aspect ratio for solid element & working directory

Hello,

I am trying to find some document regarding the best aspect ratio for solid element

Due to limitation of computing power, I could only get the ratio for my model as small as 2, is it ok?

One more thing, although I set my working directory in another drive (D) different from C drive, I get this error message

Error in job run-E-27000: An error occurred during a write access to C:\\Users\\a1171622\\AppData\\Local\\Temp\\a1171622_run-E-27000_3992\\run-E-27000_stdSolver.local_0 file. Check the disk space on your system.

Why is it running on C drive, which does not have enough disk space?

Is it possible to make abaqus running on different drive?

Regards