diff --git a/driver/main.cpp b/driver/main.cpp
index a916854..76a4c93 100644
--- a/driver/main.cpp
+++ b/driver/main.cpp
@@ -40,7 +40,7 @@ int main(int argc, char* argv[])
     logvisor::RegisterConsoleLogger();
 
     nod::ExtractionContext ctx = { true, true, [&](const std::string& str, float c){
-                                       fprintf(stderr, "Current node: %s, Extraction %g%% Complete\n", str.c_str(), c);
+                                       fprintf(stderr, "Current node: %s, Extraction %g%% Complete\n", str.c_str(), c * 100.f);
                                    }};
     const nod::SystemChar* inDir = nullptr;
     const nod::SystemChar* outDir = _S(".");
@@ -58,18 +58,13 @@ int main(int argc, char* argv[])
             outDir = argv[a];
     }
 
-    size_t lastIdx = -1;
-    auto progFunc = [&](size_t idx, const nod::SystemString& name, size_t bytes)
+    auto progFunc = [&](float prog, const nod::SystemString& name, size_t bytes)
     {
-        if (idx != lastIdx)
-        {
-            lastIdx = idx;
-            printf("\n");
-        }
+        nod::Printf(_S("\r                                                            "));
         if (bytes != -1)
-            nod::Printf(_S("\r%s %" PRISize " B"), name.c_str(), bytes);
+            nod::Printf(_S("\r%g%% %s %" PRISize " B"), prog * 100.f, name.c_str(), bytes);
         else
-            nod::Printf(_S("\r%s"), name.c_str());
+            nod::Printf(_S("\r%g%% %s"), prog * 100.f, name.c_str());
         fflush(stdout);
     };
 
@@ -135,7 +130,7 @@ int main(int argc, char* argv[])
         if (nod::DiscBuilderGCN::CalculateTotalSizeRequired(argv[4], argv[5]) == -1)
             return 1;
 
-        bool ret;
+        nod::EBuildResult ret;
 
         if (argc < 8)
         {
@@ -151,7 +146,7 @@ int main(int argc, char* argv[])
         }
 
         printf("\n");
-        if (!ret)
+        if (ret != nod::EBuildResult::Success)
             return 1;
     }
     else if (!strcasecmp(argv[1], _S("makewii")))
@@ -202,7 +197,7 @@ int main(int argc, char* argv[])
         if (nod::DiscBuilderWii::CalculateTotalSizeRequired(argv[4], argv[5], dual) == -1)
             return 1;
 
-        bool ret;
+        nod::EBuildResult ret;
 
         if (argc < 9)
         {
@@ -218,7 +213,7 @@ int main(int argc, char* argv[])
         }
 
         printf("\n");
-        if (!ret)
+        if (ret != nod::EBuildResult::Success)
             return 1;
     }
     else if (!strcasecmp(argv[1], _S("mergegcn")))
@@ -252,7 +247,7 @@ int main(int argc, char* argv[])
         if (nod::DiscMergerGCN::CalculateTotalSizeRequired(static_cast<nod::DiscGCN&>(*disc), argv[2]) == -1)
             return 1;
 
-        bool ret;
+        nod::EBuildResult ret;
 
         if (argc < 5)
         {
@@ -268,7 +263,7 @@ int main(int argc, char* argv[])
         }
 
         printf("\n");
-        if (!ret)
+        if (ret != nod::EBuildResult::Success)
             return 1;
     }
     else if (!strcasecmp(argv[1], _S("mergewii")))
@@ -303,7 +298,7 @@ int main(int argc, char* argv[])
         if (nod::DiscMergerWii::CalculateTotalSizeRequired(static_cast<nod::DiscWii&>(*disc), argv[2], dual) == -1)
             return 1;
 
-        bool ret;
+        nod::EBuildResult ret;
 
         if (argc < 5)
         {
@@ -319,7 +314,7 @@ int main(int argc, char* argv[])
         }
 
         printf("\n");
-        if (!ret)
+        if (ret != nod::EBuildResult::Success)
             return 1;
     }
     else
diff --git a/include/nod/DiscBase.hpp b/include/nod/DiscBase.hpp
index 2bc7780..256c95b 100644
--- a/include/nod/DiscBase.hpp
+++ b/include/nod/DiscBase.hpp
@@ -15,7 +15,14 @@
 namespace nod
 {
 
-using FProgress = std::function<void(size_t, const SystemString&, size_t)>;
+using FProgress = std::function<void(float totalProg, const SystemString& fileName, size_t fileBytesXfered)>;
+
+enum class EBuildResult
+{
+    Success,
+    Failed,
+    DiskFull
+};
 
