sys-dm-linux-proc-meminfo-transact-sql.md

title	sys.dm_linux_proc_meminfo (Transact-SQL) | Microsoft Docs
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sys.dm_linux_proc_meminfo (Transact-SQL)

[!INCLUDEtsql-appliesto-ssLinx-xxxx-xxxx-xxx]

Returns information about memory page allocation when [!INCLUDEssNoVersion_md] is running on Linux.
This dmv is based off of the linux /proc/meminfo file. It provides information about your system's memory. If a field is missing from the file, it will be set to NULL in the DMV.

Note

Implementation of this DMV has been delayed. Expect it, or something similar in a future CTP.

Column name	Data type	Description
memtotal_kb	bigint	Total usable ram (physical ram minus reserved bits and the kernel binary code) in kilobytes.
memfree_kb	bigint	The amount of physical RAM, in kilobytes, left unused by the system.
memavailable_kb	bigint	An estimate of how much memory is available for starting new applications, without swapping.
buffers_kb	bigint	The amount of physical RAM, in kilobytes, used for file buffers.
cached_kb	bigint	Memory in the pagecache (diskcache) minus the SwapCache, in kilobytes.
swapcached_kb	bigint	Cached memory that once was swapped out. When swapped back in it remains in the swapfile. If memory is needed it doesn't need to be swapped out again because it is already in the swapfile. This saves I/O.
active_kb	bigint	The total amount of buffer or page cache memory, in kilobytes, that is in active use. This is memory that has been recently used and is usually not reclaimed for other purposes.
inactive_kb	bigint	The total amount of buffer or page cache memory, in kilobytes, that are free and available. This is memory that has not been recently used and can be reclaimed for other purposes.
active(anon)_kb	bigint	The amount of anonymous and tmpfs/shmem memory, in kilobytes, that is in active use, or was in active use since the last time the system moved something to swap.
inactive(anon)_kb	bigint	The amount of anonymous and tmpfs/shmem memory, in kilobytes, that is a candidate for eviction.
active(file)_kb	bigint	The amount of file cache memory, in kilobytes, that is in active use, or was in active use since the last time the system reclaimed memory.
inactive(file)_kb	bigint	The amount of file cache memory, in kilobytes, that is newly loaded from the disk, or is a candidate for reclaiming.
unevictable_kb	bigint	The amount of memory, in kilobytes, discovered by the pageout code, that is not evictable because it is locked into memory by user programs.
mlocked_kb	bigint	The total amount of memory, in kilobytes, that is not evictable because it is locked into memory by user programs.
swaptotal_kb	bigint	The total amount of swap available, in kilobytes.
swapfree_kb	bigint	The total amount of swap free, in kilobytes.
dirty_kb	bigint	The total amount of memory, in kilobytes, waiting to be written back to the disk.
writeback_kb	bigint	The total amount of memory, in kilobytes, actively being written back to the disk.
anonpages_kb	bigint	The total amount of memory, in kilobytes, used by pages that are not backed by files and are mapped into userspace page tables.
mapped_kb	bigint	The total amount of memory, in kilobytes, which have been used to map devices, files, or libraries using the mmap command.
shmem_kb	bigint	The total amount of memory, in kilobytes, used by shared memory (shmem) and tmpfs.
slab_kb	bigint	The total amount of memory, in kilobytes, used by the kernel to cache data structures for its own use.
sreclaimable_kb	bigint	The part of Slab that can be reclaimed, such as caches.
sunreclaim_kb	bigint	The part of Slab that cannot be reclaimed even when lacking memory.
kernelstack_kb	bigint	The amount of memory, in kilobytes, used by the kernel stack allocations done for each task in the system.
pagetables_kb	bigint	The total amount of memory, in kibibytes, dedicated to the lowest page table level.
nfs_unstable_kb	bigint	The amount, in kibibytes, of NFS pages sent to the server but not yet committed to the stable storage.
bounce_kb	bigint	The amount of memory, in kilobytes, used for the block device "bounce buffers".
writebacktmp_kb	bigint	The amount of memory, in kilobytes, used by FUSE for temporary writeback buffers.
commitlimit_kb	bigint	The total amount of memory currently available to be allocated on the system based on the overcommit ratio (vm.overcommit_ratio). This limit is only adhered to if strict overcommit accounting is enabled (mode 2 in vm.overcommit_memory).
committed_as_kb	bigint	The total amount of memory, in kilobytes, estimated to complete the workload. This value represents the worst case scenario value, and also includes swap memory.
vmalloctotal_kb	bigint	The total amount of memory, in kilobytes, of total allocated virtual address space.
vmallocused_kb	bigint	The total amount of memory, in kilobytes, of used virtual address sp.
vmallocchunk_kb	bigint	The largest contiguous block of memory, in kilobytes, of available virtual address space.
hardwarecorrupted_kb	bigint	The amount of memory, in kibibytes, with physical memory corruption problems, identified by the hardware and set aside by the kernel so it does not get used.
anonhugepages_kb	bigint	The total amount of memory, in kibibytes, used by huge pages that are not backed by files and are mapped into userspace page tables.
cmatotal_kb	bigint	Total CMA (Contiguous Memory Allocator) pages. (CONFIG_CMA is required.)
cmafree_kb	bigint	Free CMA (Contiguous Memory Allocator) pages. (CONFIG_CMA is required.)
hugepages_total	bigint	The total number of hugepages for the system. The number is derived by dividing Hugepagesize by the megabytes set aside for hugepages specified in /proc/sys/vm/hugetlb_pool. This statistic only appears on the x86, Itanium, and AMD64 architectures.
hugepages_free	bigint	The total number of hugepages available for the system. This statistic only appears on the x86, Itanium, and AMD64 architectures.
hugepages_rsvd	bigint	The number of unused hugepages reserved for hugetlbfs.
hugepages_surp	bigint	The number of surplus hugepages.
hugepagesize_kb	bigint	The size for each hugepages unit in kilobytes. By default, the value is 4096 KB on uniprocessor kernels for 32 bit architectures. For SMP, hugemem kernels, and AMD64, the default is 2048 KB. For Itanium architectures, the default is 262144 KB. This statistic only appears on the x86, Itanium, and AMD64 architectures.
directmap4k_kb	bigint	The amount of memory, in kilobytes, mapped into kernel address space with 4 kB page mappings.
directmap2m_kb	bigint	The amount of memory, in kilobytes, mapped into kernel address space with 2 MB page mappings.
overflow	nvarchar(4000)	Any unrecognized data we encountered in /proc/meminfo. These are in JSON key-value pair format.

Note

Your Linux documentation may be able to provide additional information. Some of the information for this topic was extracted from Red Hat®, Inc documentation at E.2.18/proc/meminfo.

Remarks

Returns an empty row set when called on a Windows computer.

Permissions

Requires VIEW SERVER STATE permission.

Examples

The following query returns high-level system memory information.

SELECT memtotal_kb, memfree_kb, memavailable_kb 
FROM sys.dm_linux_proc_meminfo;

See Also

Linux Process Dynamic Management Views (Transact-SQL)