diff --git a/src/backend/corebackenddevice.h b/src/backend/corebackenddevice.h
index 600adc6..b3c3126 100644
--- a/src/backend/corebackenddevice.h
+++ b/src/backend/corebackenddevice.h
@@ -91,23 +91,6 @@ public:
       */
     virtual bool createPartitionTable(Report& report, const PartitionTable& ptable) = 0;
 
-    /**
-      * Read data from an opened device into a buffer.
-      * @param buffer the buffer to write the read data to
-      * @param offset offset byte where to start reading on the device
-      * @param size the number of bytes to read
-      * @return true on success
-      */
-    virtual bool readData(QByteArray& buffer, qint64 offset, qint64 size) = 0;
-
-    /**
-      * Write data from a buffer to an exclusively opened device.
-      * @param buffer the buffer with the data
-      * @param offset offset byte where to start writing to the device
-      * @return true on success
-      */
-    virtual bool writeData(QByteArray& buffer, qint64 offset) = 0;
-
 protected:
     void setExclusive(bool b) {
         m_Exclusive = b;
diff --git a/src/core/copysource.h b/src/core/copysource.h
index 3f25e7f..f8f36b2 100644
--- a/src/core/copysource.h
+++ b/src/core/copysource.h
@@ -43,7 +43,6 @@ protected:
 public:
     virtual bool open() = 0;
     virtual QString path() const = 0;
-    virtual bool readData(QByteArray& buffer, qint64 readOffset, qint64 size) = 0;
     virtual qint64 length() const = 0;
     virtual bool overlaps(const CopyTarget& target) const = 0;
 
diff --git a/src/core/copysourcedevice.cpp b/src/core/copysourcedevice.cpp
index 3b91744..9754a0d 100644
--- a/src/core/copysourcedevice.cpp
+++ b/src/core/copysourcedevice.cpp
@@ -63,22 +63,6 @@ qint64 CopySourceDevice::length() const
     return lastByte() - firstByte() + 1;
 }
 
-/** Reads a given number of bytes from the Device into the given buffer.
-
-    Note that @p readOffset must be greater or equal than zero.
-
-    @param buffer the buffer to store the read bytes in
-    @param readOffset the offset to begin reading
-    @param size the number of bytes to read
-
-    @return true if successful
-*/
-bool CopySourceDevice::readData(QByteArray& buffer, qint64 readOffset, qint64 size)
-{
-    Q_ASSERT(readOffset >= 0);
-    return m_BackendDevice->readData(buffer, readOffset, size);
-}
-
 /** Checks if this CopySourceDevice overlaps with the given CopyTarget
     @param target the CopyTarget to check overlapping with
     @return true if overlaps
diff --git a/src/core/copysourcedevice.h b/src/core/copysourcedevice.h
index 04f1734..bfdbd45 100644
--- a/src/core/copysourcedevice.h
+++ b/src/core/copysourcedevice.h
@@ -45,7 +45,6 @@ public:
 
 public:
     bool open() override;
-    bool readData(QByteArray& buffer, qint64 readOffset, qint64 size) override;
     qint64 length() const override;
     bool overlaps(const CopyTarget& target) const override;
 
diff --git a/src/core/copysourcefile.cpp b/src/core/copysourcefile.cpp
index 936aec0..40c3a15 100644
--- a/src/core/copysourcefile.cpp
+++ b/src/core/copysourcefile.cpp
@@ -45,18 +45,3 @@ qint64 CopySourceFile::length() const
 {
     return QFileInfo(file()).size();
 }
-
-/** Reads the given number of bytes from the file into the given buffer.
-    @param buffer buffer to store the bytes read in
-    @param readOffset offset where to begin reading
-    @param size the number of bytes to read
-    @return true on success
-*/
-bool CopySourceFile::readData(QByteArray& buffer, qint64 readOffset, qint64 size)
-{
-    if (!file().seek(readOffset))
-        return false;
-
-    buffer = file().read(size);
-    return !buffer.isEmpty();
-}
diff --git a/src/core/copysourcefile.h b/src/core/copysourcefile.h
index 0ff8ff7..3a5cebd 100644
--- a/src/core/copysourcefile.h
+++ b/src/core/copysourcefile.h
@@ -40,7 +40,6 @@ public:
 
 public:
     bool open() override;
-    bool readData(QByteArray& buffer, qint64 readOffset, qint64 size) override;
     qint64 length() const override;
 
     bool overlaps(const CopyTarget&) const override {
diff --git a/src/core/copysourceshred.cpp b/src/core/copysourceshred.cpp
index b8d708e..91ab354 100644
--- a/src/core/copysourceshred.cpp
+++ b/src/core/copysourceshred.cpp
@@ -43,17 +43,3 @@ qint64 CopySourceShred::length() const
 {
     return size();
 }
-
-/** Reads the given number of bytes from the source into the given buffer.
-    @param buffer buffer to store the data read in
-    @param readOffset offset where to begin reading (unused)
-    @param size the number of bytes to read
-    @return true on success
-*/
-bool CopySourceShred::readData(QByteArray& buffer, qint64 readOffset, qint64 size)
-{
-    Q_UNUSED(readOffset);
-
-    buffer = sourceFile().read(size);
-    return !buffer.isEmpty();
-}
diff --git a/src/core/copysourceshred.h b/src/core/copysourceshred.h
index e293531..a181100 100644
--- a/src/core/copysourceshred.h
+++ b/src/core/copysourceshred.h
@@ -39,7 +39,6 @@ public:
 
 public:
     bool open() override;
-    bool readData(QByteArray& buffer, qint64 readOffset, qint64 size) override;
     qint64 length() const override;
 
     bool overlaps(const CopyTarget&) const override {
diff --git a/src/core/copytarget.h b/src/core/copytarget.h
index 97385a1..92324f6 100644
--- a/src/core/copytarget.h
+++ b/src/core/copytarget.h
@@ -41,7 +41,6 @@ protected:
 
 public:
     virtual bool open() = 0;
-    virtual bool writeData(QByteArray& buffer, qint64 writeOffset) = 0;
     virtual qint64 firstByte() const = 0;
     virtual qint64 lastByte() const = 0;
     virtual QString path() const = 0;
diff --git a/src/core/copytargetdevice.cpp b/src/core/copytargetdevice.cpp
index 92e67f2..2ad9a02 100644
--- a/src/core/copytargetdevice.cpp
+++ b/src/core/copytargetdevice.cpp
@@ -52,25 +52,6 @@ bool CopyTargetDevice::open()
     return m_BackendDevice != nullptr;
 }
 
-/** Writes the given number of bytes to the Device.
-
-    Note that @p writeOffset must be greater or equal than zero.
-
-    @param buffer the data to write
-    @param writeOffset where to start writing on the Device
-    @return true on success
-*/
-bool CopyTargetDevice::writeData(QByteArray& buffer, qint64 writeOffset)
-{
-    Q_ASSERT(writeOffset >= 0);
-    bool rval = m_BackendDevice->writeData(buffer, writeOffset);
-
-    if (rval)
-        setBytesWritten(bytesWritten() + buffer.size());
-
-    return rval;
-}
-
 QString CopyTargetDevice::path() const
 {
     return m_Device.deviceNode();
diff --git a/src/core/copytargetdevice.h b/src/core/copytargetdevice.h
index 556b75e..f7021d2 100644
--- a/src/core/copytargetdevice.h
+++ b/src/core/copytargetdevice.h
@@ -46,7 +46,6 @@ public:
 
 public:
     bool open() override;
-    bool writeData(QByteArray& buffer, qint64 writeOffset) override;
     qint64 firstByte() const override {
         return m_FirstByte;    /**< @return the first byte to write to */
     }
diff --git a/src/core/copytargetfile.cpp b/src/core/copytargetfile.cpp
index 508f9b2..bd87637 100644
--- a/src/core/copytargetfile.cpp
+++ b/src/core/copytargetfile.cpp
@@ -33,21 +33,3 @@ bool CopyTargetFile::open()
 {
     return file().open(QIODevice::WriteOnly | QIODevice::Truncate);
 }
-
-/** Writes the given number of bytes from the given buffer to the file.
-    @param buffer the data to write
-    @param writeOffset where in the file to start writing
-    @return true on success
-*/
-bool CopyTargetFile::writeData(QByteArray& buffer, qint64 writeOffset)
-{
-    if (!file().seek(writeOffset))
-        return false;
-
-    bool rval = file().write(buffer) == buffer.size();
-
-    if (rval)
-        setBytesWritten(bytesWritten() + buffer.size());
-
-    return rval;
-}
diff --git a/src/core/copytargetfile.h b/src/core/copytargetfile.h
index 17ecff2..258a403 100644
--- a/src/core/copytargetfile.h
+++ b/src/core/copytargetfile.h
@@ -40,7 +40,6 @@ public:
 
 public:
     bool open() override;
-    bool writeData(QByteArray& buffer, qint64 writeOffset) override;
 
     qint64 firstByte() const override {
         return 0;    /**< @return always 0 for a file */
diff --git a/src/plugins/dummy/dummydevice.cpp b/src/plugins/dummy/dummydevice.cpp
index 92c2de7..d2b43e9 100644
--- a/src/plugins/dummy/dummydevice.cpp
+++ b/src/plugins/dummy/dummydevice.cpp
@@ -66,26 +66,3 @@ bool DummyDevice::createPartitionTable(Report& report, const PartitionTable& pta
 
     return true;
 }
-
-bool DummyDevice::readData(QByteArray& buffer, qint64 offset, qint64 size)
-{
-    Q_UNUSED(buffer);
-    Q_UNUSED(offset);
-    Q_UNUSED(size);
-
-    if (!isExclusive())
-        return false;
-
-    return true;
-}
-
-bool DummyDevice::writeData(QByteArray& buffer, qint64 offset)
-{
-    Q_UNUSED(buffer);
-    Q_UNUSED(offset);
-
-    if (!isExclusive())
-        return false;
-
-    return true;
-}
diff --git a/src/plugins/dummy/dummydevice.h b/src/plugins/dummy/dummydevice.h
index 9493365..6895e65 100644
--- a/src/plugins/dummy/dummydevice.h
+++ b/src/plugins/dummy/dummydevice.h
@@ -44,9 +44,6 @@ public:
     CoreBackendPartitionTable* openPartitionTable() override;
 
     bool createPartitionTable(Report& report, const PartitionTable& ptable) override;
-
-    bool readData(QByteArray& buffer, qint64 offset, qint64 size) override;
-    bool writeData(QByteArray& buffer, qint64 offset) override;
 };
 
 #endif
diff --git a/src/plugins/libparted/libparteddevice.cpp b/src/plugins/libparted/libparteddevice.cpp
index 6354b58..d97e41c 100644
--- a/src/plugins/libparted/libparteddevice.cpp
+++ b/src/plugins/libparted/libparteddevice.cpp
@@ -110,23 +110,3 @@ bool LibPartedDevice::createPartitionTable(Report& report, const PartitionTable&
 
     return LibPartedPartitionTable::commit(disk);
 }
-
-bool LibPartedDevice::readData(QByteArray& buffer, qint64 offset, qint64 size)
-{
-     if (!isExclusive())
-         return false;
-
-    void *data = malloc(size);
-    bool rval = ped_device_read(pedDevice(), data, offset / pedDevice()->sector_size, size / pedDevice()->sector_size);
-    buffer = QByteArray(static_cast<char*>(data), size);
-    free(data);
-    return rval;
-}
-
-bool LibPartedDevice::writeData(QByteArray& buffer, qint64 offset)
-{
-    if (!isExclusive())
-        return false;
-
-    return ped_device_write(pedDevice(), static_cast<const void *>(buffer.constData()), offset / pedDevice()->sector_size, buffer.size() / pedDevice()->sector_size);
-}
diff --git a/src/plugins/libparted/libparteddevice.h b/src/plugins/libparted/libparteddevice.h
index c8d98c0..dc8f16a 100644
--- a/src/plugins/libparted/libparteddevice.h
+++ b/src/plugins/libparted/libparteddevice.h
@@ -47,9 +47,6 @@ public:
 
     bool createPartitionTable(Report& report, const PartitionTable& ptable) override;
 
-    bool readData(QByteArray& buffer, qint64 offset, qint64 size) override;
-    bool writeData(QByteArray& buffer, qint64 offset) override;
-
 protected:
     PedDevice* pedDevice() {
         return m_PedDevice;
diff --git a/src/plugins/sfdisk/sfdiskdevice.cpp b/src/plugins/sfdisk/sfdiskdevice.cpp
index c8ce382..7dfc248 100644
--- a/src/plugins/sfdisk/sfdiskdevice.cpp
+++ b/src/plugins/sfdisk/sfdiskdevice.cpp
@@ -79,40 +79,3 @@ bool SfdiskDevice::createPartitionTable(Report& report, const PartitionTable& pt
 
     return false;
 }
-
-bool SfdiskDevice::readData(QByteArray& buffer, qint64 offset, qint64 size)
-{
-    if (!isExclusive())
-        return false;
-
-    ExternalCommand ddCommand(QStringLiteral("dd"), {
-                QStringLiteral("skip=") + QString::number(offset),
-                QStringLiteral("bs=") + QString::number(size),
-                QStringLiteral("count=1"),
-                QStringLiteral("iflag=skip_bytes"),
-                QStringLiteral("if=") + m_device->deviceNode() }, QProcess::SeparateChannels);
-    if (ddCommand.run(-1) && ddCommand.exitCode() == 0) {
-        buffer = ddCommand.rawOutput();
-        return true;
-    }
-
-    return false;
-}
-
-bool SfdiskDevice::writeData(QByteArray& buffer, qint64 offset)
-{
-    if (!isExclusive())
-        return false;
-
-    ExternalCommand ddCommand(QStringLiteral("dd"), {
-                QStringLiteral("of=") + m_device->deviceNode(),
-                QStringLiteral("seek=") + QString::number(offset),
-                QStringLiteral("bs=1M"),
-                QStringLiteral("oflag=seek_bytes"),
-                QStringLiteral("conv=fsync") }, QProcess::SeparateChannels);
-    if ( ddCommand.write(buffer) && ddCommand.start(-1) && ddCommand.waitFor() && ddCommand.exitCode() == 0 ) {
-        return true;
-    }
-
-    return false;
-}
diff --git a/src/plugins/sfdisk/sfdiskdevice.h b/src/plugins/sfdisk/sfdiskdevice.h
index aeab327..096dd74 100644
--- a/src/plugins/sfdisk/sfdiskdevice.h
+++ b/src/plugins/sfdisk/sfdiskdevice.h
@@ -46,9 +46,6 @@ public:
 
     bool createPartitionTable(Report& report, const PartitionTable& ptable) override;
 
-    bool readData(QByteArray& buffer, qint64 offset, qint64 size) override;
-    bool writeData(QByteArray& buffer, qint64 offset) override;
-
 private:
     const Device *m_device;
 };
diff --git a/src/util/externalcommandhelper.cpp b/src/util/externalcommandhelper.cpp
index 3d77b81..3694e5b 100644
--- a/src/util/externalcommandhelper.cpp
+++ b/src/util/externalcommandhelper.cpp
@@ -25,7 +25,13 @@
 
 #include <KLocalizedString>
 
-
+/** Reads the given number of bytes from the sourceDevice into the given buffer.
+    @param sourceDevice device or file to read from
+    @param buffer buffer to store the bytes read in
+    @param offset offset where to begin reading
+    @param size the number of bytes to read
+    @return true on success
+*/
 bool ExternalCommandHelper::readData(QString& sourceDevice, QByteArray& buffer, qint64 offset, qint64 size)
 {
     QFile device(sourceDevice);
@@ -50,6 +56,12 @@ bool ExternalCommandHelper::readData(QString& sourceDevice, QByteArray& buffer,
     return true;
 }
 
+/** Writes the data from buffer to a given device or file.
+    @param targetDevice device or file to write to
+    @param buffer the data that we write
+    @param offset offset where to begin writing
+    @return true on success
+*/
 bool ExternalCommandHelper::writeData(QString &targetDevice, QByteArray& buffer, qint64 offset)
 {
     QFile device(targetDevice);