Hello lads !

I'm currently adding two 4TB disks (CMR, 7400) and removing four 2TB disks (SMR, 5400)

And I am unsure of the way to actually do this.

I removed the old 2TB parity disk and replaced it with a 4TB one, the parity check is done.



My reason for this is, as you can see, those 4 disks stand behind a ServeRAID card I can't flash to HBA, I got a disk array, HBA card and I'm now installing 3.5 LFF drives instead of 2.5 SFF drives as well, cheaper, bigger, better, with smart access.

However, I have 5TB on those disks and I am unsure of the way to do this, here's what I got from reading the forum left and right and would like one last "yeah go ahead".

- Add the two new disks to the array
- Copy all the files from disk 1/2/3/4 into the two new disks using unbalanced
- New config, remove the 4 old disks
- ???
- Profit

Did I get the steps right ? I have a lot of things on the server, Would like to keep the parity running while doing all that if possible.

Thank you ! :)

Better way is to replace one disk at a time. Remove current disk and replace with new, bigger disk. Let Unraid rebuild the data onto the new disk.

Doing it this way, if any issue arises, all of your data is backed up on the disk you removed.

https://docs.unraid.net/unraid-os/manual/storage-management/#replacing-a-disk-to-increase-capacity

I'm currently adding less disks than I'm removing, I could do that for two disks, what about the two last ones ?

Edited July 1, 20251 yr by Niyah

once two of the old 2TB disks are upgraded to 4TB through the normal disk replacement/upgrade procedure for each disk one at a time, you should have more than enough free space to run the Unbalance plugin to scatter the data from the remaining 2TB disks to the new ones, then you can run a disk removal procedure.

Those steps are just as you have mentioned in the original post, but it is easier and safer to upgrade the existing disks first, less risks that way as we keep the parity valid and protecting you through the whole process. You can also upgrade a single disk, then unbalance to clear one old disk, then remove that old disk, then upgrade the second disk and repeat if you wanted to do reuse the old disks slightly faster in something else.

There are two ways to remove disks from the array once they are empty and the data is confirmed safely on the new disks, the easy way is to go to tools>new config then just don't map the old disks when you re-assign the disks, but that will require a parity rebuild. the other method zeroes out the disks to ensure the parity stays valid. both are details in the link above.

I started replacing a first disk yesterday, I'll replace the second one when the data rebuilding is done and then use unbalance.

Thanks you ! :)