Jumbo frames and network utilization

certhelpcerthelp Posts: 191Member
I have VMware hosts under ESXi 4.1 U2. I have enabled jumbo frames on the hosts, a file server (2k8 R2), and laptop running Win 7. But, when I transfer files (large and small), the network utilization is only about 8% to 26% on the file server and consistently between 50% and 60% on the laptop. What's strange is when I ping with large packet size from the ESXi hosts, the pings fail but succeed to the file server.

All are connected to the same PowerConnect 5424 gigabit switch.

Laptop is at 192.168.1.69 and the file server is at 192.168.1.40
~ # vmkping -s 100 -d 192.168.1.69PING 192.168.1.69 (192.168.1.69): 100 data bytes


--- 192.168.1.69 ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss
~ # vmkping -s 8972 -d 192.168.1.40
PING 192.168.1.40 (192.168.1.40): 8972 data bytes
8980 bytes from 192.168.1.40: icmp_seq=0 ttl=128 time=1.288 ms
8980 bytes from 192.168.1.40: icmp_seq=1 ttl=128 time=1.200 ms
8980 bytes from 192.168.1.40: icmp_seq=2 ttl=128 time=1.259 ms



The network utilization on laptop is higher (above pic) than on file server and finishes file uploads from it are faster. The ping fails with any size specified and don't fragment option when pinging to laptop.

The file server has Intel PRO/1000 MT quad port NICs while the laptop has Integrated Intel 82579LM Gigabit NIC. The hosts have Intel Pro ET quadport gigabit NIC cards.

Also, the Integrated Broadcom NIC on the Hosts doesn't seem to support jumbo frames under ESXi 4.1. Do I need any custom driver added to the ESXi installation?

Can anyone shed some light on this?

Thanks.

Comments

  • it_consultantit_consultant Posts: 1,903Member
    Turn off jumbo frames and walk away. Seriously. The only reason to seriously consider using jumbo frames [where they will benefit you the most] is on an iSCSI HBA where the storage system and intermediate switch all support jumbo frames. Jumbo frames are more efficient for that type of traffic.
  • certhelpcerthelp Posts: 191Member
    Turn off jumbo frames and walk away. Seriously. The only reason to seriously consider using jumbo frames [where they will benefit you the most] is on an iSCSI HBA where the storage system and intermediate switch all support jumbo frames. Jumbo frames are more efficient for that type of traffic.

    Without jumbo frames, the same file copy takes about 3 times longer. I am also using the software iSCSI.
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