 class FSTNode
 {
@@ -237,6 +244,18 @@ public:
         uint64_t m_offset;
     public:
         mutable size_t m_curNodeIdx = 0;
+        float getProgressFactor() const { return getNodeCount() ? m_curNodeIdx / float(getNodeCount()) : 0.f; }
+        float getProgressFactorMidFile(size_t curByte, size_t totalBytes) const
+        {
+            if (!getNodeCount())
+                return 0.f;
+
+            if (totalBytes)
+                return (m_curNodeIdx + (curByte / float(totalBytes))) / float(getNodeCount());
+            else
+                return m_curNodeIdx / float(getNodeCount());
+        }
+
         IPartition(const DiscBase& parent, Kind kind, uint64_t offset)
         : m_parent(parent), m_kind(kind), m_offset(offset) {}
         virtual uint64_t normalizeOffset(uint64_t anOffset) const {return anOffset;}
@@ -342,18 +361,25 @@ public:
         size_t m_buildNameOff = 0;
         virtual uint64_t userAllocate(uint64_t reqSz, IPartWriteStream& ws)=0;
         virtual uint32_t packOffset(uint64_t offset) const=0;
+
+        void recursiveBuildNodesPre(const SystemChar* dirIn, uint64_t dolInode);
         bool recursiveBuildNodes(IPartWriteStream& ws, bool system, const SystemChar* dirIn, uint64_t dolInode);
+
         bool recursiveBuildFST(const SystemChar* dirIn, uint64_t dolInode,
                                std::function<void(void)> incParents);
+
+        void recursiveMergeNodesPre(const DiscBase::IPartition::Node* nodeIn, const SystemChar* dirIn);
         bool recursiveMergeNodes(IPartWriteStream& ws, bool system,
                                  const DiscBase::IPartition::Node* nodeIn, const SystemChar* dirIn,
                                  const SystemString& keyPath);
         bool recursiveMergeFST(const DiscBase::IPartition::Node* nodeIn,
                                const SystemChar* dirIn, std::function<void(void)> incParents,
                                const SystemString& keyPath);
+
         static bool RecursiveCalculateTotalSize(uint64_t& totalSz,
                                                 const DiscBase::IPartition::Node* nodeIn,
                                                 const SystemChar* dirIn);
+
         void addBuildName(const SystemString& str)
         {
             SystemUTF8View utf8View(str);
@@ -396,11 +422,26 @@ protected:
     std::vector<std::unique_ptr<PartitionBuilderBase>> m_partitions;
     int64_t m_discCapacity;
 public:
-    std::function<void(size_t idx, const SystemString&, size_t)> m_progressCB;
+    FProgress m_progressCB;
     size_t m_progressIdx = 0;
+    size_t m_progressTotal = 0;
+    float getProgressFactor() const
+    {
+        return m_progressTotal ? std::min(1.f, m_progressIdx / float(m_progressTotal)) : 0.f;
+    }
+    float getProgressFactorMidFile(size_t curByte, size_t totalBytes) const
+    {
+        if (!m_progressTotal)
+            return 0.f;
+
+        if (totalBytes)
+            return (m_progressIdx + (curByte / float(totalBytes))) / float(m_progressTotal);
+        else
+            return m_progressIdx / float(m_progressTotal);
+    }
+
     virtual ~DiscBuilderBase() = default;
-    DiscBuilderBase(const SystemChar* outPath, int64_t discCapacity,
-                    std::function<void(size_t idx, const SystemString&, size_t)> progressCB)
+    DiscBuilderBase(const SystemChar* outPath, int64_t discCapacity, FProgress progressCB)
     : m_outPath(outPath), m_fileIO(NewFileIO(outPath, discCapacity)),
       m_discCapacity(discCapacity), m_progressCB(progressCB) {}
     DiscBuilderBase(DiscBuilderBase&&) = default;
diff --git a/include/nod/DiscGCN.hpp b/include/nod/DiscGCN.hpp
index 5390a3e..6582437 100644
--- a/include/nod/DiscGCN.hpp
+++ b/include/nod/DiscGCN.hpp
@@ -21,8 +21,8 @@ class DiscBuilderGCN : public DiscBuilderBase
 public:
     DiscBuilderGCN(const SystemChar* outPath, const char gameID[6], const char* gameTitle,
                    uint32_t fstMemoryAddr, FProgress progressCB);
-    bool buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
-                            const SystemChar* apploaderIn);
+    EBuildResult buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
+                                    const SystemChar* apploaderIn);
     static uint64_t CalculateTotalSizeRequired(const SystemChar* dirIn, const SystemChar* dolIn);
 };
 
@@ -32,7 +32,7 @@ class DiscMergerGCN
     DiscBuilderGCN m_builder;
 public:
     DiscMergerGCN(const SystemChar* outPath, DiscGCN& sourceDisc, FProgress progressCB);
-    bool mergeFromDirectory(const SystemChar* dirIn);
+    EBuildResult mergeFromDirectory(const SystemChar* dirIn);
     static uint64_t CalculateTotalSizeRequired(DiscGCN& sourceDisc, const SystemChar* dirIn);
 };
 
