAID 0 setup with the on-board SiI chipset.

My question is this: can the hard drive RAID setup simply be unplugged from one computer to the next, or is it like the old SCSI setups where one controller was not necessarily compatible with another? In the past, I've had no problem swapping out a regular drive setup (SATA or IDE) -- only required loading additional drivers for the new motherboard, but I've never transferred a RAID.

Thanks,

Nemo

[ARD]

Might work if you are not booting from the drive. You'll need to load in the RAID driver from the new mother board utilities disk which usually happens in the operating system environment.

[nemophoto]

Wouldn't work. My RAID (2 - 320GB drives = 640GB) is the C:, D:, E: and F: drives, so Windows needs to boot.

[Jonathan Wienke]

My question is this: can the hard drive RAID setup simply be unplugged from one computer to the next, or is it like the old SCSI setups where one controller was not necessarily compatible with another?

If you were using an Adaptec or some other PCI card RAID controller, you could simply unplug the card from one motherboard, insert it in the other motherboard, connect the drives to the same ports on the card, and install the driver for the card.

But if you're using the built-in RAID on the motherboard, you can pretty much forget about it working without copying all data off the array, transferring the drives, rebuilding the array with the new controller, and then re-loading the data to the array.

[fike]

I have tried this.  The answer is NO.

The hard drives will be recognized as a foreign drive and need to be reformatted in the to work in the new system.  The easiest way to address this situation is to make a backup to another drive and then move and rebuild the raid array on the new machine.

good luck.

P.S.  Unless you were fortunate enough to have formatted them as FAT instead of NTFS.

[Jonathan Wienke]

I have tried this.  The answer is NO.

That's not true if you have a PCI RAID card and transfer the card and all of the drives in exactly the same configuration. I've transferred an Adaptec RAID card and associated drives from one computer to another with the array formatted NTFS with no problems. But both the source and destination machines were running flavors of Windows 2000.

[fike]

That's not true if you have a PCI RAID card and transfer the card and all of the drives in exactly the same configuration. I've transferred an Adaptec RAID card and associated drives from one computer to another with the array formatted NTFS with no problems. But both the source and destination machines were running flavors of Windows 2000.
[a href=\"index.php?act=findpost&pid=171889\"][{POST_SNAPBACK}][/a]

Sounds like Adaptec is a better manufacturer because my Highpoint PCI Rocket-RAID card doesn't support this (according to the manufacturer).

[nemophoto]

Thanks for the suggestions. As I mentioned, my RAID is based on the Silicon Image chipset built into the motherboard, not a seperate RAID card. (Additionally, I DO have an SiI eSATA card in the computer.) Interestingly, in device manager, the drives come up as "SiImage SCSI Disk Device". This is the whole reason I've wondered if I could just plop the drives into another motherboard, and other than device drivers needed for the new MB, run with it. When I saw it listed as a "SCSI Disk Device", I started thinking of the old SCSI controller card incompatibility (at times) with other manufacturers SCSI controllers.

The BIG problem with simply doing a bachup and transfer to a new hard drive setup is that I've only just had the computer again after major problems with XP, and installed Vista from scratch. (Best move I've made in a while.) It's been a true mess reinstalling programs, especially ANYTHING stamped with "Adobe".

If this become a pain, I'll just stick with my setup for a while, and when it's too dog slow, grit my teeth and rebuild. I'm starting to regret setting up a RAID. It hasn't provided the significant performance increase I thought it would. I would have done better going with a different single drive, perhaps even a 10,000 rpm drive. At least I wouldn't have the migration headache I might be faced with.

[fike]

If this become a pain, I'll just stick with my setup for a while, and when it's too dog slow, grit my teeth and rebuild. I'm starting to regret setting up a RAID. It hasn't provided the significant performance increase I thought it would. I would have done better going with a different single drive, perhaps even a 10,000 rpm drive. At least I wouldn't have the migration headache I might be faced with.
[a href=\"index.php?act=findpost&pid=172281\"][{POST_SNAPBACK}][/a]

I recently got a 10,000 RPM Raptor for my boot drive.  This has been one of the biggest single performance improvements of anything I have ever upgraded (processor, memory, or video card).

Highly recommend the HD upgrade.

[JF3012]

Jonathan is right.

New onboard RAID will need to write signature on disk and will reformat them.

With cheap HD these days, i would suggest switching to RAID 1 if you use them to store pictures as RAID0 double the failure chance over single disk usage (either of them failing will result in a lost of data over both of them).

[Jonathan Wienke]

I prefer RAID5 with a 4-8 drive array. This offers good data efficiency (less parity overhead than RAID 1) while offering speed boost and drive failure protection.

[JF3012]

Raid5 have the advantage of reduced "lost disk" space, where you lose 1/n instead of 1/2.

Raid5 performances are usually slower then Raid1 as you have to "create" parity and write it too.  

Also, it don’t offer much protection over Raid1 if you don't have a hot spare (that would make the lost 2/n), as the 2nd disk failure will render both unusable if not fixed before.  A RAID adaptor crash would probably make Raid5 recovery impossible too as you wouldn’t be able to reconstruct data without rebuilding your raid on a similar adaptor.  

Raid1 advantage also include the instant backup, as you can bring one of your array disk offsite (I do it usually when i leave for extended period) as full data is accessible.  It also have faster rebuilt time.


I used to prefer Raid5 when a 32gb tower with 8 disk was $25K+.  Now, with 500 gb drive under 100$ i think its way more convenient to have a simple Raid1 array even if the TCO is slightly higher.

[Jonathan Wienke]

Raid5 performances are usually slower then Raid1 as you have to "create" parity and write it too.

For writing, yes, although newer controllers make this less of an issue. Reading from RAID5 is very fast with a decent controller.

Also, it don’t offer much protection over Raid1 if you don't have a hot spare (that would make the lost 2/n), as the 2nd disk failure will render both unusable if not fixed before.

If the RAID box has the hot-swappable drive bay design (drive is in a carrier easily removed and replaced) this is a non-issue. When you get an error, simply swap the bad drive and rebuild.

A RAID adaptor crash would probably make Raid5 recovery impossible too as you wouldn’t be able to reconstruct data without rebuilding your raid on a similar adaptor.

A drive controller failure will usually cause lost data, regardless of whether a RAID array or a single drive.

[JF3012]

Also, it don’t offer much protection over Raid1 if you don't have a hot spare (that would make the lost 2/n), as the 2nd disk failure will render both unusable if not fixed before..

If the RAID box has the hot-swappable drive bay design (drive is in a carrier easily removed and replaced) this is a non-issue. When you get an error, simply swap the bad drive and rebuild.

I was just trying to point out that RAID5 isn't safer if you dont have a hot spare with an auto-rebuilt settings.  Hot swap bay just make it easier to replace the failed drive.  RAID1 and RAID5 offer the exact same level of security if you happend to have an unused drive that you can use to rebuilt your array.  Actually RAID1 would be safer, as it rebuilt faster.

A drive controller failure will usually cause lost data, regardless of whether a RAID array or a single drive.

Even in the event of an adaptor failure, the full data would still be accessible on either RAID1 disks (if adaptor didn't corrupted any data).  

You could access data using drive as single or plug it using external case (USB or FireWire).

[marty m]

If you were using an Adaptec or some other PCI card RAID controller, you could simply unplug the card from one motherboard, insert it in the other motherboard, connect the drives to the same ports on the card, and install the driver for the card.

But if you're using the built-in RAID on the motherboard, you can pretty much forget about it working without copying all data off the array, transferring the drives, rebuilding the array with the new controller, and then re-loading the data to the array.
[a href=\"index.php?act=findpost&pid=171869\"][{POST_SNAPBACK}][/a]

Jonathan is absolutely correct.  Asus tech support will tell you the same thing, as will Adaptec.

There are four reasons to buy a separate RAID card such as Adaptec:

(1)  Buy a true hardware raid card.  It costs more money, but the processing is done on the card and not by the CPU.

Some Asus tech support staff will assert that their RAID is hardware based.  THAT IS FALSE and really competent Asus tech staffer will admit exactly that.  Almost all of the RAID systems on motherboards are at least partially software based, meaning that they off load the RAID processing to the CPU.

NOTE that Adaptec also makes software based RAID cards.  So be certain you are buying TRUE hardware based RAID.

(2)  As you have discovered, you can move a hardware RAID Adaptec card to a different PC.  That is not true with software RAID on a motherboard

But there is another important implication here.  Assume the motherboard fails.  When it fails, so does your entire RAID array.  If you are depending on RAID for your sole source of backup, well, you are screwed in the event of motherboard failure.  You just lost your RAID array as well.

That is not  the case with a RAID array using Adaptec.  You can simply take it out and move it to a new motherboard.

(3)  Vista Ultimate comes with a new encryption system called Bitlocker.  If you want to use Bitlocker, and want to use RAID, you MUST use TRUE hardware based raid such as more expensive Adaptec card.  Software motherboard RAID will cause Bitlocker to fail.

(4)  But here is the single biggest advantage of Adaptec hardware RAID.  I am running RAID with four 750 GB drives in a RAID 10 (1 + 0) configuration.  That gives me about 1.2 or 1.3 TB of storage space.

Now, assume I run out of space, and want to switch to RAID 5.  With Asus motherboard based RAID -- if it does RAID 5 -- I'm fairly sure you must wipe the drives and start over.  Switching to a different type of RAID will reformat or wipe the drives.

With Adaptec I can switch to RAID 5 on the fly and no reinstallation of the OS and software is necessary.  So I can automatically get about one additional terabyte of storage at anytime with no hassle.

That is a HUGE advantage of using true hardware based Adaptec RAID cards.