Different sized hard drives in raid

[SuperCookie78]

I have a bunch of hard drives just sitting around and i would like to use them in a NAS. I have 4 500GB drives and 2 1TB drives. 3 of the 500GB are WD Blues while the other is a WD green. the 1TB drives are dell rebranded WD enterprise drives. I would like to use RAID to combine these drives into a sizable NAS for my college dorm. I was thinking something along the lines of put the 500GB in RAID 0 and the 1TB in RAID 0 then having RAID 1 those raids together. I know its not the smartest thing in the world but is it possible?

[Lurick]

You'll only get the size of the smallest drive. So if you RAID 0 3x500GB drives and RAID 0 2x1TB drives then you'll get ~1.5TB of space from the subsequent RAID 1

[Pixel5]

it would certainly be possible but it would be really dumb.

[SuperCookie78]

Just now, Pixel5 said:

it would certainly be possible but it would be really dumb.

I mean what else am i going to use them for.

[Hairless Monkey Boy]

A better solution might be to create a single volume that extends across all the drives in Windows.

 

https://www.windowscentral.com/how-create-one-large-volume-using-multiple-hard-drives-windows-10

[SuperCookie78]

2 minutes ago, Lurick said:

You'll only get the size of the smallest drive. So if you RAID 0 3x500GB drives and RAID 0 2x1TB drives then you'll get ~1.5TB of space from the subsequent RAID 1

its 4 500GB. do you really think the overhead would bring me down to 1.5TB? i thought it would be around 1.8TB at the worst

[Lurick]

Just now, SuperCookie78 said:

its 4 500GB. do you really think the overhead would bring me down to 1.5TB? i thought it would be around 1.8TB at the worst

Oh, for some reason I thought you said 3 500GB drives. I mean in that case yah, 2TB or ~1.8TB usable.

[SuperCookie78]

2 minutes ago, HairlessMonkeyBoy said:

A better solution might be to create a single volume that extends across all the drives in Windows.

 

https://www.windowscentral.com/how-create-one-large-volume-using-multiple-hard-drives-windows-10

i would likely wouldn't be using windows as my OS for the NAS.

[Zenith_X1]

Assuming that RAID 0 works at all for non-identical performing drives (if that WD Green is not 7200rpm like the WD Blues you're going to run into issues) then that could work nicely.  However if you are trying to make a RAID 0+1 setup using the 2 1TB HDDs, you may find that RAID treats the 1 TB drives as 500GB drives which would be terribly inefficient.

 

You might have more success if you ran the two 1 TB HDDs in RAID 1 as a parity backup for important things, and 3 of the WD Blues in RAID 0 for fast storage of less important media (such as Steam downloads in the case of my 3x 750 GB RAID 0 setup).  The WD Green could be for storage of old files, cloud storage hard offline backups, movies, whatever suits your fancy.

 

Edit: Forgot to add, I think that if you ran 4 RAID 0 drives in RAID 1 with 2 other RAID 0 drives, you would lose the speed benefit of having 4x drives in RAID 0 because the write-speed of the 2x drives in RAID 0 bottlenecks the write-speed of the other 4 synced drives.

[SuperCookie78]

5 minutes ago, Zenith_X1 said:

Assuming that RAID 0 works at all for non-identical performing drives (if that WD Green is not 7200rpm like the WD Blues you're going to run into issues) then that could work nicely.  However if you are trying to make a RAID 0+1 setup using the 2 1TB HDDs, you may find that RAID treats the 1 TB drives as 500GB drives which would be terribly inefficient.

 

You might have more success if you ran the two 1 TB HDDs in RAID 1 as a parity backup for important things, and 3 of the WD Blues in RAID 0 for fast storage of less important media (such as Steam downloads in the case of my 3x 750 GB RAID 0 setup).  The WD Green could be for storage of old files, cloud storage hard offline backups, movies, whatever suits your fancy.

I was thinking maybe just selling the green and buying a blue. raiding the 500GB together to get a 2TB pool. then raiding the 1TB together to get 2TB then RAID 1 on those pools. so it would be RAID 0+0+1. I could also RAID 0 the 2 500 to make 1TB twice, then RAID 10 the 4 1 TB drives.

[Zenith_X1]

6 minutes ago, SuperCookie78 said:

I was thinking maybe just selling the green and buying a blue. raiding the 500GB together to get a 2TB pool. then raiding the 1TB together to get 2TB then RAID 1 on those pools. so it would be RAID 0+0+1. I could also RAID 0 the 2 500 to make 1TB twice, then RAID 10 the 4 1 TB drives.

Edited my post too late, so I'll rephrase with what you replied.  I think that if you ran 4 RAID 0 drives in RAID 1 with 2 other RAID 0 drives, you would lose the speed benefit of having 4x drives in RAID 0 because the write-speed of the 2x drives in RAID 0 bottlenecks the write-speed of the other 4 synced drives.  If that speed bonus doesn't matter then cool.  I like your new idea of running 2x (1TB + 2x500GB) in RAID 1 a lot more because that better distributes the risk in the event of drive failures.

[SuperCookie78]

2 minutes ago, Zenith_X1 said:

Edited my post too late, so I'll rephrase with what you replied.  I think that if you ran 4 RAID 0 drives in RAID 1 with 2 other RAID 0 drives, you would lose the speed benefit of having 4x drives in RAID 0 because the write-speed of the 2x drives in RAID 0 bottlenecks the write-speed of the other 4 synced drives.  If that speed bonus doesn't matter then cool.  I like your new idea of running 2x (1TB + 2x500GB) in RAID 1 a lot more because that better distributes the risk in the event of drive failures.

i mean if i was after speed i could just RAID 0 the 500GB together then raid 0 the 1TB together. But instead of RAID 1 the pools together i just have it clone the 500GB array to the 1TB array every night while i'm asleep. but I think I like my new idea of 2x 2 500GB raid 0'ed giving me 4 1TB drive to work with. But with that now i have the option for RAID 5 which would give me an extra TB of usable space but means i could only use 1 1TB drive.

