diff --git a/src/common/isc_s_proto.h b/src/common/isc_s_proto.h
index f5889159a20..72cb066de3a 100644
--- a/src/common/isc_s_proto.h
+++ b/src/common/isc_s_proto.h
@@ -279,6 +279,9 @@ class SharedMemoryBase
 	int eventWait(event_t* event, const SLONG value, const SLONG micro_seconds);
 	int eventPost(event_t* event);
 
+	// Used as memory allocation unit and mapping alignment
+	static ULONG getSystemPageSize(Firebird::CheckStatusWrapper* status);
+
 public:
 #ifdef UNIX
 	Firebird::AutoPtr<FileLock> mainLock;
@@ -296,6 +299,7 @@ class SharedMemoryBase
 #endif
 
 	ULONG	sh_mem_length_mapped;
+	ULONG	sh_mem_increment;				// Suggested growth increment
 #ifdef WIN_NT
 	HANDLE	sh_mem_handle;					// file handle
 	HANDLE	sh_mem_object;					// file mapping
diff --git a/src/common/isc_sync.cpp b/src/common/isc_sync.cpp
index 58aad818fed..9998406e93f 100644
--- a/src/common/isc_sync.cpp
+++ b/src/common/isc_sync.cpp
@@ -1250,12 +1250,38 @@ void SharedMemoryBase::internalUnmap()
 	}
 }
 
+
+ULONG SharedMemoryBase::getSystemPageSize(CheckStatusWrapper* statusVector)
+{
+	// Get system page size as this is the unit of mapping.
+
+#ifdef SOLARIS
+	const long ps = sysconf(_SC_PAGESIZE);
+	if (ps == -1)
+	{
+		error(statusVector, "sysconf", errno);
+		return 0;
+	}
+#else
+	const int ps = getpagesize();
+	if (ps == -1)
+	{
+		error(statusVector, "getpagesize", errno);
+		return 0;
+	}
+#endif
+	return ps;
+}
+
+
 SharedMemoryBase::SharedMemoryBase(const TEXT* filename, ULONG length, IpcObject* callback, bool skipLock)
 	:
 #ifdef HAVE_SHARED_MUTEX_SECTION
 	sh_mem_mutex(0),
 #endif
-	sh_mem_length_mapped(0), sh_mem_header(NULL),
+	sh_mem_length_mapped(0),
+	sh_mem_increment(0),
+	sh_mem_header(NULL),
 	sh_mem_callback(callback)
 {
 /**************************************
@@ -1286,6 +1312,14 @@ SharedMemoryBase::SharedMemoryBase(const TEXT* filename, ULONG length, IpcObject
 	TEXT init_filename[MAXPATHLEN];
 	iscPrefixLock(init_filename, INIT_FILE, true);
 
+	if (length)
+	{
+		sh_mem_increment = length = FB_ALIGN(length, getSystemPageSize(&statusVector));
+
+		if (statusVector.hasData())
+			status_exception::raise(&statusVector);
+	}
+
 	const bool trunc_flag = (length != 0);
 
 	// open the init lock file
@@ -1569,8 +1603,17 @@ void SharedMemoryBase::internalUnmap()
 		unlinkFile();
 }
 
+
+ULONG SharedMemoryBase::getSystemPageSize(CheckStatusWrapper* /*statusVector*/)
+{
+	SYSTEM_INFO sys_info;
+	GetSystemInfo(&sys_info);
+	return sys_info.dwAllocationGranularity;
+}
+
+
 SharedMemoryBase::SharedMemoryBase(const TEXT* filename, ULONG length, IpcObject* cb, bool /*skipLock*/)
-  :	sh_mem_mutex(0), sh_mem_length_mapped(0),
+  :	sh_mem_mutex(0), sh_mem_length_mapped(0), sh_mem_increment(0),
 	sh_mem_handle(INVALID_HANDLE_VALUE), sh_mem_object(0), sh_mem_interest(0), sh_mem_hdr_object(0),
 	sh_mem_hdr_address(0), sh_mem_header(NULL), sh_mem_callback(cb), sh_mem_unlink(false)
 {
@@ -1598,6 +1641,17 @@ SharedMemoryBase::SharedMemoryBase(const TEXT* filename, ULONG length, IpcObject
 	bool init_flag = false;
 	DWORD err = 0;
 
