1.Reduce RAID by removing DISK (Zuletzt geändert von rsch an 28.02.2020 13:29:44)
For this I am going to assume there are 12 disks in the array, and each are 1TB big.
That means there is 10TB of storage. This is for example, provided you are not using more than 6 disks (6TB) worth of storage, then it doesn't matter what size they are.
Oblig disclaimer: None of this may be supported by Synology, so I would check with them if this approach can cause problems, backup beforehand, and shutdown any synology services beforehand. Synology use standard md raid arrays as far as I know, and they are accessible if the disk are moved to a standard server that supports md - so there should be no problems.
The sequence goes like this:
Find the main partition, using
Use this command to resize to the maximum it needs and no more:
To reduce the volume size, use lvreduce (make it a bit bigger just in case):
Now that the logical volume has been reduced, use pvresize to reduce the physical volume size:
If the resize fails, see this other question for moving the portions of data that were allocated at the end of the physical volume towards the beginning.
Now we have a 5.3T volume on a 10T array, so we can safely reduce the array size by 2T.
Find out the md device:
The first step is to tell mdadm to reduce the array size (with grow):
This is saying that in order to fit the current array onto 10 disks, we need to reduce the array size.
Now it is smaller, we can reduce the number of disks:
This will take a loong time, and can be monitored here:
But we don't need to wait.
Resize the PV, LV and filesystem to maximum:
Set spare disks as spares
Nothing to do here, any spare disks in an array are automatically spares. Once your reshaping is complete, check the status: