[petsc-users] Linear system solvers for unsymmetrical matrix

[我]

Hello,
I want to use PETSC to solve an unsymmetrical matrix. I find many linear system 
solvers in PETSC. But I don't know which one is suitable for the unsymmetrical 
matrix. I want to choose the best solver for my problem. Would you mind give me 
some alternative solvers for the unsymmetrical matrix in PETSC?
Thank you very much!
Daye