+	if (length)
+	{
+		LocalStatus ls;
+		CheckStatusWrapper statusVector(&ls);
+
+		sh_mem_increment = length = FB_ALIGN(length, getSystemPageSize(&statusVector));
+
+		if (statusVector.hasData())
+			status_exception::raise(&statusVector);
+	}
+
 	// retry to attach to mmapped file if the process initializing dies during initialization.
 
   retry:
@@ -1925,24 +1979,9 @@ UCHAR* SharedMemoryBase::mapObject(CheckStatusWrapper* statusVector, ULONG objec
  *
  **************************************/
 
-	// Get system page size as this is the unit of mapping.
-
-#ifdef SOLARIS
-	const long ps = sysconf(_SC_PAGESIZE);
-	if (ps == -1)
-	{
-		error(statusVector, "sysconf", errno);
+	const ULONG page_size = getSystemPageSize(statusVector);
+	if (!page_size)
 		return NULL;
-	}
-#else
-	const int ps = getpagesize();
-	if (ps == -1)
-	{
-		error(statusVector, "getpagesize", errno);
-		return NULL;
-	}
-#endif
-	const ULONG page_size = (ULONG) ps;
 
 	// Compute the start and end page-aligned offsets which contain the object being mapped.
 
@@ -1980,24 +2019,9 @@ void SharedMemoryBase::unmapObject(CheckStatusWrapper* statusVector, UCHAR** obj
  *	Zero the object pointer after a successful unmap.
  *
  **************************************/
-	// Get system page size as this is the unit of mapping.
-
-#ifdef SOLARIS
-	const long ps = sysconf(_SC_PAGESIZE);
-	if (ps == -1)
-	{
-		error(statusVector, "sysconf", errno);
-		return;
-	}
-#else
-	const int ps = getpagesize();
-	if (ps == -1)
-	{
-		error(statusVector, "getpagesize", errno);
+	const size_t page_size = getSystemPageSize(statusVector);
+	if (!page_size)
 		return;
-	}
-#endif
-	const size_t page_size = (ULONG) ps;
 
 	// Compute the start and end page-aligned addresses which contain the mapped object.
 
@@ -2035,9 +2059,7 @@ UCHAR* SharedMemoryBase::mapObject(CheckStatusWrapper* statusVector,
  *
  **************************************/
 
-	SYSTEM_INFO sys_info;
-	GetSystemInfo(&sys_info);
-	const ULONG page_size = sys_info.dwAllocationGranularity;
+	const ULONG page_size = getSystemPageSize(statusVector);
 
 	// Compute the start and end page-aligned offsets which
 	// contain the object being mapped.
@@ -2047,6 +2069,8 @@ UCHAR* SharedMemoryBase::mapObject(CheckStatusWrapper* statusVector,
 	const ULONG length = end - start;
 	const HANDLE handle = sh_mem_object;
 
+	fb_assert(end <= sh_mem_length_mapped);
+
 	UCHAR* address = (UCHAR*) MapViewOfFile(handle, FILE_MAP_WRITE, 0, start, length);
 
 	if (address == NULL)
@@ -2075,9 +2099,7 @@ void SharedMemoryBase::unmapObject(CheckStatusWrapper* statusVector,
  *	Zero the object pointer after a successful unmap.
  *
  **************************************/
-	SYSTEM_INFO sys_info;
-	GetSystemInfo(&sys_info);
-	const size_t page_size = sys_info.dwAllocationGranularity;
+	const size_t page_size = getSystemPageSize(statusVector);
 
 	// Compute the start and end page-aligned offsets which
 	// contain the object being mapped.
@@ -2497,6 +2519,8 @@ bool SharedMemoryBase::remapFile(CheckStatusWrapper* statusVector, ULONG new_len
 
 	if (flag)
 	{
+		new_length = FB_ALIGN(new_length, getSystemPageSize(statusVector));
+
 		FB_UNUSED(os_utils::ftruncate(mainLock->getFd(), new_length));
 
 		if (new_length > sh_mem_length_mapped)
@@ -2553,6 +2577,8 @@ bool SharedMemoryBase::remapFile(CheckStatusWrapper* statusVector,
 
 	if (flag)
 	{
+		new_length = FB_ALIGN(new_length, getSystemPageSize(statusVector));
+
 		LARGE_INTEGER offset;
 		offset.QuadPart = new_length;
 
