Hello everyone! I am writing a code that uses PETSc/KSP to solve linear systems. I just realized that after running "KSPSolve(...)", the number of iterations given by KSPGetIterationNumber(ksp, &numIts) is *different* from the size of the residual history given by KSPGetResidualHistory(ksp, NULL, &nEntries); That is, "numIts" is not equal to "nEntries". Is this expected, or a bug in my code? (I thought they should be the same...) I have tried several pairs of solvers and preconditioners (e.g., fgmres & bjacobi, ibcgs & bjacobi). This issue happens to all of them. Thanks! Kevin -- Kevin G. Wang, Ph.D. Associate Professor Kevin T. Crofton Department of Aerospace and Ocean Engineering Virginia Tech 1600 Innovation Dr., VTSS Rm 224H, Blacksburg, VA 24061 Office: (540) 231-7547 | Mobile: (650) 862-2663 URL: https://www.aoe.vt.edu/people/faculty/wang.html Codes: https://github.com/kevinwgy