Read performance problem with iSCSI

[Nicolas Morey-Chaisemartin]

Hi,

I am not sure if this is the right place, some my apologies if I'm mistaken.
I have a FreeBSD 8.0 stable running on an amd64 machine (with the last 2.2.4 iscsi tarball from http://www.cs.huji.ac.il/~danny/ftp/freebsd/). 
It is connected to a Thecus N5500 pro using iSCSI.

I've configured using the tutorial all over Google and it works !
Using dd, I get 52MB/s write speed which is a bit lower than expected but still allright. However reading is deadly slow.
At best, I reached something like 8MB/s which is unacceptable.

After looking through Google and old mailing list mails, I made sure I have enough tags but increasing the value did not really help.
All the other tips i could find were about fine tuning and nothing to gain a factor of 6 or 7...

Has any one see this problem or can someone point me in a direction to look for?

One weird thing I noticed while playing with camcontrol is I get an error on access rate.
Sun# camcontrol inquiry da0
pass0: <NAS iSCSI-VDISK 0> Fixed Direct Access SCSI-4 device 
pass0: Serial Number     
camcontrol: error getting transfer settings


Thanks in advance

Nicolas


Here's my config (feel free to ask for more info):
Sun# cat /etc/iscsi.conf 
stephano {
       authmethod      = None
       TargetName      = iqn.2010-5.com.****:RAID.iscsi0.vg0.store
       TargetAddress   = 10.0.2.55:3260,1
       tags	       = 64
}

Sun# sysctl net.iscsi_initiator
net.iscsi_initiator.driver_version: 2.2.4
net.iscsi_initiator.isid: €DIB00
net.iscsi_initiator.sessions: 1
net.iscsi_initiator.0.targetname: iqn.2010-5.com****:RAID.iscsi0.vg0.store
net.iscsi_initiator.0.targeaddress: 10.0.2.55
net.iscsi_initiator.0.stats: recv=46460 sent=46460 flags=0x0000039f pdus-alloc=0 pdus-max=5 cws=33 cmd=b57b exp=b57b max=b59b stat=b57b itt=b57b
net.iscsi_initiator.0.douio: 0
net.iscsi_initiator.0.pid: 1608