Router RAM usage

Question

Hi,
i have a Question to Router RAM usage.
My Router have 512MB of Memory.
When i do a "show version" I get this otput:
Cisco ********* processor with 491520K/32768K bytes of memory.
This means 491MB for CPU and 32MB for IO.
Now i do a "show memory" and get this output:
                Head    Total(b)     Used(b)     Free(b)   Lowest(b)  Largest(b)
Processor   6353EB60   430707644    14276428   416431216   416363448   413930428
      I/O    E000000    33554432     1884520    31669912    31669912    31669884
Now here are only 430MB Total RAM for the Processor. Why this? What is with the other 60MB Memory? How does these values are in context with the Output of a  "show region"?
Region Manager:
      Start         End     Size(b)  Class  Media  Name
0x0E000000  0x0FFFFFFF    33554432  Iomem  R/W    iomem
0x60000000  0x7DFFFFFF   503316480  Local  R/W    main
0x60008EF8  0x6204F18B    33841812  IText  R/O    main:text
0x62050000  0x6303FE1F    16711200  IData  R/W    main:data
0x6303FE20  0x6353EB5F     5238080  IBss   R/W    main:bss
0x6353EB60  0x6453EB5F    16777216  Local  R/W    main:heap
0x7D000000  0x7DFFFFFF    16777216  Local  R/W    main:heap
0x7E000000  0x7FFFFFFF    33554432  Iomem  R/W    iomem:(iomem_cwt)
0x80000000  0x8DFFFFFF   234881024  Local  R/W    main:(main_k0)
0xA0000000  0xADFFFFFF   234881024  Local  R/W    main:(main_k1)
Thank in advance
Thomas

Answer 1

hello Thomas,
in order to understand the difference between both output, i would highly recommend you to go through the following mentioned example:
the output of the show version indicate the physical amount of memory... however, the following mentioned memory summary indicate the >>>>>> allocated + total == process memeory...
Router>show memory summary
            Head       Total (b)   Used (b)  Free (b)   Lowest (b)  Largest (b)
Processor   60AB4ED0   5550384     2082996   3467388    3464996     3454608
I/O         40000000   16777216    1937280   14839936   14839936    14838908
Total = the total amount of memory available after the system image loads and builds its data structures.
Used = the amount of memory currently allocated.
Free = the amount of memory currently free.
Lowest = the lowest amount of free memory recorded by the router since it was last booted.
Largest = the largest free memory block currently available.
Here is what you can learn from the show processes memory command output:
Router>show processes memory
Total: 3149760, Used: 2334300, Free: 815460
PID   TTY   Allocated    Freed      Holding    Getbufs    Retbufs   Process
0     0     226548       1252       1804376    0          0         *Initialization*
0     0     320          5422288    320        0          0         *Scheduler*
0     0     5663692      2173356    0          1856100    0         *Dead*
1     0     264          264        3784       0          0         Load Meter
2     2     5700         5372       13124      0          0         Virtual Exec
3     0     0            0          6784       0          0         Check heaps
4     0     96           0          6880       0          0         Pool Manager
5     0     264          264        6784       0          0         Timers
Allocated = the total amount of bytes that have been allocated by the process since the router booted...
Total = the total amount of memory available after the system image loads and builds its data structures.
so if you add the above allocated memory to the Total amount of memory, this should be equal to the process Pool >>> physical Dram...
please refer to the following link for more info:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00800a6f3a.shtml
hope this helps...
thanks,
/Osama