Both of those server configuration options do not require a restart of the database engine. Running RECONFIGURE will be sufficient in this case.
exec sp_configure 'show advanced options', 1
go
reconfigure
go
exec sp_configure 'max server memory', 12288
go
exec sp_configure 'max degree of parallelism', 4
go
reconfigure
go
-- the new configuration has taken effect
Please see BOL for reference.
Looking at your RAM availablity for this particular server and you are running several databases ranging from 30GB to 5 GB, you definitely need more RAM on this server.
You have not mentioned that this is a stand alone instance or this server is having more than one instance of sql server running.
Your MAX Memory settings seems OK for a server having 8GB RAM. See these suggested best practice settings from Glenn Berry.
I would highly recommend you to do a baseline of your environment using below PERFMON counters to get a good value of your memory configuration :
- SQL Server:Buffer Manager\Page Life Expectancy
- SQL Server:Buffer Manager\Page reads/sec
- Physical Disk\Disk Reads/sec
- Memory\Available Mbytes
- SQL Server: Memory Manager - Total Server Memory
- SQL Server: Memory Manager - Target Server Memory
Total Server Memory: Amount of memory currently allocated to Buffer Pool and not the total amount of memory to SQL Server
Target Server memory: Ideal Size of the buffer pool corresponding to max memory for the instance.
Note: If Total Server Memory > Target Server memory, then it suggests memory pressure.
Below script will help you find LOW or HIGH Memory notifications from sys.dm_os_ring_buffers - system health session :
SELECT CONVERT (varchar(30), GETDATE(), 121) as [RunTime],
dateadd (ms, (rbf.[timestamp] - tme.ms_ticks), GETDATE()) as [Notification_Time],
cast(record as xml).value('(//Record/ResourceMonitor/Notification)[1]', 'varchar(30)') AS [Notification_type],
cast(record as xml).value('(//Record/MemoryRecord/MemoryUtilization)[1]', 'bigint') AS [MemoryUtilization %],
cast(record as xml).value('(//Record/MemoryNode/@id)[1]', 'bigint') AS [Node Id],
cast(record as xml).value('(//Record/ResourceMonitor/IndicatorsProcess)[1]', 'int') AS [Process_Indicator],
cast(record as xml).value('(//Record/ResourceMonitor/IndicatorsSystem)[1]', 'int') AS [System_Indicator],
cast(record as xml).value('(//Record/MemoryNode/ReservedMemory)[1]', 'bigint') AS [SQL_ReservedMemory_KB],
cast(record as xml).value('(//Record/MemoryNode/CommittedMemory)[1]', 'bigint') AS [SQL_CommittedMemory_KB],
cast(record as xml).value('(//Record/MemoryNode/AWEMemory)[1]', 'bigint') AS [SQL_AWEMemory],
cast(record as xml).value('(//Record/MemoryNode/SinglePagesMemory)[1]', 'bigint') AS [SinglePagesMemory],
cast(record as xml).value('(//Record/MemoryNode/MultiplePagesMemory)[1]', 'bigint') AS [MultiplePagesMemory],
cast(record as xml).value('(//Record/MemoryRecord/TotalPhysicalMemory)[1]', 'bigint') AS [TotalPhysicalMemory_KB],
cast(record as xml).value('(//Record/MemoryRecord/AvailablePhysicalMemory)[1]', 'bigint') AS [AvailablePhysicalMemory_KB],
cast(record as xml).value('(//Record/MemoryRecord/TotalPageFile)[1]', 'bigint') AS [TotalPageFile_KB],
cast(record as xml).value('(//Record/MemoryRecord/AvailablePageFile)[1]', 'bigint') AS [AvailablePageFile_KB],
cast(record as xml).value('(//Record/MemoryRecord/TotalVirtualAddressSpace)[1]', 'bigint') AS [TotalVirtualAddressSpace_KB],
cast(record as xml).value('(//Record/MemoryRecord/AvailableVirtualAddressSpace)[1]', 'bigint') AS [AvailableVirtualAddressSpace_KB],
cast(record as xml).value('(//Record/@id)[1]', 'bigint') AS [Record Id],
cast(record as xml).value('(//Record/@type)[1]', 'varchar(30)') AS [Type],
cast(record as xml).value('(//Record/@time)[1]', 'bigint') AS [Record Time],
tme.ms_ticks as [Current Time]
FROM sys.dm_os_ring_buffers rbf
cross join sys.dm_os_sys_info tme
where rbf.ring_buffer_type = 'RING_BUFFER_RESOURCE_MONITOR'
--and cast(record as xml).value('(//Record/ResourceMonitor/Notification)[1]', 'varchar(30)') = 'RESOURCE_MEMPHYSICAL_LOW'
ORDER BY rbf.timestamp ASC
Some good references :
Best Answer
The memory counters in Task Manager or Resource Monitor are not a good way to determine SQL Server's memory usage. If SQL Server is using locked pages, these do not show in the working set or private bytes.
There are many ways to determine if SQL Server is using locked pages. You can look for a message like the following in the error log:
Using locked pages in the memory managerOr, check the
sys.dm_os_process_memoryDMVlocked_page_allocations_kbcolumn. For example, on a local test instance using locked pages I see this:Whereas Resource Monitor shows:
Note this is different from the
sys.dm_os_sys_memoryDMV you mention in the question comments.There is all sorts of other useful memory usage information in the DMVs, including high-or-low virtual or physical memory indications. These are all described in Books Online.
It seems probable that someone has granted the
SeLockMemoryPrivilegeto the SQL Server start-up account recently, or the account has been changed toLocalSystem, which has this privilege by default.Generally speaking, locking pages in memory is a good thing.