Description

Why we see high buffer memory on E3-FPC type 2?

Symptoms


Solution

The boards that are based on MPC85xx processor do use more buffers to receive packets, so higher heap usage is expected. Most of these buffers are owned by receive part of the ethernet driver and just seat in the queue waiting for the incoming data, in other words they are not leaked.

Here are the high buffer outputs without any traffic

lab@Einstenium-M320> show chassis hardware detail
Hardware inventory:
Item             Version  Part number  Serial number     Description
Chassis                                71103             M320
Midplane         REV 05   710-009120   RB5259            M320 Midplane
Routing Engine 0 REV 10   740-008883   P11123911393      RE-4.0
  ad0     245 MB  STI Flash 7.3.0      STI1J9D606257154901 Compact Flash
  ad1   38154 MB  FUJITSU MHV2040AS    NT14T6828NK0      Hard Disk
Routing Engine 1
CB 0             REV 07   710-009115   JL5995            M320 Control Board
CB 1             REV 07   710-009115   JN0782            M320 Control Board
FPC 0            REV 07   710-016170   WL2586            M320 E3-FPC Type 2 
  PIC 0          REV 09   750-011800   JX6418            8x 1GE(LAN), IQ2
    Xcvr 0       REV 01   740-011613   PCC4LJP           SFP-SX
    Xcvr 1       REV 01   740-011782   P8E1Q8Z           SFP-SX
    Xcvr 2                NON-JNPR     PE12B5B           SFP-SX
    Xcvr 3       REV 01   740-011782   PAN53T2           SFP-SX
    Xcvr 5       REV 01   740-013111   7447631           SFP-T
    Xcvr 6       REV 01   740-011613   PCD4FW4           SFP-SX
    Xcvr 7       REV 01   740-011613   PCE03YV           SFP-SX
  PIC 1          REV 11   750-007745   NC4565            4x OC-3 SONET, SMIR
  I3MB A         REV 04   710-016681   WL2713            M320 E3-FPC I3 Mez Board
  I3MB B         REV 04   710-016681   WL2671            M320 E3-FPC I3 Mez Board
lab@Einstenium-M320> show chassis fpc
                  Temp    CPU Utilization (%)    Memory     Utilization (%)
Slot   State       (C)    Total   Interrupt      DRAM (MB)   Heap    Buffer
0      Online      46       3        0           1024         8       74  
1      Online      42       1        0           256          12      49
2      Online      39       1        0           1024         2       49
lab@Einstenium-M320> start shell pfe network fpc0

SFPC0(Einstenium-M320 vty)# sh heap
ID     Base      Total(b)   Free(b)    Used(b)    %     Name
--     --------  ---------  ---------  ---------  ---   -----------
0      410c9a68  1004716792 922597044  82119748   8      Kernel
1      7cef5d60  16777216   4268320    12508896   74     Uncached 
2      7fefffe0  1048560    1048560    0          0      Blob
3      7def5d60  33595288   33595288   0          0      ISSU scratch

If there is a problem in allocating packets for the sheaves, then in the log messages "Packet allocation failure" error message are seen. These error messages will help to identify if there is actually memory shortage or not. Until we dont see any error messages in the logs this is found to be normal.