diff --git a/src/Disks/IVolume.cpp b/src/Disks/IVolume.cpp
index 48e6fbac936..e67ac9963e9 100644
--- a/src/Disks/IVolume.cpp
+++ b/src/Disks/IVolume.cpp
@@ -81,9 +81,9 @@ Disks MultiDiskReservation::getDisks() const
 {
     Disks res;
     res.reserve(reservations.size());
-    for (const auto &r: reservations)
+    for (const auto & reservation : reservations)
     {
-        res.push_back(r->getDisk());
+        res.push_back(reservation->getDisk());
     }
     return res;
 }
diff --git a/src/Disks/IVolume.h b/src/Disks/IVolume.h
index 88f3e5226b2..4033ba1e543 100644
--- a/src/Disks/IVolume.h
+++ b/src/Disks/IVolume.h
@@ -67,7 +67,7 @@ protected:
 class MultiDiskReservation : public IReservation
 {
 public:
-    MultiDiskReservation(Reservations &reservations, UInt64 size);
+    MultiDiskReservation(Reservations & reservations, UInt64 size);
 
     UInt64 getSize() const override { return size; }
 
diff --git a/src/Disks/VolumeJBOD.cpp b/src/Disks/VolumeJBOD.cpp
index 7312f3d2365..6c0d9ec0a89 100644
--- a/src/Disks/VolumeJBOD.cpp
+++ b/src/Disks/VolumeJBOD.cpp
@@ -64,7 +64,8 @@ DiskPtr VolumeJBOD::getNextDisk()
 
 ReservationPtr VolumeJBOD::reserve(UInt64 bytes)
 {
-    /// This volume can not store files which size greater than max_data_part_size
+    /// This volume can not store data which size is greater than `max_data_part_size`
+    /// to ensure that parts of size greater than that go to another volume(s).
 
     if (max_data_part_size != 0 && bytes > max_data_part_size)
         return {};
diff --git a/src/Disks/VolumeRAID1.cpp b/src/Disks/VolumeRAID1.cpp
index 764bea8e68a..6d30c6bb0bd 100644
--- a/src/Disks/VolumeRAID1.cpp
+++ b/src/Disks/VolumeRAID1.cpp
@@ -8,7 +8,8 @@ namespace DB
 
 ReservationPtr VolumeRAID1::reserve(UInt64 bytes)
 {
-    /// This volume can not store files which size greater than max_data_part_size
+    /// This volume can not store data which size is greater than `max_data_part_size`
+    /// to ensure that parts of size greater than that go to another volume(s).
 
     if (max_data_part_size != 0 && bytes > max_data_part_size)
         return {};
diff --git a/src/Disks/VolumeRAID1.h b/src/Disks/VolumeRAID1.h
index 4452928445a..92d2b0267bf 100644
--- a/src/Disks/VolumeRAID1.h
+++ b/src/Disks/VolumeRAID1.h
@@ -8,7 +8,6 @@ namespace DB
 
 class VolumeRAID1 : public VolumeJBOD
 {
-    friend VolumePtr createVolumeFromReservation(const ReservationPtr & reservation, VolumePtr other_volume);
 public:
     VolumeRAID1(String name_, Disks disks_, UInt64 max_data_part_size_)
         : VolumeJBOD(name_, disks_, max_data_part_size_)