Replace 1TB drives with 8TB drive in NON cache pool

[Tymarand]

Hello all,

I think I have a unique situation and I'm not sure how to proceed.  I may have screwed the pooch on this one by the way I built my unRAID system...

 

unRAID Version 6.10.3 2022-06-14 (latest as of this post)

 

I have searched and searched and can't find my exact scenario so I'm hoping someone can assist.  I have only found information on replacing CACHE disks but not regular pool disks.

 

My current setup is as follows:

Dell PowerEdge R720

LSI 9207-8e flashed IT mode

NetApp DS4246 with 21 disks installed

 

unRAID disk configuration:

1. One 8TB parity disk under "Array Devices"
2. One 3.3TB disk under "Array Devices" (various drives hardware raid)
3. One 360GB cache disk under "Pool Devices" (3x120GB SSDs hardware raid)
4. 20 disk Raid 0 pool under "Pool Devices" (I needed capacity, not redundancy)
   • 9 x 1TB disks
   • 5 x 2TB disks
   • 6 x 8TB disks

 

I would like to remove 8TB worth of disks, either 8 x 1TB or 4 x 2TB and replace with a new 1 x 8TB disk.

 

Is this possible?  I have found through testing that I can remove a disk from the pool and mount it under "Unassigned Devices", I'm assuming because I have Raid 0?  Could I then just throw the 8TB disk in and copy the data over?

 

Any and all help would be appreciated.  If you think it's not possible, I'm willing to accept any suggestions for rebuilding my system to better accommodate disk replacement/upgrades*.

 

Edit: *Rebuild for capacity more so than disk failure protection which I assume is what the parity drive is for.

 

Regards,

Chris R.

Edited July 13, 2022 by Tymarand
Added info

[trurl]

21 minutes ago, Tymarand said:

Rebuild for capacity more so than disk failure protection which I assume is what the parity drive is for

 

Parity provides redundancy for array disks, not for pool disks.

[Tymarand]

Just now, trurl said:

 

Parity provides redundancy for array disks, not for pool disks.

Thank you!  Having said that, are you implying there's no way to replace/upgrade pool disks?  I know that cache drives have a replace/upgrade procedure, would it be the same?

[JorgeB]

1 hour ago, Tymarand said:

20 disk Raid 0 pool under "Pool Devices"

 

46 minutes ago, Tymarand said:

Having said that, are you implying there's no way to replace/upgrade pool disks?

It's possible but the GUI only supports replacing devices from redundant pools, you could do it manually though.

[Arbadacarba]

Do you mean to say that you have a raid card with a raid0 configured? Or are you just assuming that the pool is raid 0?

 

7 hours ago, Tymarand said:

Is this possible?  I have found through testing that I can remove a disk from the pool and mount it under "Unassigned Devices", I'm assuming because I have Raid 0?  Could I then just throw the 8TB disk in and copy the data over?

 

Raid 0 Specifically precludes this... In raid 0 pulling one of the disks completely breaks all of the disks... But I thought they all had to be the same size?

 

RAID 0[edit]

See also: JBOD

Diagram of a RAID 0 setup

RAID 0 (also known as a stripe set or striped volume) splits ("stripes") data evenly across two or more disks, without parity information, redundancy, or fault tolerance. Since RAID 0 provides no fault tolerance or redundancy, the failure of one drive will cause the entire array to fail; as a result of having data striped across all disks, the failure will result in total data loss. This configuration is typically implemented having speed as the intended goal.[2][3] RAID 0 is normally used to increase performance, although it can also be used as a way to create a large logical volume out of two or more physical disks.[4]

A RAID 0 setup can be created with disks of differing sizes, but the storage space added to the array by each disk is limited to the size of the smallest disk. For example, if a 120 GB disk is striped together with a 320 GB disk, the size of the array will be 120 GB × 2 = 240 GB. However, some RAID implementations allow the remaining 200 GB to be used for other purposes.

The diagram in this section shows how the data is distributed into stripes on two disks, with A1:A2 as the first stripe, A3:A4 as the second one, etc. Once the stripe size is defined during the creation of a RAID 0 array, it needs to be maintained at all times. Since the stripes are accessed in parallel, an n-drive RAID 0 array appears as a single large disk with a data rate n times higher than the single-disk rate. (wikipedia)

 

So that would mean that your raid 0 array would be 20TB

[Arbadacarba]

Oh, and I menat to point you towards unBALANCE if in fact you are not running a Raid 0 Array underneath unraid

[Tymarand]

I'm just as confused as you.... not only that, ALL of my disk space isn't being used/seen...

 

Here is what I see in the pool settings:

 

 

Disk usage:

 

 

I have 67TB worth of disk space but only 51TB is being utilized.  That leads me to believe that SOMETHING is in Raid 1, which is hinted at within the pool settings.

 

Thank you again for everyone's assistance.  In a nutshell, I have hundreds of Chia plots that I'm hesitant to shuffle around.

 

Regards,

Chris R.

 

*I have unBALANCE installed as well but doesn't show the pool disks when I go to the UI.

Edited July 14, 2022 by Tymarand
Added info

[Tymarand]

15 hours ago, Arbadacarba said:

Do you mean to say that you have a raid card with a raid0 configured? Or are you just assuming that the pool is raid 0?

Yes to the first question, no to the second - Sorry for the confusion.

 

I have a hardware RAID card in my R720 that I have used to create RAID 0 disks from the internal 2.5" disks... one is 3 x 120GB SSDs = 1 x 360GB and the rest of the drives are mashed together for another RAID 0 = 3.3TB

 

All my other disks are housed in a NetApp DS4246... the parity disk and all of the pool disks

 

In my screenshots above, you can see the labels for the PERC are the hardware RAID disks.

Edited July 14, 2022 by Tymarand

[JorgeB]

15 minutes ago, Tymarand said:

That leads me to believe that SOMETHING is in Raid 1, which is hinted at within the pool settings.

Data is in raid0, probably a btrfs issue, does not always calculate correct spaces for pools with different size devices, but all the space should be usable.

 

16 minutes ago, Tymarand said:

In a nutshell, I have hundreds of Chia plots that I'm hesitant to shuffle around.

Since Unraid supports a lot of pools I would recommend using smaller pools, i.e., I also do some "farming" and have for example 6x1TB, 5x2TB, 3x3TB, 2x8TB, etc, they all have a share called plots, so no need to add each pool separately to Chia and it's much easier to manage, also if there's a disk problem you only lose one pool.