How does Windows Storage Spaces Columns work?

%3CLINGO-SUB%20id%3D%22lingo-sub-1053461%22%20slang%3D%22en-US%22%3EHow%20does%20Windows%20Storage%20Spaces%20Columns%20work%3F%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-1053461%22%20slang%3D%22en-US%22%3E%3CP%3EI%20can't%20find%20explanation%20on%20how%20Windows%20uses%20columns%20in%20Storage%20Spaces.%20I%20have%20originally%20thought%20it%20works%20like%20this%3A%3C%2FP%3E%3CUL%3E%3CLI%3EI%20create%20pool%20with%20parity%20virtual-disk%20with%203%20columns%2C%203%20drives%2C%20giving%20it%20capacity%20of%202%20drives%20or%2066%20percent%20efficiency.%3C%2FLI%3E%3CLI%3EI%20add%203%20more%20drives%20of%20the%20same%20capacity%20into%20the%20pool%20and%20extend%20the%20virtual-disk%2C%20which%20will%20again%20allow%20me%20to%20use%20additional%20capacity%20of%20the%202%20drives%20I%20added.%3C%2FLI%3E%3C%2FUL%3E%3CP%3ENow%20I'm%20getting%20lost.%20When%20I%20start%20writing%20data%20to%20this%20expanded%20virtual-disk%2C%20does%20it%20split%20every%20write%20into%202%20rows%2C%20and%20every%20row%20into%202%20columns%20and%20then%20calculates%20parity%20for%20each%20row%3F%20That's%20what%20I%20originally%20thought%2C%20but%20then%20Windows%20%3CA%20href%3D%22https%3A%2F%2Fsuperuser.com%2Fquestions%2F1506372%2Fhow-can-storage-spaces-run-parity-space-where-numberofdisks-is-not-a-multiple-of%2F1506394%3Fnoredirect%3D1%23comment2279689_1506394%22%20target%3D%22_self%22%20rel%3D%22nofollow%20noopener%20noreferrer%20noopener%20noreferrer%22%3Easked%20me%3C%2FA%3E%20to%20add%202%20drives%20into%203-column%20parity%20Storage%20Space%2C%20for%20a%20total%20of%207%20drives%2C%20which%20makes%20no%20sense%20to%20me.%20What%20am%20I%20missing%3F%20How%20does%20Storage%20Spaces%20write%20data%3F%3C%2FP%3E%3C%2FLINGO-BODY%3E%3CLINGO-LABS%20id%3D%22lingo-labs-1053461%22%20slang%3D%22en-US%22%3E%3CLINGO-LABEL%3EStorage-Spaces%3C%2FLINGO-LABEL%3E%3C%2FLINGO-LABS%3E
Highlighted
Occasional Visitor

I can't find explanation on how Windows uses columns in Storage Spaces. I have originally thought it works like this:

  • I create pool with parity virtual-disk with 3 columns, 3 drives, giving it capacity of 2 drives or 66 percent efficiency.
  • I add 3 more drives of the same capacity into the pool and extend the virtual-disk, which will again allow me to use additional capacity of the 2 drives I added.

Now I'm getting lost. When I start writing data to this expanded virtual-disk, does it split every write into 2 rows, and every row into 2 columns and then calculates parity for each row? That's what I originally thought, but then Windows asked me to add 2 drives into 3-column parity Storage Space, for a total of 7 drives, which makes no sense to me. What am I missing? How does Storage Spaces write data?

0 Replies