Parallel file systems (PFS’es) and parallel I/O libraries have been the backbone of high- performance computing (HPC) infrastructures for decades. However, their crash consistency bugs have not been extensively studied, and bug-finding or testing tools for identifying them are lacking. In this dissertation, we developed a generic testing system PFSCheck to study crash consistency bugs on popular PFS’es, such as BeeGFS and OrangeFS, with a cross-stack approach that covers HPC I/O library, PFS, and their interactions with local file systems. We evaluated the crash vulnerabilities of common HPC workloads and the evaluation results show that PFS’es and I/O libraries suffer from more crash consistency bugs than regular file systems due to the scale and complexity of the I/O stack. Local file system configurations such as journaling mode and the choice of consistency checker also influence the discovered vulnerability pattern.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste