Going from 3 cache drives to 1

[s1l3nce]

My current cache pool looks like this:

 

I would like to convert that pool into a single drive and simply use the 250 GB Samsung SSD. Which steps do I need to follow?

PS: It is mostly for the sake of learning; I know that having a redundant cache is ideal. My current Unraid setup is just a testing/learning environment. I want to familiarise myself with everything that I need to know before I move all my data to Unraid. The plan will be to use 2 NVME drives mirrored.

Edited February 21 by s1l3nce

[itimpi]

You need to make sure that the pool is completely balanced to RAID1 initially.   You can then remove 1 drive and then you need to rebalance it to RAID1 gain with just 2 drives present.   You can then remove the second drive.  You now want to change it to use the Single profile.

[s1l3nce]

27 minutes ago, itimpi said:

You need to make sure that the pool is completely balanced to RAID1 initially

Done.

27 minutes ago, itimpi said:

You can then remove 1 drive

You mean stop the array and remove it from the pool? Like this?

[JorgeB]

Yes, if the array does not start post the diags, pool may still be reporting single profile.

[s1l3nce]

The array started but the cache drives are showing activity and the console is showing this

 

 

 

Edited February 21 by s1l3nce

[s1l3nce]

And I just got this message on the console

Should I proceed with the next disk?


Btw, on the first disk removal, I clicked here where it says "balanced" and a percentage showed up. But once the first disk was removed, when I clicked on it again, it did not show any activity, although there was activity between the drives, like I showed in the console.

 

Edited February 21 by s1l3nce

[JorgeB]

That's all normal, it's balancing, you can remove the other one now.

[s1l3nce]

Hum... this looks weird. I removed the last disk, started the array and then this happened:



A parity check started and it says that there is a missing (not installed) disk on the first slot.

Edited February 21 by s1l3nce

[s1l3nce]

This is what I see on the slot of the last SSD I removed (that now shows as Not Installed)

 

2 hours ago, itimpi said:

You now want to change it to use the Single profile.

It does not seem to be possible to activate single profile from this menu now.

[JorgeB]

Parity check would be unrelated, maybe an unclean shutdown, for the pool you can reimport with the device in the top slot, stop array, unassign the pool device, start array, stop array, re-assign the pool device, start array.

[s1l3nce]

4 hours ago, JorgeB said:

Parity check would be unrelated, maybe an unclean shutdown.

It's weird because I stopped it every time during this process. It happened after starting the array with only one SSD.

 

Will try your suggestion and report back.

[s1l3nce]

4 hours ago, JorgeB said:

for the pool you can reimport with the device in the top slot, stop array, unassign the pool device, start array, stop array, re-assign the pool device, start array.

It worked, brother. And, curiously enough, the parity check corrected itself after that without having to do a full parity check. 

Thanks a lot for all the help 🙏

[s1l3nce]

I just had a problem. I rebooted the system and when Unraid loaded back, my array was stopped. I tried to manually restart it and it gave me this error:

 

I've just followed this advise to resolve the issue: