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Broadcom 5709C - Bad read performance
I have a problem ;)
Got a new PS6100E with 1 TB NL-SAS drives (RAID6). Tried to connect a windows 2008 r2 server with 2 dual-port nics (Broadcom 5709C).
I tried iSCSI Offload Engine and the "normal" network driver with microsoft Software initiator.
HIT is installed an works fine (4 path to each volume).
Jumbo frames are enabled on all ports.
Upload speed to the array seems fine (> 90 MB/s) but the download speed (copy with windows explorer) ist realy bad. (< 10MB).
While copying files from the PS6100 to the local storrage in the server (slow) the "tcp-retransmit" value in SAN-HQ rises from <0,1 to 2 - 3%.
I think the problem is on the server side (nic, driver, settings)
Can someone tell me, which firmware and driver i have to use with my Broadcom 5709C, should i use the iSCSI HBA-Mode oder NIC-Mode, which settings should i use on the NIC-properties.
Where can i get "older" drivers for the nics? On Dell page are only the latest ...
regards
michael
You are right, in Switch Configuration Jumbo Frames are "enabled" for the whole switch.
Do you think that the latest firmware and driver from the broadcom website will let me use MTU 9000 in iSCSI Offload Engine?
I Would like Dell to publicate documents with the "best" settings for famous NICs.
Sometimes you read about disabling LSO or all offload features, but there is no document from dell which tells me the best settings for my NIC (in NIC-Mode).
Here is a config for our switches with vlan1 an jumbo: en.community.dell.com/.../configuring-a-powerconnect-5424-or-5448-switch-for-use-with-an-iscsi-storage-system.aspx
With Powerconnect 5xxx i thinks there will be nor problem with jumbos on vlan1. Its a iSCSI Switch with only iSCSI traffic an only one vlan.
In an equallogic configuration guide from 2009 they only wrote the commands to enable jumbo frames on this switch.
For some cisco switches they wrote that vlan1 can not be used for jumbo frames.
A Dell engineer installed our first ps6000e with two of these switches an left all ports in vlan1(default).
Was this a mistake?
michael
porschenm
26 Posts
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Posted August 29th, 2012 15:00
I disabled Jumbos on the Broadcom and it works fine.
On the switches (dell iscsi switches) all ports are configured with flow control and mtu 9000.
A dell engineer configured it and told us to set all nics to mtu 9000 if we get new servers.
Our vSphere Cluster works fine with mtu 9000 ...
I thought, that jumbo frames are a "must have" for high performance iscsi .
Thanks!