[Senzelian]

Synology actually has an option to enable using different sized drives, which is called SHR. (Synology Hybrid RAID)

https://www.synology.com/en-global/knowledgebase/DSM/tutorial/Storage/What_is_Synology_Hybrid_RAID_SHR

The thing is tho, you need a Synology NAS.

 

Unless...

https://xpenology.org
https://xpenology.com/forum/topic/6901-dsm-6-where-is-option-to-use-shr/

 

Never tried it, but maybe worth a shot?

 

Or if you're still building a box for the NAS anyways, you might think about buying a used Synology NAS.

 

 

[Zenith_X1]

9 minutes ago, SuperCookie78 said:

i mean if i was after speed i could just RAID 0 the 500GB together then raid 0 the 1TB together. But instead of RAID 1 the pools together i just have it clone the 500GB array to the 1TB array every night while i'm asleep. but I think I like my new idea of 2x 2 500GB raid 0'ed giving me 4 1TB drive to work with. But with that now i have the option for RAID 5 which would give me an extra TB of usable space but means i could only use 1 1TB drive.

I didn't know what your use case was for the NAS

[SuperCookie78]

3 minutes ago, Senzelian said:

Synology actually has an option to enable using different sized drives, which is called SHR. (Synology Hybrid RAID)

https://www.synology.com/en-global/knowledgebase/DSM/tutorial/Storage/What_is_Synology_Hybrid_RAID_SHR

The thing is tho, you need a Synology NAS.

 

Unless...

https://xpenology.org
https://xpenology.com/forum/topic/6901-dsm-6-where-is-option-to-use-shr/

 

Never tried it, but maybe worth a shot?

 

Or if you're still building a box for the NAS anyways, you might think about buying a used Synology NAS.

 

 

I always used their RAD calculator and had no idea what SHR was. I have not built the box yet so a synology box might be an option. SHR would basically be RAID 5 of my new plan of 2 arrays of 2 500GB raid 0 and 2 1TB. SHR-2 leaves 1TB unused. 

[SuperCookie78]

4 minutes ago, Zenith_X1 said:

I didn't know what your use case was for the NAS

at the moment just off loading twitch vods, youtube videos, and raw recordings. i might let some of my roommates use it but i don't think they need it. 

[Zenith_X1]

4 minutes ago, SuperCookie78 said:

at the moment just off loading twitch vods, youtube videos, and raw recordings. i might let some of my roommates use it but i don't think they need it. 

That's really cool.  RAID 5 is a nice choice for maximizing that space with redundancy as long as the NAS has a RAID controller that can create a RAID 5 array.  I believe some older, cheaper designs were only capable of RAID 0, 1, and 10, but that may have changed by now.  RAID 5 is more complicated as you probably already know

 

Edit:  Did some quick research, yep RAID 5 is perfect for this

[n0stalghia]

unRAID allows you to have drives of different sizes in the system. However, one of the drives is reserved for parity, and it needs to be equal or bigger than the biggest drive in the system.

 

unRAID goes through your data bit-wise and calcualtes uneven parity, so it would look something like this for two drives of different size:

 

Parity = Drive 1 = x TB, Drive 0 = y TB, x > y

 

           | Drive 0        | Drive 1         | Parity

Data   | 1                  | 0                  | 0              # 1+0+0=1, uneven parity

Data   | 1                  | 1                  | 1              # 1+1+1=1, uneven parity
Data   | 0                  | 0                  | 1              # 0+0+1=1, uneven parity
Data   | missing = 0  | 1                  | 0              # 0+1+0=1, uneven parity
 

Drive 1 is larger than Drive 0, but it needs to be <= Parity drive so parity can be calculated. However, if any data is missing for the comparison (because drive 0 is smaller), the system just assumes a 0 and can still calculate the parity.

 

This also allows on-the-fly expansion of your storage. You can add a new drive at any time.

 

PS. It is recommended to use a high-speed drive (I use a SATA III SSD) as a cache drive, since writing to mass storage in unRAID is slow.

 

[Nick7]

Depending what you intend to use it, if you want redundancy with MAX capacity:

On 1TB drives create 2 partitions of 500GB.

Create one RAID5 with 4 500GB drives and 2 500GB partitions on 1TB drive. That's 2.5TB.

You now have 2x500GB leftover, so use RAID1 on that, which is 500GB.

 

Now, depending what you want - you can use one 2.5TB and 500GB RAID for whatever you need.

You can:

1) Use them separately, 2.5TB and 500GB

2) You can create spanned drive, so concatenate those two as one 3TB drive

3) You can put them in LVM, and carve out what you want out of them.

 

One thing to keep in mind - if accessing 500GB RAID at same time as 2.5TB RAID, you will have performance penalty. For using it as a storage, that's fine though. If you ware worried about this, simply ignore second 500GB RAID, and do not use it.

[Salacious B Crum]

I would second unRAID try it for free for up to 60 days I think for your use case it would apply take your largest drive as parity the rest is the total of the remaining drives and as stated when you need more just chuck another drive of any size as long as its not larger than parity but that is not a problem either if you get your hands on a deal for a larger drive just make that the parity drive and pull down the original into the array and your golden