You create a 150 GB thick-provisioned volume. In that volume, you create a 50 GB LUN with space-reserve enabled. You create another 50 GB LUN with space-reserve disabled. Before any data is written to

150 GB would only remain available if neither LUN reserved any space, but the space-reserve enabled LUN immediately claims its full 50 GB allocation upon creation.

With a 150 GB thick-provisioned volume, the 50 GB space-reserve enabled LUN immediately claims 50 GB of volume space at creation. The 50 GB space-reserve disabled LUN has no data written and no snapshot exists, so it occupies 0 GB. This leaves exactly 100 GB available for additional LUNs.

75 GB is incorrect because the space-reserve disabled LUN does not consume any volume space before data is written or a snapshot is taken, so only 50 GB is consumed - not 75 GB.

50 GB would be the remaining space only if both LUNs reserved their full 50 GB upfront, but space-reserve disabled means no space is pre-allocated for that LUN.