show memory
CF-708
Cisco IOS Configuration Fundamentals Command Reference
July 2008
The output of the show memory free command contains the same types of information as the show
memory output, except that only free memory is displayed, and the information is ordered by free list.
The first section of the display includes summary statistics about the activities of the system memory
allocator. Table 9 7 describes the significant fields shown in the first section of the display.
The second section of the display is a block-by-block listing of memory use. Table 9 8 describes the
significant fields shown in the second section of the display.
The show memory io command displays the free I/O memory blocks. On the Cisco 4000 router, this
command quickly shows how much unused I/O memory is available.
The following is sample output from the show memory io command:
Router# show memory io
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
6132DA0 59264 6132664 6141520 0 0 600DDEC 3FCF0 *Packet Buffer*
600DDEC 500 600DA4C 600DFE0 0 6132DA0 600FE68 0
600FE68 376 600FAC8 600FFE0 0 600DDEC 6011D54 0
6011D54 652 60119B4 6011FEO 0 600FE68 6013D54 0
614FCA0 832 614F564 614FFE0 0 601FD54 6177640 0
6177640 2657056 6172E90 0 0 614FCA0 0 0
Total: 2723244
Table97 show memory Field Descriptions—First Section
Field Description
Head Hexadecimal address of the head of the memory allocation chain.
Total(b) Sum of used bytes plus free bytes.
Used(b) Amount of memory in use.
Free(b) Amount of memory not in use.
Lowest(b) Smallest amount of free memory since last boot.
Largest(b) Size of largest available free block.
Table98 Characteristics of Each Block of Memory—Second Section
Field Description
Address Hexadecimal address of block.
Bytes Size of block (in bytes).
Prev. Address of previous block (should match the address on previous line).
Next Address of next block (should match the address on next line).
Ref Reference count for that memory block, indicating how many different processes are
using that block of memory.
PrevF Address of previous free block (if free).
NextF Address of next free block (if free).
Alloc PC Address of the system call that allocated the block.
What Name of process that owns the block, or “(fragment)” if the block is a fragment, or
“(coalesced)” if the block was coalesced from adjacent free blocks.