#Memory monitor ubuntu free#

This 1GB is memory which has been “committed” to by the VM and can be used at any time by the allocating application. A process which allocates 1GB of memory (using malloc(3) or similar), but touches only 300MB of that memory will show up as using only 300MB of memory even if it has the address space allocated for the entire 1GB. The committed memory is a sum of all of the memory which has been allocated by processes, even if it has not been “used” by them as of yet. The amount of memory presently allocated on the system. The limit is calculated according to the formula described under /proc/sys/vm/overcommit_memory.

This limit is adhered to only if strict overcommit accounting is enabled (mode 2 in /proc/sys/vm/overcommit_memory). This is the total amount of memory currently available to be allocated on the system, expressed in kilobytes. Memory used by FUSE for temporary writeback buffers. Memory used for block device “bounce buffers”. NFS pages sent to the server, but not yet committed to stable storage. Part of Slab, that cannot be reclaimed on memory pressure.Īmount of memory allocated to kernel stacks.Īmount of memory dedicated to the lowest level of page tables. Part of Slab, that might be reclaimed, such as caches. Includes SReclaimable (below), and other direct allocations with a shrinker. Kernel allocations that the kernel will attempt to reclaim under memory pressure. Non-file backed pages mapped into user-space page tables.įiles which have been mapped into memory (with mmap(2)), such as libraries.Īmount of memory consumed in tmpfs(5) filesystems. Memory which is actively being written back to the disk. Memory which is waiting to get written back to the disk. The kernel must use tricks to access this memory, making it slower to access than lowmem.Īmount of swap space that is currently unused. Highmem areas are for use by user-space programs, or for the page cache. Highmem is all memory above ~860MB of physical memory. It is more eligible to be reclaimed for other purposes. Memory which has been less recently used. Memory that has been used more recently and usually not reclaimed unless absolutely necessary. Memory that once was swapped out, is swapped back in but still also is in the swap file. In-memory cache for files read from the disk (the page cache). Relatively temporary storage for raw disk blocks that shouldn’t get tremendously large (20MB or so). (since Linux 3.14) An estimate of how much memory is available for starting new applications, without swapping. Total usable RAM (i.e., physical RAM minus a few reserved bits and the kernel binary code). Understanding memory utilization parameters Fields description table Parameter Use the cat command/ less command or grep command/ egrep command as follows on your Linux box:Įach line of the /proc/meminfo file consists of a parameter name, followed by a colon, the parameter value, and an option unit of measurement. The /proc/meminfo file reports statistics about memory usage on Linux. It would be best if you kept an eye on buffers and caches used by the kernel too.

#Memory monitor ubuntu free#

A developer or seasoned sysadmin must know the total amount of free and used physical, including swap memory in the server. Memory plays a critical role in a Linux system. Your Linux system must run at an optimal level. Commands to check memory utilization in Linux