RAD of the RAID

LunarMist

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Can I RAID a RAID or is that too much, for example 2TB, 2Tb, and 4TB?
 

Chewy509

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You can**.
Remember RAID10, RAID50 and RAID60 are technically RAID on RAID schemes...
eg RAID10 is RAID 1 of multiple RAID 0 arrays or a RAID 0 of multiple RAID 1 arrays. (depending on your controller/software)
likewise, RAID50 is a RAID 5 of multiple RAID 0 arrays.

Using your example, with 2x TB and a 1x 4TB drive, you could technically create a RAID 0 of the 2x 2TB drives creating a 4TB RAID 0 array, then use that as a member with the other 4TB drive in a RAID1 array.

Or you could create a RAID 5 using the 3 drives, with a spare 2TB on the third drive for something else.

** Disclaimer, it depends entirely on your controller and software setup you are using.
 

LunarMist

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I should have explained that I wanted to have 8TB, but not use the dreaded JBLOD. I have several extra drives and cannot figure out how to use them. I have three 2TB M.2 SSDs, a spare 4TB SATA III SSD and several 2TB SATA III SSDs. There seems to be no way to use the M.2 drives through USB and I will never have enough PCIe lanes to spare on them. This is where the PC totally sucks compared to the MAC Thunderbowls.
 
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Chewy509

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For your M.2's, would something like this be possible? (not recommending this one in particular, just an example of what is out there).


IIRC, I'm not aware of any M.2 NVMe to USB controllers. There are a few Thunderbolt enclosures that have 2-3x PCIe x16 slots (mainly for GPUs), but have seen them loaded with M.2 NVMe's via adapter cards like the one above. Then you just need a Thunderbolt adapter for your PC.


And with a Thunderbolt controller, then you could use one of the many SATAIII external enclosures for your SSDs.
Or just get a SATA III PCIe controller card for your PC if you don't have enough SATA ports available.

ZFS will most likely be the only solution that lets you group a bunch of different sized drives together and span writes/reads across the drives, but it'll still be considered a JBOD type array, as their is no redundancy in it.
 

LunarMist

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Thanks. I'm not sure all that is worth it.
Maybe I can hardware RAID 0 two 2TB SSDs with the SATA controller (same models) and then Windows RAID 0 those with the 4TB SSD (also same model)? Then I will figure out the M.2 drives later.
 

Mercutio

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I use PCIe cards to add support for extra addressable nvme drives. I just dedicate them to different I/O tasks with the idea of spreading out disk writes to improve drive longevity. I do have a 4TB RAID0 of nvme drives but that's honestly just to get a single large volume rather than any specific need for faster I/O.
 

LunarMist

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I did the same with the 2x2TB EVO Plus RAID 0 for the past three years before upgrado to the 2x4TB SN850X last week. The SN850X are great but
I'd like to keep using the EVO Plus somehow, since they were the older faster ones, not the ones they started selling in 2020. They are still at over 98% usage. I also have an SN750, used for a week but I'll probably put that somewhere else.

Unfortunately the stupid limitation of most systems (inlcuding the X670E) that never have enough lanes precludes me from adding any cards without losing something else. The motherboards with more onboard stuff can't use all the PCIe slots or M.2 slots or SATA ports or something all at the same time.

Of course anything I'm doing now is only temporary and realistically a February 2023 new build on X670E will probably have a short lifetime as a main system.
 

ddrueding

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Amazon has a number of external USB 3.2 enclosures for M.2 NVMe drives. You will not get full performance from them, but if they are just laying about it is a reasonable use of them to just be super thumbdrives.
 

LunarMist

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I have a few and none are very reliable or speedy. My old 2TB M.2 860 EVO SATA is as fast or faster, but I don't need a whole pile of 2TB. It's just too small these days. I really want RAID and that is PCIe (Thunderbowls) only.
 

LunarMist

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Is there some way to get more than one M.2 SSD from 4 pcie lanes if speed is not importante?
 

LunarMist

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It is listed as x16 and that it is for a few Asus cards or others with bifurnication. Are you sure that can use only x4 lanes?
 

Mercutio

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If you REALLY don't care, they made little 1x to 4x Physical adapters that just put your slot on the end of a ribbon cable.
You can also get USB 3 to 4 1xPCIe slots, which sounds weird but found a lot of use among the mining community. Remember that PCIe will operate fine with fewer lanes so long as the card fits in the available slot. You'd be talking about making a mess of adapters, though.

Or you could stick one of the Jmicron nvme to 5x SATA I linked to in another thread and just do everything that way.
 

ddrueding

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It is listed as x16 and that it is for a few Asus cards or others with bifurnication. Are you sure that can use only x4 lanes?
Nope, my mistake for not reading your question well enough. That card does need 16x and gives 4x 4x. Please disregard. It will work in non-ASUS boards though; I ran one in a supermicro for a while.
 

LunarMist

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Which is better for the SATA III SSDs, n=3 in RAID 0 or n=4 in RAID 5? I read that there is some kind of RAID 5 in Windows, but I'm not seeing the Dymanic Disk. I would be using random 4TB WD or Sandisk or Samsung SSDs, not all the same model if that matters.
 
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