diff --git a/include/nod/DiscWii.hpp b/include/nod/DiscWii.hpp
index 5cbcc2e..a6a0547 100644
--- a/include/nod/DiscWii.hpp
+++ b/include/nod/DiscWii.hpp
@@ -21,10 +21,10 @@ class DiscBuilderWii : public DiscBuilderBase
 public:
     DiscBuilderWii(const SystemChar* outPath, const char gameID[6], const char* gameTitle,
                    bool dualLayer, FProgress progressCB);
-    bool buildFromDirectory(const SystemChar* dirIn,
-                            const SystemChar* dolIn,
-                            const SystemChar* apploaderIn,
-                            const SystemChar* partHeadIn);
+    EBuildResult buildFromDirectory(const SystemChar* dirIn,
+                                    const SystemChar* dolIn,
+                                    const SystemChar* apploaderIn,
+                                    const SystemChar* partHeadIn);
     static uint64_t CalculateTotalSizeRequired(const SystemChar* dirIn, const SystemChar* dolIn,
                                                bool& dualLayer);
 };
@@ -36,7 +36,7 @@ class DiscMergerWii
 public:
     DiscMergerWii(const SystemChar* outPath, DiscWii& sourceDisc,
                   bool dualLayer, FProgress progressCB);
-    bool mergeFromDirectory(const SystemChar* dirIn);
+    EBuildResult mergeFromDirectory(const SystemChar* dirIn);
     static uint64_t CalculateTotalSizeRequired(DiscWii& sourceDisc, const SystemChar* dirIn,
                                                bool& dualLayer);
 };
diff --git a/include/nod/IFileIO.hpp b/include/nod/IFileIO.hpp
index 009c1c9..31f89fb 100644
--- a/include/nod/IFileIO.hpp
+++ b/include/nod/IFileIO.hpp
@@ -20,7 +20,55 @@ public:
     {
         virtual ~IWriteStream() {}
         virtual uint64_t write(const void* buf, uint64_t length)=0;
-        virtual uint64_t copyFromDisc(struct IPartReadStream& discio, uint64_t length)=0;
+
+        uint64_t copyFromDisc(IPartReadStream& discio, uint64_t length)
+        {
+            uint64_t read = 0;
+            uint8_t buf[0x7c00];
+            while (length)
+            {
+                uint64_t thisSz = nod::min(uint64_t(0x7c00), length);
+                uint64_t readSz = discio.read(buf, thisSz);
+                if (thisSz != readSz)
+                {
+                    LogModule.report(logvisor::Error, "unable to read enough from disc");
+                    return read;
+                }
+                if (write(buf, readSz) != readSz)
+                {
+                    LogModule.report(logvisor::Error, "unable to write in file");
+                    return read;
+                }
+                length -= thisSz;
+                read += thisSz;
+            }
+            return read;
+        }
+        uint64_t copyFromDisc(IPartReadStream& discio, uint64_t length, const std::function<void(float)>& prog)
+        {
+            uint64_t read = 0;
+            uint8_t buf[0x7c00];
+            uint64_t total = length;
+            while (length)
+            {
+                uint64_t thisSz = nod::min(uint64_t(0x7c00), length);
+                uint64_t readSz = discio.read(buf, thisSz);
+                if (thisSz != readSz)
+                {
+                    LogModule.report(logvisor::Error, "unable to read enough from disc");
+                    return read;
+                }
+                if (write(buf, readSz) != readSz)
+                {
+                    LogModule.report(logvisor::Error, "unable to write in file");
+                    return read;
+                }
+                length -= thisSz;
+                read += thisSz;
+                prog(read / float(total));
+            }
+            return read;
+        }
     };
     virtual std::unique_ptr<IWriteStream> beginWriteStream() const=0;
     virtual std::unique_ptr<IWriteStream> beginWriteStream(uint64_t offset) const=0;
diff --git a/lib/DiscBase.cpp b/lib/DiscBase.cpp
index be79386..ceb4ca0 100644
--- a/lib/DiscBase.cpp
+++ b/lib/DiscBase.cpp
@@ -99,7 +99,7 @@ bool DiscBase::IPartition::Node::extractToDirectory(const SystemString& basePath
     {
         ++m_parent.m_curNodeIdx;
         if (ctx.verbose && ctx.progressCB && !getName().empty())
-            ctx.progressCB(getName(), float(m_parent.m_curNodeIdx * 100.f)  / m_parent.getNodeCount());
+            ctx.progressCB(getName(), m_parent.m_curNodeIdx / float(m_parent.getNodeCount()));
         if (Mkdir(path.c_str(), 0755) && errno != EEXIST)
         {
             LogModule.report(logvisor::Error, _S("unable to mkdir '%s'"), path.c_str());
@@ -112,9 +112,8 @@ bool DiscBase::IPartition::Node::extractToDirectory(const SystemString& basePath
     else if (m_kind == Kind::File)
     {
         Sstat theStat;
-        ++m_parent.m_curNodeIdx;
         if (ctx.verbose && ctx.progressCB)
-            ctx.progressCB(getName(), float(m_parent.m_curNodeIdx * 100.f)  / m_parent.getNodeCount());
+            ctx.progressCB(getName(), m_parent.m_curNodeIdx / float(m_parent.getNodeCount()));
 
         if (ctx.force || Stat(path.c_str(), &theStat))
         {
@@ -122,8 +121,14 @@ bool DiscBase::IPartition::Node::extractToDirectory(const SystemString& basePath
             std::unique_ptr<IFileIO::IWriteStream> ws = NewFileIO(path)->beginWriteStream();
             if (!rs || !ws)
                 return false;
-            ws->copyFromDisc(*rs, m_discLength);
+            ws->copyFromDisc(*rs, m_discLength,
+            [&](float prog)
+            {
+                if (ctx.verbose && ctx.progressCB)
+                    ctx.progressCB(getName(), (m_parent.m_curNodeIdx + prog) / float(m_parent.getNodeCount()));
+            });
         }
+        ++m_parent.m_curNodeIdx;
     }
     return true;
 }
@@ -263,6 +268,26 @@ static size_t PatchDOL(IFileIO::IReadStream& in, IPartWriteStream& out, size_t s
     return out.write(buf.get(), sz);
 }
 
