Best way changing FS on some disks, replacing two other disks AND adding secondary parity drive

[LXZ1982]

Hey there,

 

first post here ever. Been using Unraid for some time now but only now, that I am spending more time looking into it, that I get a better understanding of things.

I plan to do a minor upgrade to the server by adding a couple of drives. While doing this, I want to further optimize things.

The situation now:
1 parity drive
8 disks in the array - 6 of them in XFS, 2 in BTRFS
2 disks as a cache pool in BTRFS

To explain / defend myself why I used BTRFS for array disks: I didn't know it any better when I started out. I read that BTRFS was a newer filesystem than XFS and in my mind, I associated new as being better. I now know that XFS is preferend for array disks, hence I want to change this.

The next thing I want to do is replace two drives which are good but not purpose build. They are WD Green drives which I want to replace with WD Red Plus drives, like all other drives in the array.

Finally, I want to add a second parity disk.

Also, I want to add some more WD Red Plus disks to the array.

However, I am unsure about the optimal route to do all of this.

What I started with was that I added two new drives to the array. As a test, I moved the content from one of the BTRFS array disks to one of the new disks, stopped the array, changed the filesystem to XFS, started the array, formated and voila - one of the BTRFS disks is now XFS. Since this was a success, I am now moving the content from the remaining BTRFS array disk to the other new disk and will then change the filesystem aswell.

But then what?

Should I move the data from the WD Green to the other disks, then plug the WD greens, add the second parity drive and let parity rebuild? Or do you recommend a different approach?

Thanks for your suggestions.

[JonathanM]

59 minutes ago, LXZ1982 said:

I moved the content from one of the BTRFS array disks to one of the new disks, stopped the array, changed the filesystem to XFS, started the array, formated and voila - one of the BTRFS disks is now XFS. Since this was a success, I am now moving the content from the remaining BTRFS array disk to the other new disk and will then change the filesystem aswell.

Sounds like you have the file system changes well in hand.

 

As for rearranging the disks, perhaps the easiest way to present it is with a before and after list.

 

Current:

Parity1 - SN

Data1 - SN

 

Desired end state:

Parity1 - SN

Parity2 - SN

Data1 - SN

 

etc.

 

When you map out what drives you want to add vs. remove vs. move to new slots, we can give you 2 paths, safest and quickest.

 

Do you have full backups of anything important? Mass reconfigurations like this are a really easy way to accidentally lose data.

 

Also, when was your last parity check with zero errors, and are all the drives SMART tested good?

[LXZ1982]

2 hours ago, JonathanM said:

Sounds like you have the file system changes well in hand.

 

As for rearranging the disks, perhaps the easiest way to present it is with a before and after list.

 

Current:

Parity1 - SN

Data1 - SN

 

Desired end state:

Parity1 - SN

Parity2 - SN

Data1 - SN

 

etc.

 

When you map out what drives you want to add vs. remove vs. move to new slots, we can give you 2 paths, safest and quickest.

 

Do you have full backups of anything important? Mass reconfigurations like this are a really easy way to accidentally lose data.

 

Also, when was your last parity check with zero errors, and are all the drives SMART tested good?

 

 

Thank you very much for your assistance!

Current:

Parity1

Data1

Data2 - WD Green -> want to replace

Data3 - WD Green -> want to replace

Data4

Data5

.

.

.

Data10

Desired end state:

Paritiy1

Paritiy2

Data1

Data2 - WD Red Plus

Data3 - WD Red Plus

Data4

Data5

.

.

.

Data10
Data11

Data12

I have enough space free to move the content of Data2 and Data3 to other disks completely. All important data is backed up. Last parity check this past Friday. 0 errors. All Smart readings are good.

Edited May 7, 2022 by LXZ1982

[trurl]

You could add parity2, let it build, then replace/rebuild both data disks at the same time since you would have dual parity at that point.

 

Assuming the disks to be replaced are already in the desired filesystem no need to move any of their data, just rebuild it onto the replacements.