The HDF5 library contains a cache that provides more efficient access to HDF5 file metadata. Although helpful in most instances, this cache can cause problems when the single-writer/multiple-reader (SWMR) data access pattern is used to access an HDF5 file. Additionally, there are even deeper I/O issues that can affect HDF5 file metadata operations. This document describes the cache-oriented problems that the HDF5 Library must overcome in order to implement the SWMR feature as well as our solutions.