Karen Xie wrote:
> [PATCH 3/3 2.6.29] cxgb3i -- documentation
> 
> From: Karen Xie <k...@chelsio.com>
> 
> - document cxgb3i driver's capablity and setup steps to be used with
>   open-iscsi initiator.
> 
> Signed-off-by: Karen Xie <k...@chelsio.com>
> ---
> 
>  Documentation/scsi/cxgb3i.txt |   81 
> +++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 81 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/scsi/cxgb3i.txt
> 
> 
> diff --git a/Documentation/scsi/cxgb3i.txt b/Documentation/scsi/cxgb3i.txt
> new file mode 100644
> index 0000000..9456013
> --- /dev/null
> +++ b/Documentation/scsi/cxgb3i.txt
> @@ -0,0 +1,81 @@
> +Chelsio S3 iSCSI Driver for Linux
> +
> +Introduction
> +============
> +
> +The Chelsio T3 ASIC based Adapters (S310, S320, S302, S304, Mezz cards, etc.
> +series of products) supports iSCSI acceleration and iSCSI Direct Data 
> Placement

                       support

> +(DDP) where the hardware handles the expensive byte touching operations, such
> +as CRC computation and verification, and direct DMA to the final host memory
> +destination:
> +
> +     - iSCSI PDU digest generation and verification
> +
> +       On transmitting, Chelsio S3 h/w computes and inserts the Header and
> +       Data digest into the PDUs.
> +       On receiving, Chelsio S3 h/w computes and verifies the Header and
> +       Data digest of the PDUs.
> +
> +     - Direct Data Placement (DDP)
> +
> +       S3 h/w can directly place the iSCSI Data-In or Data-Out PDU's
> +       payload into pre-posted final destination host-memory buffers based
> +       on the Initiator Task Tag (ITT) in Data-In or Target Task Tag (TTT)
> +       in Data-Out PDUs.
> +
> +     - PDU Transmit and Recovery
> +
> +       On transmitting, S3 h/w accepts the complete PDU (header + data)
> +       from the host driver, computes and inserts the digests, decomposes
> +       the PDU into multiple TCP segments if necessary, and transmit all
> +       the TCP segments onto the wire. It handles TCP retransmission if
> +       needed.
> +
> +       On receving, S3 h/w recovers the iSCSI PDU by reassembling TCP

             receiving,

> +       segments, separating the header and data, calculating and verifying
> +       the digests, then forwards the header to the host. The payload data,

                            forwarding

> +       if possible, will be directly placed into the pre-posted host DDP
> +       buffer. Otherwise, the payload data will be sent to the host too.
> +
> +The cxgb3i driver interfaces with open-iscsi initiator and provides the iSCSI
> +acceleration through Chelsio hardware wherever applicable.
> +
> +Using the cxgb3i Driver
> +=======================
> +
> +The following steps need to be taken to accelerates the open-iscsi initiator:
> +
> +1. Load the cxgb3i driver: "modprobe cxgb3i"
> +
> +   The cxgb3i module registers a new transport class "cxgb3i" with 
> open-iscsi.
> +
> +   * in the case of recompiling the kernel, the cxgb3i selection is located 
> at
> +     Device Drivers
> +             SCSI device support --->
> +                     [*] SCSI low-level drivers  --->
> +                             <M>   Chelsio S3xx iSCSI support
> +
> +2. Create an interface file located under /etc/iscsi/ifaces/ for the new
> +   transport class "cxgb3i".
> +
> +   The content of the file should be in the following format:
> +     iface.transport_name = cxgb3i
> +     iface.net_ifacename = <ethX>
> +     iface.ipaddress = <iscsi ip address>
> +
> +   * if iface.ipaddress is specified, <iscsi ip address> needs to be either 
> the
> +     same as the ethX's ip address or an address on the same subnet. Make
> +     sure the ip address is unique in the network.
> +
> +3. edit /etc/iscsi/iscsid.conf
> +   The default setting for MaxRecvDataSegmentLength (131072) is too big, 
> search

                                                                       big;

> +   and replace all occurances of "xxx.iscsi.MaxRecvDataSegmentLength" to be a

                      occurrences

> +   value no bigger than 15872 (for example 8192):
> +
> +     discovery.sendtargets.iscsi.MaxRecvDataSegmentLength = 8192
> +     node.conn[0].iscsi.MaxRecvDataSegmentLength = 8192
> +
> +4. To direct open-iscsi traffic to go through cxgb3i's accelerated path,
> +   "-I <iface file name>" option needs to be specified with most of the
> +   iscsiadm command. <iface file name> is the transport interface file 
> created
> +   in step 2.


HTH.

~Randy


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To post to this group, send email to open-iscsi@googlegroups.com
To unsubscribe from this group, send email to 
open-iscsi+unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/open-iscsi
-~----------~----~----~----~------~----~------~--~---

Reply via email to