+void DiscBuilderBase::PartitionBuilderBase::recursiveBuildNodesPre(const SystemChar* dirIn,
+                                                                   uint64_t dolInode)
+{
+    DirectoryEnumerator dEnum(dirIn, DirectoryEnumerator::Mode::DirsThenFilesSorted, false, false, true);
+    for (const DirectoryEnumerator::Entry& e : dEnum)
+    {
+        if (e.m_isDir)
+        {
+            recursiveBuildNodesPre(e.m_path.c_str(), dolInode);
+        }
+        else
+        {
+            if (dolInode == GetInode(e.m_path.c_str()))
+                continue;
+
+            ++m_parent.m_progressTotal;
+        }
+    }
+}
+
 bool DiscBuilderBase::PartitionBuilderBase::recursiveBuildNodes(IPartWriteStream& ws,
                                                                 bool system,
                                                                 const SystemChar* dirIn,
@@ -299,12 +324,12 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveBuildNodes(IPartWriteStream
             {
                 bool patched;
                 xferSz = PatchDOL(*rs, ws, e.m_fileSz, patched);
-                m_parent.m_progressCB(++m_parent.m_progressIdx, e.m_name + (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+                m_parent.m_progressCB(m_parent.getProgressFactor(), e.m_name + (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+                ++m_parent.m_progressIdx;
             }
             else
             {
                 char buf[0x8000];
-                ++m_parent.m_progressIdx;
                 while (xferSz < e.m_fileSz)
                 {
                     size_t rdSz = rs->read(buf, nod::min(size_t(0x8000ul), e.m_fileSz - xferSz));
@@ -312,8 +337,9 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveBuildNodes(IPartWriteStream
                         break;
                     ws.write(buf, rdSz);
                     xferSz += rdSz;
-                    m_parent.m_progressCB(m_parent.m_progressIdx, e.m_name, xferSz);
+                    m_parent.m_progressCB(m_parent.getProgressFactorMidFile(xferSz, e.m_fileSz), e.m_name, xferSz);
                 }
+                ++m_parent.m_progressIdx;
             }
             for (size_t i=0 ; i<fileSz-xferSz ; ++i)
                 ws.write("\xff", 1);
@@ -358,6 +384,64 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveBuildFST(const SystemChar*
     return true;
 }
 
+void DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodesPre(const DiscBase::IPartition::Node* nodeIn,
+                                                                   const SystemChar* dirIn)
+{
+    /* Build map of existing nodes to write-through later */
+    std::unordered_map<std::string, const Partition::Node*> fileNodes;
+    std::unordered_map<std::string, const Partition::Node*> dirNodes;
+    if (nodeIn)
+    {
+        fileNodes.reserve(nodeIn->size());
+        dirNodes.reserve(nodeIn->size());
+        for (const Partition::Node& ch : *nodeIn)
+        {
+            if (ch.getKind() == Partition::Node::Kind::File)
+                fileNodes.insert(std::make_pair(ch.getName(), &ch));
+            else if (ch.getKind() == Partition::Node::Kind::Directory)
+                dirNodes.insert(std::make_pair(ch.getName(), &ch));
+        }
+    }
+
+    /* Merge this directory's files */
+    if (dirIn)
+    {
+        DirectoryEnumerator dEnum(dirIn, DirectoryEnumerator::Mode::DirsThenFilesSorted, false, false, true);
+        for (const DirectoryEnumerator::Entry& e : dEnum)
+        {
+            SystemUTF8View nameView(e.m_name);
+
+            if (e.m_isDir)
+            {
+                auto search = dirNodes.find(nameView.utf8_str());
+                if (search != dirNodes.cend())
+                {
+                    recursiveMergeNodesPre(search->second, e.m_path.c_str());
+                    dirNodes.erase(search);
+                }
+                else
+                {
+                    recursiveMergeNodesPre(nullptr, e.m_path.c_str());
+                }
+            }
+            else
+            {
+                fileNodes.erase(nameView.utf8_str());
+                ++m_parent.m_progressTotal;
+            }
+        }
+    }
+
+    /* Write-through remaining dir nodes */
+    for (const auto& p : dirNodes)
+    {
+        recursiveMergeNodesPre(p.second, nullptr);
+    }
+
+    /* Write-through remaining file nodes */
+    m_parent.m_progressTotal += fileNodes.size();
+}
+
 bool DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodes(IPartWriteStream& ws,
                                                                 bool system,
                                                                 const DiscBase::IPartition::Node* nodeIn,
@@ -426,13 +510,13 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodes(IPartWriteStream
                 {
                     bool patched;
                     xferSz = PatchDOL(*rs, ws, e.m_fileSz, patched);
-                    m_parent.m_progressCB(++m_parent.m_progressIdx, e.m_name +
+                    m_parent.m_progressCB(m_parent.getProgressFactor(), e.m_name +
                                           (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+                    ++m_parent.m_progressIdx;
                 }
                 else
                 {
                     char buf[0x8000];
-                    ++m_parent.m_progressIdx;
                     while (xferSz < e.m_fileSz)
                     {
                         size_t rdSz = rs->read(buf, nod::min(size_t(0x8000ul), e.m_fileSz - xferSz));
@@ -440,8 +524,9 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodes(IPartWriteStream
                             break;
                         ws.write(buf, rdSz);
                         xferSz += rdSz;
-                        m_parent.m_progressCB(m_parent.m_progressIdx, e.m_name, xferSz);
+                        m_parent.m_progressCB(m_parent.getProgressFactorMidFile(xferSz, e.m_fileSz), e.m_name, xferSz);
                     }
+                    ++m_parent.m_progressIdx;
                 }
                 for (size_t i=0 ; i<fileSz-xferSz ; ++i)
                     ws.write("\xff", 1);
@@ -486,13 +571,13 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodes(IPartWriteStream
             bool patched;
             PatchDOL(dolBuf, xferSz, patched);
             ws.write(dolBuf.get(), xferSz);
-            m_parent.m_progressCB(++m_parent.m_progressIdx, sysName.sys_str() +
+            m_parent.m_progressCB(m_parent.getProgressFactor(), sysName.sys_str() +
                                   (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+            ++m_parent.m_progressIdx;
         }
         else
         {
             char buf[0x8000];
-            ++m_parent.m_progressIdx;
             while (xferSz < ch.size())
             {
                 size_t rdSz = rs->read(buf, nod::min(size_t(0x8000), size_t(ch.size() - xferSz)));
@@ -500,8 +585,9 @@ bool DiscBuilderBase::PartitionBuilderBase::recursiveMergeNodes(IPartWriteStream
                     break;
                 ws.write(buf, rdSz);
                 xferSz += rdSz;
-                m_parent.m_progressCB(m_parent.m_progressIdx, sysName.sys_str(), xferSz);
+                m_parent.m_progressCB(m_parent.getProgressFactorMidFile(xferSz, ch.size()), sysName.sys_str(), xferSz);
             }
+            ++m_parent.m_progressIdx;
         }
         for (size_t i=0 ; i<fileSz-xferSz ; ++i)
             ws.write("\xff", 1);
@@ -689,9 +775,14 @@ bool DiscBuilderBase::PartitionBuilderBase::buildFromDirectory(IPartWriteStream&
         return false;
     }
 
