Supermicro X8DTH-6: Only ~250MiB/s from RAID<->RAID over 10GbE?

Justin Piszcz
2011-02-05T19:35:52Z

Hi,

I have two identical X8DTH-6's, each with 5520s XEONS..

=== RAID
Two 3ware RAID-0's (testing only) with 24 drives (2TB WD).
Read: 1.2Gbyte/sec
Write: 1.2Gbyte/sec

=== NETWORK
When I run iperf between the two 10GbE interfaces, I get 1.1-1.2Gbyte/sec.
MTU=9000 on both hosts.

== COPY OVER NETWORK
When I copy using cp/NFS, tar/nc, etc.. I only see an average of about
250MiB/s, I also have two desktop boards (8GB ram/ea) from which I get
500-550MiB/s from (the raid is slower on the desktop boards, it gets what
the RAID can read it), how come these server boards cannot push > 1Gbyte/sec
sustained?

I know on this board:
CPU1 => SLOT 1,2,3
CPU2 => SLOT 4,5,6,7

The RAID card is plugged into 2 (CPU1)
The 10GbE card is plugged into 6 (CPU2)

Should both cards be plugged into the same set of slots controlled by the
same CPU?

Has anyone experienced anything like this before, e.g., > 1Gbyte/sec read
& write for network and 3ware RAID but when using them in combination, it
is slow.

OS = CentOS 5.5 x86_64
Filesystem = XFS
NIC = 10GbE AT2 Server Adapter

No single component is < 1Gbyte/sec but when data is transferred from
hostA to hostB, then it degrades to 250MiB/s.

Justin.