diff --git a/src/jrd/event.cpp b/src/jrd/event.cpp
index ffbb4e1bb59..59b8139f9ad 100644
--- a/src/jrd/event.cpp
+++ b/src/jrd/event.cpp
@@ -534,8 +534,10 @@ frb* EventManager::alloc_global(UCHAR type, ULONG length, bool recurse)
 #ifdef HAVE_OBJECT_MAP
 	if (!best && !recurse)
 	{
+		fb_assert(length <= m_sharedMemory->sh_mem_increment);
+
 		const ULONG old_length = m_sharedMemory->sh_mem_length_mapped;
-		const ULONG ev_length = old_length + m_config->getEventMemSize();
+		const ULONG ev_length = old_length + m_sharedMemory->sh_mem_increment;
 
 		LocalStatus ls;
 		CheckStatusWrapper localStatus(&ls);
diff --git a/src/lock/lock.cpp b/src/lock/lock.cpp
index 3739f3ce6af..42cc614f17b 100644
--- a/src/lock/lock.cpp
+++ b/src/lock/lock.cpp
@@ -177,11 +177,26 @@ LockManager::LockManager(const string& id, const Config* conf)
 	  m_config(conf),
 	  m_acquireSpins(m_config->getLockAcquireSpins()),
 	  m_memorySize(m_config->getLockMemSize()),
+	  m_hashSlots(m_config->getLockHashSlots()),
 	  m_useBlockingThread(m_config->getServerMode() != MODE_SUPER)
 #ifdef USE_SHMEM_EXT
 	  , m_extents(getPool())
 #endif
 {
+	if (m_hashSlots < HASH_MIN_SLOTS)
+		m_hashSlots = HASH_MIN_SLOTS;
+	if (m_hashSlots > HASH_MAX_SLOTS)
+		m_hashSlots = HASH_MAX_SLOTS;
+
+	// memory size required to fit all hash slots, history blocks and header blocks
+	const auto minMemory = sizeof(lhb) +
+		FB_ALIGN(sizeof(shb), FB_ALIGNMENT) +
+		sizeof(lhb::lhb_hash[0]) * m_hashSlots +
+		FB_ALIGN(sizeof(his), FB_ALIGNMENT) * HISTORY_BLOCKS * 2;
+
+	if (m_memorySize < minMemory)
+		m_memorySize = minMemory;
+
 	LocalStatus ls;
 	CheckStatusWrapper localStatus(&ls);
 	if (!init_shared_file(&localStatus))
@@ -304,6 +319,9 @@ bool LockManager::init_shared_file(CheckStatusWrapper* statusVector)
 
 		const auto header = tmp->getHeader();
 		checkHeader(header);
+
+		// Get properly aligned value
+		m_memorySize = m_sharedMemory->sh_mem_increment;
 	}
 	catch (const Exception& ex)
 	{
@@ -2330,13 +2348,7 @@ bool LockManager::initialize(SharedMemoryBase* sm, bool initializeMemory)
 	SRQ_INIT(hdr->lhb_free_locks);
 	SRQ_INIT(hdr->lhb_free_requests);
 
-	int hash_slots = m_config->getLockHashSlots();
-	if (hash_slots < HASH_MIN_SLOTS)
-		hash_slots = HASH_MIN_SLOTS;
-	if (hash_slots > HASH_MAX_SLOTS)
-		hash_slots = HASH_MAX_SLOTS;
-
-	hdr->lhb_hash_slots = (USHORT) hash_slots;
+	hdr->lhb_hash_slots = m_hashSlots;
 	hdr->lhb_scan_interval = m_config->getDeadlockTimeout();
 	hdr->lhb_acquire_spins = m_acquireSpins;
 
diff --git a/src/lock/lock_proto.h b/src/lock/lock_proto.h
index b0b14511938..444c6c51e8b 100644
--- a/src/lock/lock_proto.h
+++ b/src/lock/lock_proto.h
@@ -507,7 +507,8 @@ class LockManager final : public Firebird::GlobalStorage, public Firebird::IpcOb
 
 	// configurations parameters - cached values
 	const ULONG m_acquireSpins;
-	const ULONG m_memorySize;
+	ULONG m_memorySize;
+	USHORT m_hashSlots;
 	const bool m_useBlockingThread;
 
 #ifdef USE_SHMEM_EXT