+    /* 1st pass - Tally up total progress steps */
+    uint64_t dolInode = GetInode(dolIn);
+    m_parent.m_progressTotal += 2; /* Prep and DOL */
+    recursiveBuildNodesPre(dirIn, dolInode);
+
     /* Clear file */
+    m_parent.m_progressCB(m_parent.getProgressFactor(), _S("Preparing output image"), -1);
     ++m_parent.m_progressIdx;
-    m_parent.m_progressCB(m_parent.m_progressIdx, _S("Preparing output image"), -1);
 
     /* Add root node */
     m_buildNodes.emplace_back(true, m_buildNameOff, 0, 1);
@@ -716,14 +807,14 @@ bool DiscBuilderBase::PartitionBuilderBase::buildFromDirectory(IPartWriteStream&
             return false;
         bool patched;
         size_t xferSz = PatchDOL(*rs, ws, dolStat.st_size, patched);
-        m_parent.m_progressCB(++m_parent.m_progressIdx, SystemString(dolIn) +
+        m_parent.m_progressCB(m_parent.getProgressFactor(), SystemString(dolIn) +
                               (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+        ++m_parent.m_progressIdx;
         for (size_t i=0 ; i<fileSz-xferSz ; ++i)
             ws.write("\xff", 1);
     }
 
     /* Gather files in root directory */
-    uint64_t dolInode = GetInode(dolIn);
     if (!recursiveBuildNodes(ws, true, dirIn, dolInode))
         return false;
     if (!recursiveBuildNodes(ws, false, dirIn, dolInode))
@@ -759,9 +850,13 @@ bool DiscBuilderBase::PartitionBuilderBase::mergeFromDirectory(IPartWriteStream&
         return false;
     }
 
+    /* 1st pass - Tally up total progress steps */
+    m_parent.m_progressTotal += 2; /* Prep and DOL */
+    recursiveMergeNodesPre(&partIn->getFSTRoot(), dirIn);
+
     /* Clear file */
+    m_parent.m_progressCB(m_parent.getProgressFactor(), _S("Preparing output image"), -1);
     ++m_parent.m_progressIdx;
-    m_parent.m_progressCB(m_parent.m_progressIdx, _S("Preparing output image"), -1);
 
     /* Add root node */
     m_buildNodes.emplace_back(true, m_buildNameOff, 0, 1);
@@ -780,8 +875,9 @@ bool DiscBuilderBase::PartitionBuilderBase::mergeFromDirectory(IPartWriteStream&
         bool patched;
         PatchDOL(dolBuf, xferSz, patched);
         ws.write(dolBuf.get(), xferSz);
-        m_parent.m_progressCB(++m_parent.m_progressIdx, SystemString(_S("<boot-dol>")) +
+        m_parent.m_progressCB(m_parent.getProgressFactor(), SystemString(_S("<boot-dol>")) +
                               (patched ? _S(" [PATCHED]") : _S("")), xferSz);
+        ++m_parent.m_progressIdx;
         for (size_t i=0 ; i<fileSz-xferSz ; ++i)
             ws.write("\xff", 1);
     }
diff --git a/lib/DiscGCN.cpp b/lib/DiscGCN.cpp
index 890a32e..6539b6b 100644
--- a/lib/DiscGCN.cpp
+++ b/lib/DiscGCN.cpp
@@ -264,7 +264,6 @@ public:
                 return false;
             char buf[8192];
             SystemString apploaderName(apploaderIn);
-            ++m_parent.m_progressIdx;
             while (true)
             {
                 size_t rdSz = rs->read(buf, 8192);
@@ -278,8 +277,9 @@ public:
                                      "apploader flows into user area (one or the other is too big)");
                     return false;
                 }
-                m_parent.m_progressCB(m_parent.m_progressIdx, apploaderName, xferSz);
+                m_parent.m_progressCB(m_parent.getProgressFactor(), apploaderName, xferSz);
             }
+            ++m_parent.m_progressIdx;
             return true;
         });
     }
@@ -298,7 +298,6 @@ public:
             std::unique_ptr<uint8_t[]> apploaderBuf = partIn->getApploaderBuf();
             size_t apploaderSz = partIn->getApploaderSize();
             SystemString apploaderName(_S("<apploader>"));
-            ++m_parent.m_progressIdx;
             ws.write(apploaderBuf.get(), apploaderSz);
             xferSz += apploaderSz;
             if (0x2440 + xferSz >= m_curUser)
@@ -307,31 +306,32 @@ public:
                                  "apploader flows into user area (one or the other is too big)");
                 return false;
             }
-            m_parent.m_progressCB(m_parent.m_progressIdx, apploaderName, xferSz);
+            m_parent.m_progressCB(m_parent.getProgressFactor(), apploaderName, xferSz);
+            ++m_parent.m_progressIdx;
             return true;
         });
     }
 };
 
