SQLite Forum

vfs write amount size without WAL
A good source of wisdom in this respect is [https://sqlite.org/src/file/ext/misc/cksumvfs.c| The Checksum VFS Shim]. Looking at the xRead and xWrite handlers one can notice that the check-summing logic will go completely out of sync if the requests are not equal to the page size. And for this to happen the implementation ignores (bypasses to the default implementation) anything but main and wal file

  if( (flags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_WAL))==0 ){
    return pSubVfs->xOpen(pSubVfs, zName, pFile, flags, pOutFlags);