diff --git a/src/addrdb.cpp b/src/addrdb.cpp
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -53,7 +53,9 @@
     if (!SerializeDB(chainParams, fileout, data)) {
         return false;
     }
-    FileCommit(fileout.Get());
+    if (!FileCommit(fileout.Get())) {
+        return error("%s: Failed to flush file %s", __func__, pathTmp.string());
+    }
     fileout.fclose();
 
     // replace existing file, if any, with new file
diff --git a/src/util.h b/src/util.h
--- a/src/util.h
+++ b/src/util.h
@@ -67,7 +67,7 @@
 }
 
 void PrintExceptionContinue(const std::exception *pex, const char *pszThread);
-void FileCommit(FILE *file);
+bool FileCommit(FILE *file);
 bool TruncateFile(FILE *file, unsigned int length);
 int RaiseFileDescriptorLimit(int nMinFD);
 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
diff --git a/src/util.cpp b/src/util.cpp
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -978,21 +978,40 @@
     return false;
 }
 
-void FileCommit(FILE *file) {
-    // Harmless if redundantly called.
-    fflush(file);
+bool FileCommit(FILE *file) {
+    // harmless if redundantly called
+    if (fflush(file) != 0) {
+        LogPrintf("%s: fflush failed: %d\n", __func__, errno);
+        return false;
+    }
 #ifdef WIN32
     HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
-    FlushFileBuffers(hFile);
+    if (FlushFileBuffers(hFile) == 0) {
+        LogPrintf("%s: FlushFileBuffers failed: %d\n", __func__,
+                  GetLastError());
+        return false;
+    }
 #else
 #if defined(__linux__) || defined(__NetBSD__)
-    fdatasync(fileno(file));
+    // Ignore EINVAL for filesystems that don't support sync
+    if (fdatasync(fileno(file)) != 0 && errno != EINVAL) {
+        LogPrintf("%s: fdatasync failed: %d\n", __func__, errno);
+        return false;
+    }
 #elif defined(__APPLE__) && defined(F_FULLFSYNC)
-    fcntl(fileno(file), F_FULLFSYNC, 0);
+    // Manpage says "value other than -1" is returned on success
+    if (fcntl(fileno(file), F_FULLFSYNC, 0) == -1) {
+        LogPrintf("%s: fcntl F_FULLFSYNC failed: %d\n", __func__, errno);
+        return false;
+    }
 #else
-    fsync(fileno(file));
+    if (fsync(fileno(file)) != 0 && errno != EINVAL) {
+        LogPrintf("%s: fsync failed: %d\n", __func__, errno);
+        return false;
+    }
 #endif
 #endif
+    return true;
 }
 
 bool TruncateFile(FILE *file, unsigned int length) {
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1487,24 +1487,32 @@
     LOCK(cs_LastBlockFile);
 
     CDiskBlockPos posOld(nLastBlockFile, 0);
+    bool status = true;
 
     FILE *fileOld = OpenBlockFile(posOld);
     if (fileOld) {
         if (fFinalize) {
-            TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nSize);
+            status &=
+                TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nSize);
         }
-        FileCommit(fileOld);
+        status &= FileCommit(fileOld);
         fclose(fileOld);
     }
 
     fileOld = OpenUndoFile(posOld);
     if (fileOld) {
         if (fFinalize) {
-            TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nUndoSize);
+            status &=
+                TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nUndoSize);
         }
-        FileCommit(fileOld);
+        status &= FileCommit(fileOld);
         fclose(fileOld);
     }
+
+    if (!status) {
+        AbortNode("Flushing block file to disk failed. This is likely the "
+                  "result of an I/O error.");
+    }
 }
 
 static bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos,
@@ -5625,7 +5633,9 @@
         }
 
         file << mapDeltas;
-        FileCommit(file.Get());
+        if (!FileCommit(file.Get())) {
+            throw std::runtime_error("FileCommit failed");
+        }
         file.fclose();
         RenameOver(GetDataDir() / "mempool.dat.new",
                    GetDataDir() / "mempool.dat");