-bool DiscBuilderGCN::buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
-                                        const SystemChar* apploaderIn)
+EBuildResult DiscBuilderGCN::buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
+                                                const SystemChar* apploaderIn)
 {
     if (!m_fileIO->beginWriteStream())
-        return false;
+        return EBuildResult::Failed;
     if (!CheckFreeSpace(m_outPath.c_str(), 0x57058000))
     {
         LogModule.report(logvisor::Error, _S("not enough free disk space for %s"), m_outPath.c_str());
-        return false;
+        return EBuildResult::DiskFull;
     }
+    m_progressCB(getProgressFactor(), _S("Preallocating image"), -1);
     ++m_progressIdx;
-    m_progressCB(m_progressIdx, _S("Preallocating image"), -1);
     auto ws = m_fileIO->beginWriteStream(0x57058000 - 1);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     ws->write("", 1);
 
     PartitionBuilderGCN& pb = static_cast<PartitionBuilderGCN&>(*m_partitions[0]);
-    return pb.buildFromDirectory(dirIn, dolIn, apploaderIn);
+    return pb.buildFromDirectory(dirIn, dolIn, apploaderIn) ? EBuildResult::Success : EBuildResult::Failed;
 }
 
 uint64_t DiscBuilderGCN::CalculateTotalSizeRequired(const SystemChar* dirIn, const SystemChar* dolIn)
@@ -361,24 +361,25 @@ DiscMergerGCN::DiscMergerGCN(const SystemChar* outPath, DiscGCN& sourceDisc, FPr
 : m_sourceDisc(sourceDisc), m_builder(sourceDisc.makeMergeBuilder(outPath, progressCB))
 {}
 
-bool DiscMergerGCN::mergeFromDirectory(const SystemChar* dirIn)
+EBuildResult DiscMergerGCN::mergeFromDirectory(const SystemChar* dirIn)
 {
     if (!m_builder.getFileIO().beginWriteStream())
-        return false;
+        return EBuildResult::Failed;
     if (!CheckFreeSpace(m_builder.m_outPath.c_str(), 0x57058000))
     {
         LogModule.report(logvisor::Error, _S("not enough free disk space for %s"), m_builder.m_outPath.c_str());
-        return false;
+        return EBuildResult::DiskFull;
     }
+    m_builder.m_progressCB(m_builder.getProgressFactor(), _S("Preallocating image"), -1);
     ++m_builder.m_progressIdx;
-    m_builder.m_progressCB(m_builder.m_progressIdx, _S("Preallocating image"), -1);
     auto ws = m_builder.m_fileIO->beginWriteStream(0x57058000 - 1);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     ws->write("", 1);
 
     PartitionBuilderGCN& pb = static_cast<PartitionBuilderGCN&>(*m_builder.m_partitions[0]);
-    return pb.mergeFromDirectory(static_cast<PartitionGCN*>(m_sourceDisc.getDataPartition()), dirIn);
+    return pb.mergeFromDirectory(static_cast<PartitionGCN*>(m_sourceDisc.getDataPartition()), dirIn) ?
+           EBuildResult::Success : EBuildResult::Failed;
 }
 
 uint64_t DiscMergerGCN::CalculateTotalSizeRequired(DiscGCN& sourceDisc, const SystemChar* dirIn)
diff --git a/lib/DiscWii.cpp b/lib/DiscWii.cpp
index 8a4b522..990e549 100644
--- a/lib/DiscWii.cpp
+++ b/lib/DiscWii.cpp
@@ -928,7 +928,6 @@ public:
         bool good = false;
         uint64_t attempts = 0;
         SystemString bfName(_S("Brute force attempts"));
-        ++m_parent.m_progressIdx;
         for (int w=0 ; w<7 ; ++w)
         {
             for (uint64_t i=0 ; i<UINT64_MAX ; ++i)
@@ -943,12 +942,13 @@ public:
                     good = true;
                     break;
                 }
-                m_parent.m_progressCB(m_parent.m_progressIdx, bfName, attempts);
+                m_parent.m_progressCB(m_parent.getProgressFactor(), bfName, attempts);
             }
             if (good)
                 break;
         }
-        m_parent.m_progressCB(m_parent.m_progressIdx, bfName, attempts);
+        m_parent.m_progressCB(m_parent.getProgressFactor(), bfName, attempts);
+        ++m_parent.m_progressIdx;
 
