I've read how to replace a cache drive, but for my situation I am wondering if this is possible.

 

I have two 120GB SSDs in a cache pool, and I am wanting to move to a single 275GB SSD due to device limits. I was wondering since they are pooled, if I replace one of the 120s with my 275, and then restart the array if unRaid will automatically populate the new 275. After I confirmed (don't know how) that the new 275 drive has been copied to, I would just take the 2nd 120 drive out of the array.

 

I plan on returning the two 120gb SSDs and getting an additional 5TB for my array. I am not worried about a cache pool because I will periodically backup the cache drive.

 

I have never worked command line so the MC method to copy to the new drive would be way more work than I can handle.

I was wondering since they are pooled, if I replace one of the 120s with my 275, and then restart the array if unRaid will automatically populate the new 275. After I confirmed (don't know how) that the new 275 drive has been copied to, I would just take the 2nd 120 drive out of the array.

 

It's possible, there are procedures for that in the FAQ for unRAID v6.

Someone pointed out to me that going from 2 cache drives in btrfs cannot be swapped to 1 cache drive and be rolled back off of btrfs without formatting the drive. Can anyone confirm this?

...and be rolled back off of btrfs without formatting the drive.

 

If by "rolling back" you mean change to another filesystem, then you can't do it without formatting the cache.

...and be rolled back off of btrfs without formatting the drive.

 

If by "rolling back" you mean change to another filesystem, then you can't do it without formatting the cache.

 

Yeah, that's what I mean. I figured if going from 2 drives to 1 I would switch to xfs since everyone says it's more stable, but since I'm not that savvy I might just have to leave it in btrfs and hope I don't run into any problems.

 

I'm currently looking for cloning software that will clone one btrfs drive to a xfs drive, which would save me a lot of headaches.

I'm not sure I understand what formats your cache drives are currently in, but I just did something like this the other day. I had 2 x Sandisk 120GB Plus SSD's in the cache. I pulled out one of them and added a Samsung 850 Evo 250GB and let it rebuild onto the new drive. Then I pulled out the other Sandisk 120GB drive and added another Samsung 850 Evo 250GB drive and let it build onto that one. Everything worked no problems and all my dockers and vm's are fine. Everything was in btrfs the whole time so I'm not sure if this applies to you.

I'm not sure I understand what formats your cache drives are currently in, but I just did something like this the other day. I had 2 x Sandisk 120GB Plus SSD's in the cache. I pulled out one of them and added a Samsung 850 Evo 250GB and let it rebuild onto the new drive. Then I pulled out the other Sandisk 120GB drive and added another Samsung 850 Evo 250GB drive and let it build onto that one. Everything worked no problems and all my dockers and vm's are fine. Everything was in btrfs the whole time so I'm not sure if this applies to you.

 

I'm trying to go from two btrfs drives to one xfs drive.

I am not worried about a cache pool because I will periodically backup the cache drive.

I'm trying to go from two btrfs drives to one xfs drive.

I'm not trying to be a smartass, but it will probably come off like that.

 

Back up your current BTRFS cache pool using the method that you were planning to use anyway, physically remove and replace the drives and restore your backup to the new XFS cache disk. If it doesn't work, then your backup strategy isn't going to work either. This is the best time to test out your strategy, because if it doesn't work, you still have the intact cache drives to work with.

I am not worried about a cache pool because I will periodically backup the cache drive.

I'm trying to go from two btrfs drives to one xfs drive.

I'm not trying to be a smartass, but it will probably come off like that.

 

Back up your current BTRFS cache pool using the method that you were planning to use anyway, physically remove and replace the drives and restore your backup to the new XFS cache disk. If it doesn't work, then your backup strategy isn't going to work either. This is the best time to test out your strategy, because if it doesn't work, you still have the intact cache drives to work with.

 

I think that's what I will try, I just hope that if I replace one drive it won't make me use btrfs since it will still be in a pool. If it doesn't work I'll have that intact drive that I took out as a backup.

I am not worried about a cache pool because I will periodically backup the cache drive.

I'm trying to go from two btrfs drives to one xfs drive.

I'm not trying to be a smartass, but it will probably come off like that.

 

Back up your current BTRFS cache pool using the method that you were planning to use anyway, physically remove and replace the drives and restore your backup to the new XFS cache disk. If it doesn't work, then your backup strategy isn't going to work either. This is the best time to test out your strategy, because if it doesn't work, you still have the intact cache drives to work with.

 

I think that's what I will try, I just hope that if I replace one drive it won't make me use btrfs since it will still be in a pool. If it doesn't work I'll have that intact drive that I took out as a backup.

You will have to remove both so you don't have a cache anymore, then add the new drive as cache and select XFS for its filesystem and let it format.