User Guide
NetXtreme II
January 2010
Bro a d c o m Co rp o r a ti o n
Document
ENGSRVT52-CDUM100-R
Linux iSCSI Offload
Page 139
M
AXIMIZE
O
FFLOAD
I
SCSI C
ONNECTIONS
With default driver parameters set, which includes 128 outstanding commands, bnx2i can offload a maximum of 28 iSCSI
connections. This is not a hard limit, but just a simple on-chip resource allocation math. bnx2i will be able to offload > 28
connections by reducing the shared queue size which in turn limits the maximum outstanding tasks on a connection. See
Setting Values for Optional Properties
for information on sq_size and rq_size. Driver logs the following message to syslog
when the maximum allowed connection offload limit is reached - “bnx2i: unable to allocate iSCSI context resources”
L
INUX
I
SCSI O
FFLOAD
FAQ
•
Not all Broadcom NetXtreme II adapters support iSCSI offload.
•
The iSCSI session will not recover after a hot remove and hot plug.
•
For MPIO to work properly, iSCSI nopout should be enabled on each iSCSI session. Refer to open-iscsi documentation
for procedures on setting up
noop_out_interval
and
noop_out_timeout
values.
•
In the scenario where multiple CNIC devices are in the system and the system is booted via Broadcom’s iSCSI boot
solution, ensure that the iscsi node under /etc/iscsi/nodes for the boot target is bound to the NIC that is used for booting.