         ws = m_parent.getFileIO().beginWriteStream(m_baseOffset + 0x2C0);
         if (!ws)
@@ -994,7 +994,6 @@ public:
                 return false;
             char buf[8192];
             SystemString apploaderName(apploaderIn);
-            ++m_parent.m_progressIdx;
             while (true)
             {
                 size_t rdSz = rs->read(buf, 8192);
@@ -1008,8 +1007,9 @@ public:
                                      "apploader flows into user area (one or the other is too big)");
                     return false;
                 }
-                m_parent.m_progressCB(m_parent.m_progressIdx, apploaderName, xferSz);
+                m_parent.m_progressCB(m_parent.getProgressFactor(), apploaderName, xferSz);
             }
+            ++m_parent.m_progressIdx;
             return true;
         }, phBuf.get(), phSz, theStat.st_size);
     }
@@ -1030,7 +1030,6 @@ public:
             std::unique_ptr<uint8_t[]> apploaderBuf = partIn->getApploaderBuf();
             size_t apploaderSz = partIn->getApploaderSize();
             SystemString apploaderName(_S("<apploader>"));
-            ++m_parent.m_progressIdx;
             cws.write(apploaderBuf.get(), apploaderSz);
             xferSz += apploaderSz;
             if (0x2440 + xferSz >= 0x1F0000)
@@ -1039,69 +1038,70 @@ public:
                                  "apploader flows into user area (one or the other is too big)");
                 return false;
             }
-            m_parent.m_progressCB(m_parent.m_progressIdx, apploaderName, xferSz);
+            m_parent.m_progressCB(m_parent.getProgressFactor(), apploaderName, xferSz);
+            ++m_parent.m_progressIdx;
             return true;
         }, phBuf.get(), phSz, partIn->getApploaderSize());
     }
 };
 
-bool DiscBuilderWii::buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
-                                        const SystemChar* apploaderIn, const SystemChar* partHeadIn)
+EBuildResult DiscBuilderWii::buildFromDirectory(const SystemChar* dirIn, const SystemChar* dolIn,
+                                                const SystemChar* apploaderIn, const SystemChar* partHeadIn)
 {
     PartitionBuilderWii& pb = static_cast<PartitionBuilderWii&>(*m_partitions[0]);
     uint64_t filledSz = pb.m_baseOffset;
     if (!m_fileIO->beginWriteStream())
-        return false;
+        return EBuildResult::Failed;
 
     if (!CheckFreeSpace(m_outPath.c_str(), m_discCapacity))
     {
         LogModule.report(logvisor::Error, _S("not enough free disk space for %s"), m_outPath.c_str());
-        return false;
+        return EBuildResult::DiskFull;
     }
+    m_progressCB(getProgressFactor(), _S("Preallocating image"), -1);
     ++m_progressIdx;
-    m_progressCB(m_progressIdx, _S("Preallocating image"), -1);
     std::unique_ptr<IFileIO::IWriteStream> ws = m_fileIO->beginWriteStream(m_discCapacity - 1);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     ws->write("", 1);
 
     /* Assemble image */
     filledSz = pb.buildFromDirectory(dirIn, dolIn, apploaderIn, partHeadIn);
     if (filledSz == -1)
-        return false;
+        return EBuildResult::Failed;
     else if (filledSz >= uint64_t(m_discCapacity))
     {
         LogModule.report(logvisor::Error, "data partition exceeds disc capacity");
-        return false;
+        return EBuildResult::Failed;
     }
 
+    m_progressCB(getProgressFactor(), _S("Finishing Disc"), -1);
     ++m_progressIdx;
-    m_progressCB(m_progressIdx, _S("Finishing Disc"), -1);
 
     /* Populate disc header */
     ws = m_fileIO->beginWriteStream(0);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     Header header(pb.getGameID(), pb.getGameTitle().c_str(), true, 0, 0, 0);
     header.write(*ws);
 
     /* Populate partition info */
     ws = m_fileIO->beginWriteStream(0x40000);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     uint32_t vals[2] = {SBig(uint32_t(1)), SBig(uint32_t(0x40020 >> uint64_t(2)))};
     ws->write(vals, 8);
 
     ws = m_fileIO->beginWriteStream(0x40020);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     vals[0] = SBig(uint32_t(pb.m_baseOffset >> uint64_t(2)));
     ws->write(vals, 4);
 
     /* Populate region info */
     ws = m_fileIO->beginWriteStream(0x4E000);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     const char* gameID = pb.getGameID();
     if (gameID[3] == 'P')
         vals[0] = SBig(uint32_t(2));
@@ -1114,14 +1114,14 @@ bool DiscBuilderWii::buildFromDirectory(const SystemChar* dirIn, const SystemCha
     /* Make disc unrated */
     ws = m_fileIO->beginWriteStream(0x4E010);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     for (int i=0 ; i<16 ; ++i)
         ws->write("\x80", 1);
 
     /* Fill image to end */
     ws = m_fileIO->beginWriteStream(filledSz);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     uint8_t fillBuf[512];
     memset(fillBuf, 0xff, 512);
     for (size_t i=m_discCapacity-filledSz ; i>0 ;)
@@ -1136,7 +1136,7 @@ bool DiscBuilderWii::buildFromDirectory(const SystemChar* dirIn, const SystemCha
         break;
     }
 
-    return true;
+    return EBuildResult::Success;
 }
 
 uint64_t DiscBuilderWii::CalculateTotalSizeRequired(const SystemChar* dirIn, const SystemChar* dolIn,
@@ -1172,61 +1172,61 @@ DiscMergerWii::DiscMergerWii(const SystemChar* outPath, DiscWii& sourceDisc,
 : m_sourceDisc(sourceDisc), m_builder(sourceDisc.makeMergeBuilder(outPath, dualLayer, progressCB))
 {}
 
