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Article State

in progress

Article Number

KB-20180222093745

Product

DellEMC, EMC, Data Domain, DataDomain, DDOS
SummaryHow to check and modify data domain network interface statistics and settings


Language

EN

DE

Issue

Data Domain: network performance issues, network retransmission, network retransmit, tcp retransmission,

FlowControll-Transmit-STOP (FC-T-S)
FlowControll-Transmit-Resume (FC-T-R)
FlowControll-Receive-Stop (FC-R-S)
FlowControll-Receive-Resume (FC-R-R)

Cause

You've detected strange network behaviors and your plan is it to check network interface port statistics and you'll modify settings like "flow controll" for further tests.

Solution

  1. SSH connection to data domain
  2. Enter SE mode: "To elevate from admin mode to SE mode a password is required. By default, it is the serial number of the Data Domain system. The following commands can be used to elevate from admin mode to SE mode"
    1. "priv set se"

      1. Retrieve the Data domain serial number:
      DD@DD690_MSC# system show serial
      Serial number: 0F1234043
      
      2. Run the command ‘priv set se’ to change the mode to SE
      Entering DataDomain  SE Mode
      DD@DD690_MSC# #priv set se
       
      3. When prompted for password enter the serial number as the password.
      Avamar-DD@<DD_server># priv set se
      Enter system password:
      SE@DD690_MSC##
       
      4. If applicable, to switch back to admin mode from SE mode the following command can be used:
      SE@<DD_server>## priv set admin      
      DD@<DD_server>#
  3. Check current NIC config; identify the adapter you'll check
    1. "net show config"

      SE@DD7200## net show config ethMa
      ethMa     Link encap:Ethernet  HWaddr 00:60:16:49:F5:80
                inet addr:172.30.128.11  Bcast:172.30.255.255  Mask:255.255.0.0
                inet6 addr: fe80::260:16ff:affe:f580/64 Scope:Link
                UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
                RX packets:0 errors:0 dropped:0 overruns:0 frame:0
                TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
                collisions:0 txqueuelen:1000
                RX bytes:4522440 (4.3 MiB)  TX bytes:14021699 (13.3 MiB)
                Interrupt:16
  4. Check current NIC Pause/Flow-Controll settings
    1. "se ethtool -a"

      SE@DD7200## se ethtool -a ethMa
      Pause parameters for ethMa:
      Autonegotiate:  on
      RX:             off
      TX:             off
      
      
      
  5. Cange current NIC Pause/Flow-Controll settings
    1. "se ethtool -A"

      SE@DD7200## se ethtool -A ethMa rx on, tx on
      
      

      Change current NIC Pause / Flow-Control settings:

      The network connection is lost for a short time !!!

      The change is lost after a system reboot !!!

      FlowControll settings can't changed via GUI / Webinterface, SSH and SE mode is required!

  6. We suggest to pic up a dedicated szenario and collect all informations in a retransmission matrix:


Workaround

Notes

The receiving side sends an XOFF character over its Tx line to tell the transmitting side to stop transmitting, and sends an XON character over its Tx line to tell the transmitting side to resume transmitting.