Storage Spaces Calculator?

[timdine]

Is there any Storage Spaces calculators out there geared towards "home" use?  

 

I've found a couple which seem to be more data center based.  I'm looking to try a few different configurations with a few different drive configurations and redundancy (mirror vs parity) options to see what I'd come out with without having to actually configure the drives.

[Guest]

Make a interactive excel table or access database.

[timdine]

That's what I'm looking for.  Something like Synology RAID Calculator would be great.  What I'm missing right now is the rules and what combinations are possible to be able to build something I could be confident in.  

 

I've gathered pieces of rules but not enough to confidently answer my question, best configuration using a set of drives I have (2x4tb, 2x8tb), will it waste space going mirror/parity (probably not parity) and can I make it much better with a small change.

[GDRRiley]

wen using only 2 drives raid 1 is your only option. when over 3 you can use raid 5 for 1 drive fail over and when over 4 you can use raid 6 for 2 drive fail over. Raid 5 is recommended by me  for sub 6 drive arrays and after that go for raid 6. there are also hybrid ones like raid 60 or 50. striping together raid 5s or 6s (wouldn't do it with raid 5).

[brwainer]

if you are specifically talking about "Storage Spaces" by Microsoft, and not using storage space as a generic term, then calculating can be a little difficult since the "RAID" type calculations are done at the virtual disk level, not when the disks are added to the array itself. What this means it that if you put in 2 drives, you can have one virtual disk be Simple storage (like RAID0) and another virtual disk be Mirror (like RAID1). With 4 or more disks, then a Mirror disk automatically starts acting like RAID10, doing striping as well as 2 file copies. With 5 or more disks you can use Parity virtual disks, which are like RAID5, and you can make Mirror disks that keep 3 copies of each block instead of 2. With 7 or more disks you can use Parity with 2-drive-fault-tolerance, which is like RAID6. The only other system I know of that works this way is CEPH.

So what does this mean for calculation? As far as I'm aware, there isn't any calculators out there that tell you how much space a given set of disks will give you if you want to have some space be one type of virtual disk and some space be another type. What I suggest you do is work with normal RAID calculators to get a feel for how much space you'd get in each virtual disk, say if you devoted half your physical disk space to Mirror and half to Parity. You can also play with Ceph calculators like this one - just pretend that "Nodes" are individual disks, and that its only calculating a Mirror virtual disk. The replication and repair between Storage Spaces Mirror and Ceph is basically the same.