I want to join five drives (4x50GB, 1x100GB) into one pool/drive/file system using storage spaces. I do also want to use the "Mirror" option.
So, in my opinion, I should be able to get 150GB mirrored space. But I am not able to achieve this.
- Add all drives to the pool at once.
- Pool has 296GB capacity (295GB free) => fine
- Add new virtual drive (mirror, 2-way, fixed size, max size = 126GB) => that is less than the 150GB I expected
- Now the pool still has 296GB capacity and 40GB free. This is correct, but I would like to also use those 40GB. Even if I create a new virtual drive, I get the message that there are only 0,00 Bytes available.
- First add the 100Gb drive and two 50GB drives
- Pool has 198GB capacity (197GB free) => fine
- Add new virtual drive (mirror, 2-way, fixed size, max size = 91GB) => that is less than the 100GB I expected
- Now the pool still has 198GB capacity and 12,5GB free.
- Now I add the two remaining 50GB drives to the pool => pool has 296GB capacity (111GB free)
- I can increase the size of the virtual drive to 143GB, now there are 6,5GB free in the pool => this is already much better than the first try, but still not perfect.
I am not able to reach a better utilization. I would be glad for ways to use all of the pool space.
The tests above were done in a virtual machine environment to demonstrate the behaviour, in real life I plan to use bigger SSDs (1x1TB, 4x512GB), so it is not like I can just buy two cheap hard drives instead to do the job.
Thanks for your help!