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Raid setup with miss matched drives

Hello,

I have a 4tb HD from when I first got my computer and recently ripped apart the enclosure of my 8tb external HD as I purchased a NAS (got specific NAS drives for it).

So my question is on my main rig if I were to place the 8tb and 4tb and were to put them into Raid 0 for the gained speed, I understand it would be a 4tb, but am I able to access that extra 4tb on the 8tb drive as a new partition? or does it completely make it unusable/non visible?

 

Thank you,

Mink

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4 minutes ago, UnlinkedMink said:

Hello,

I have a 4tb HD from when I first got my computer and recently ripped apart the enclosure of my 8tb external HD as I purchased a NAS (got specific NAS drives for it).

So my question is on my main rig if I were to place the 8tb and 4tb and were to put them into Raid 0 for the gained speed, I understand it would be a 4tb, but am I able to access that extra 4tb on the 8tb drive as a new partition? or does it completely make it unusable/non visible?

 

Thank you,

Mink

When you make RAID array your OS will see both drives as one drive (in other words it doesn't see the drive at all it will just see the array) so the extra 4GB is lost to the void until you remove the raid.

 

Also remember if the drives have different read/write speeds the faster drive will operate at the speed of the slower drive, this also goes for cache and RPM.

So if one drive has 64mb cache and 5200rpm and the other have 32mb cache and 7200rpm they will both operate with 32mb cache and 5200rpm.

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I would advocate against doing this. You won't have access to the other 4TB and you're more likely to see hurt performance than anything.

 

If you really want to use them as one logical volume you can look into what's called a Spanned Disk. This doesn't do anything for performance and it does nothing for fault tolerance (but neither does RAID0) but it would allow you access to the full 12TB. Filling it up will likely degrade performance as well so be wary of that.

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2 hours ago, aDoomGuy said:

When you make RAID array your OS will see both drives as one drive (in other words it doesn't see the drive at all it will just see the array) so the extra 4GB is lost to the void until you remove the raid.

 

Also remember if the drives have different read/write speeds the faster drive will operate at the speed of the slower drive, this also goes for cache and RPM.

So if one drive has 64mb cache and 5200rpm and the other have 32mb cache and 7200rpm they will both operate with 32mb cache and 5200rpm.

Thank you, definitely will not do raid then

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2 hours ago, Windows7ge said:

I would advocate against doing this. You won't have access to the other 4TB and you're more likely to see hurt performance than anything.

 

If you really want to use them as one logical volume you can look into what's called a Spanned Disk. This doesn't do anything for performance and it does nothing for fault tolerance (but neither does RAID0) but it would allow you access to the full 12TB. Filling it up will likely degrade performance as well so be wary of that.

Thank you, by this do u mean it would make it "One" drive of 12tb just without splitting files across both drives? Because truthfully that might be my best bet as it will mostly be another spot for backups and large files/movies as its more less old still working drives not worth selling or trashing

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9 minutes ago, UnlinkedMink said:

Thank you, by this do u mean it would make it "One" drive of 12tb just without splitting files across both drives? Because truthfully that might be my best bet as it will mostly be another spot for backups and large files/movies as its more less old still working drives not worth selling or trashing

How the data is written to the disks exactly is still a bit of an enigma to me. Traditionally I was taught it filled one disk to 100% then moved onto the next. Not ideal for read/write performance. There are a few different implementations of it and how it works may vary depending on the platform/software but in essence yes. You would add the two disks to a pool and choose to create a Spanned Disk or Volume. It should show you 12TB (or 11.1TiB-ish) usable space.

 

Assuming you're using Windows checkout Windows Storage Spaces. See if it have an option for it. It may not be labeled as Spanned Disk there though it will behave the same/similarly.

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If you're just using 2 disks for storage with little concern about speeds Windows 7 and above has baked in features to handle this in Disk Management as @Windows7ge says (no Storage Spaces needed, unless you want to do more). Just have to convert the disks to dynamic and create a spanned volume. Benefit of spanned over striped in this case is that it writes sequentially instead of prioritizing location by read\write speed (so in a drive failure anything on the good one is usually recoverable, instead of just losing everything).

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On 12/1/2021 at 7:16 PM, UnlinkedMink said:

Hello,

I have a 4tb HD from when I first got my computer and recently ripped apart the enclosure of my 8tb external HD as I purchased a NAS (got specific NAS drives for it).

So my question is on my main rig if I were to place the 8tb and 4tb and were to put them into Raid 0 for the gained speed, I understand it would be a 4tb, but am I able to access that extra 4tb on the 8tb drive as a new partition? or does it completely make it unusable/non visible?

 

Thank you,

Mink

With RAID 0, this would give you 8 TB usable in the RAID array (RAID 1 would give you 4 TB).  Yes, good controllers, including software ones like Windows Storage Spaces, or even the last millennium dynamic disks, or some Intel onboard, will allow you to pass through the 4 TB as a second volume.  Anybody telling you otherwise has never looked very hard for a solution - though to be fair, it's a bit of an edge case

 

Though, as others have said, it's a poor idea in your situation.  RAID 0 increases read and write IOPS by about twofold, but you end up with a significantly less reliable storage volume ... and still very poor IOPS compared to literally any SSD, even DRAM-less.  I'd either concatenate them into one large volume, or just keep them as independent for more storage flexibility and predictable performance.

 

The actual use case for having multiple RAID volumes from a single pool of disks is so that you can carve volumes with specific redundancy and storage profiles for different purposes (and often different VMs).  So, for instance, you can have RAID 10 for your SQL, then some RAID 5 to store your backups, and RAID 6 to handle day to day volumes, all on a single pile of SSD and/or HDD in a storage server.  Or, another common one: RAID 10 for the OS, then RAID 5 for bulk storage, on 4 SSDs in the same server.

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4 hours ago, uncreativespace said:

Windows 7 and above

It's actually in every NT family OS, from 3.51 onwards, including XP and Vista.  It's hidden on some of the Home SKUs, but you can still create them from the command line.

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