-bool DiscMergerWii::mergeFromDirectory(const SystemChar* dirIn)
+EBuildResult DiscMergerWii::mergeFromDirectory(const SystemChar* dirIn)
 {
     PartitionBuilderWii& pb = static_cast<PartitionBuilderWii&>(*m_builder.m_partitions[0]);
     uint64_t filledSz = pb.m_baseOffset;
     if (!m_builder.m_fileIO->beginWriteStream())
-        return false;
+        return EBuildResult::Failed;
 
     if (!CheckFreeSpace(m_builder.m_outPath.c_str(), m_builder.m_discCapacity))
     {
         LogModule.report(logvisor::Error, _S("not enough free disk space for %s"), m_builder.m_outPath.c_str());
-        return false;
+        return EBuildResult::DiskFull;
     }
+    m_builder.m_progressCB(m_builder.getProgressFactor(), _S("Preallocating image"), -1);
     ++m_builder.m_progressIdx;
-    m_builder.m_progressCB(m_builder.m_progressIdx, _S("Preallocating image"), -1);
     std::unique_ptr<IFileIO::IWriteStream> ws = m_builder.m_fileIO->beginWriteStream(m_builder.m_discCapacity - 1);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     ws->write("", 1);
 
     /* Assemble image */
     filledSz = pb.mergeFromDirectory(static_cast<PartitionWii*>(m_sourceDisc.getDataPartition()), dirIn);
     if (filledSz == -1)
-        return false;
+        return EBuildResult::Failed;
     else if (filledSz >= uint64_t(m_builder.m_discCapacity))
     {
         LogModule.report(logvisor::Error, "data partition exceeds disc capacity");
-        return false;
+        return EBuildResult::Failed;
     }
 
+    m_builder.m_progressCB(m_builder.getProgressFactor(), _S("Finishing Disc"), -1);
     ++m_builder.m_progressIdx;
-    m_builder.m_progressCB(m_builder.m_progressIdx, _S("Finishing Disc"), -1);
 
     /* Populate disc header */
     ws = m_builder.m_fileIO->beginWriteStream(0);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     m_sourceDisc.getHeader().write(*ws);
 
     /* Populate partition info */
     ws = m_builder.m_fileIO->beginWriteStream(0x40000);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     uint32_t vals[2] = {SBig(uint32_t(1)), SBig(uint32_t(0x40020 >> uint64_t(2)))};
     ws->write(vals, 8);
 
     ws = m_builder.m_fileIO->beginWriteStream(0x40020);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     vals[0] = SBig(uint32_t(pb.m_baseOffset >> uint64_t(2)));
     ws->write(vals, 4);
 
     /* Populate region info */
     ws = m_builder.m_fileIO->beginWriteStream(0x4E000);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     const char* gameID = pb.getGameID();
     if (gameID[3] == 'P')
         vals[0] = SBig(uint32_t(2));
@@ -1239,14 +1239,14 @@ bool DiscMergerWii::mergeFromDirectory(const SystemChar* dirIn)
     /* Make disc unrated */
     ws = m_builder.m_fileIO->beginWriteStream(0x4E010);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     for (int i=0 ; i<16 ; ++i)
         ws->write("\x80", 1);
 
     /* Fill image to end */
     ws = m_builder.m_fileIO->beginWriteStream(filledSz);
     if (!ws)
-        return false;
+        return EBuildResult::Failed;
     uint8_t fillBuf[512];
     memset(fillBuf, 0xff, 512);
     for (size_t i=m_builder.m_discCapacity-filledSz ; i>0 ;)
@@ -1261,7 +1261,7 @@ bool DiscMergerWii::mergeFromDirectory(const SystemChar* dirIn)
         break;
     }
 
-    return true;
+    return EBuildResult::Success;
 }
 
 uint64_t DiscMergerWii::CalculateTotalSizeRequired(DiscWii& sourceDisc,
diff --git a/lib/FileIOFILE.cpp b/lib/FileIOFILE.cpp
index 7e7813b..56b3f14 100644
--- a/lib/FileIOFILE.cpp
+++ b/lib/FileIOFILE.cpp
@@ -83,29 +83,6 @@ public:
             }
             return fwrite(buf, 1, length, fp);
         }
-        uint64_t copyFromDisc(IPartReadStream& discio, uint64_t length)
-        {
-            uint64_t read = 0;
-            uint8_t buf[0x7c00];
-            while (length)
-            {
-                uint64_t thisSz = nod::min(uint64_t(0x7c00), length);
-                uint64_t readSz = discio.read(buf, thisSz);
-                if (thisSz != readSz)
-                {
-                    LogModule.report(logvisor::Error, "unable to read enough from disc");
-                    return read;
-                }
-                if (write(buf, readSz) != readSz)
-                {
-                    LogModule.report(logvisor::Error, "unable to write in file");
-                    return read;
-                }
-                length -= thisSz;
-                read += thisSz;
-            }
-            return read;
-        }
     };
     std::unique_ptr<IWriteStream> beginWriteStream() const
     {
diff --git a/lib/FileIOWin32.cpp b/lib/FileIOWin32.cpp
index 57e182d..776af56 100644
--- a/lib/FileIOWin32.cpp
+++ b/lib/FileIOWin32.cpp
@@ -95,29 +95,6 @@ public:
             WriteFile(fp, buf, length, &ret, nullptr);
             return ret;
         }
-        uint64_t copyFromDisc(IPartReadStream& discio, uint64_t length)
-        {
-            uint64_t read = 0;
-            uint8_t buf[0x7c00];
-            while (length)
-            {
-                uint64_t thisSz = nod::min(uint64_t(0x7c00), length);
-                uint64_t readSz = discio.read(buf, thisSz);
-                if (thisSz != readSz)
-                {
-                    LogModule.report(logvisor::Error, "unable to read enough from disc");
-                    return read;
-                }
-                if (write(buf, readSz) != readSz)
-                {
-                    LogModule.report(logvisor::Error, "unable to write in file");
-                    return read;
-                }
-                length -= thisSz;
-                read += thisSz;
-            }
-            return read;
-        }
     };
     std::unique_ptr<IWriteStream> beginWriteStream() const
     {