Solved Storage Spaces showing low capacity and uneven disk usage.

Hi

I've just been migrating data to my new Storage Space on Windows 8. I had to do this in stages because I had a limited number of disks available to me. I had 2x 2TB disks in a nas box, and wanted to move them to a new server, and also added 2 more 2TB disks. Due to the nas being quite full, I started with a 4-disk pool consisting of 2x 2TB and 2x 500GB disks, and made a parity space.

My process was as follows:

1. Create parity space with the 2x 2TB and 2x 500GB disks
   
2. Copy all data from one of the disks in the nas to the space.
   
3. Remove 1x 500GB disk
   
4. Allow the space to repair
   
5. Add 1x 2TB disk from the nas into the pool
   
6. Copy the contents of the other nas disk to the space
   
7. Remove the 500GB and add the 2TB
   
8. Allow space to repair

The space is thinly provisioned at 4.85 TB which is what the GUI defaults to when I create a new parity space using all 4 disks. (I don't actually create the additional storage space). This is also what I calculated it to be (1.81*4*2/3).

Now the end result is very uneven disk usage and a low capacity warning, despite having what I think is about 57% total utilisation!
Here is a link to a screenshot of the space's setup:

https://dl.dropboxusercontent.com/u/60412649/20131010212940939.png

1) Can someone please help me figure out why it thinks there is low capacity?
2) How can I rebalance/redistribute the data evenly over the 4 disks?

Many thanks in advance!

Have a read through this thread that I posted a while back. It explains some of the reasons behind the extremely inefficient use of disk space as the result of using storage spaces.

http://www.eightforums.com/general-support/16615-confused-storage-spaces-parity-free-space.html

I don't use them, nor do I recommend them.

Thanks for the link. That is very interesting, and worrying.

However, none of my disks are close to full, and yet its telling me to add 1 disk! This is very confusing.
The average of my disks' usage percentages is 57%. Indeed, explorer reports 2TB free space from my 4.85TB total (inc parity).

Storage Spaces disconnects the volume size from the physical media size. You can specify a 100TB drive size if you want, you will just have to keep adding disks as you fill up physical storage.

Explorer will report a different size than what's left on physical disk.

I just built a new computer and set it up from the start to use an SSD for C:, and two 1TB HDD as a storage pool. While they are not very taxed for capacity yet, they seem to be distributing the data equally. Perhaps that is because I am using the Simple resiliency (RAID0 striping) configuration. I use an external network drive for backup and my internal HDD's are configured for maximum speed and capacity.

Perhaps the issue is due to using unequal drive sizes and parity for resiliency?

My Storage Space status:

I'd made some headway with this issue, and also found a way to balance (sort of!).

I think the issue I was having was because of the parity space's initial configuration with some 500GB disks. Windows seems to not do a very good job of working out the storage allocations on each disk.

What I did was create another parity space on the 4x 2TB disks, and then move the data from the old parity space D to the new parity space E.

Warning: This operation took an additional 50% disk space, even though it was a MOVE operation

Once the copying was complete (which took 36 hours, by the way!) I deleted the old storage space D, which free'd up the additional 50% (2TB).

Here is how my utilisation looks now (Dropbox link)

https://dl.dropboxusercontent.com/u/60412649/20131013121151196.png

As you can see, it has done some rebalancing too. Still not totally even, but a lot better than before.

I hope this information helps other people who were also taken in my the hype, as I was!