Re: Reg: Bidirectional command format ?
Neil Wanamaker <[email protected]>
| Newsgroups | gmane.ietf.ips |
|---|---|
| Message-ID | <[email protected]> |
At 02:26 PM 6/19/2006, Paul von Behren wrote: >Eddy Quicksall wrote: > >>Is anyone aware of any bidi SCSI commands? > > >Look at the OSD command set (on the T10 site). I think all the OSD >commands are bidi. I think that's the only command set now with bidi commands. Try XDWRITEREAD in SBC-2. Neil Wanamaker PMC-Sierra 100-2700 Production Way Burnaby, BC >Paul > >> >>Eddy >> >>----- Original Message ----- From: "William Studenmund" >><[email protected]> >>To: "Praveen Madhavan" <[email protected]> >>Cc: <[email protected]> >>Sent: Friday, June 16, 2006 3:04 PM >>Subject: Re: [Ips] Reg: Bidirectional command format ? >> >> >>>-----BEGIN PGP SIGNED MESSAGE----- >>>Hash: SHA1 >>> >>>On Jun 16, 2006, at 5:37 AM, Praveen Madhavan wrote: >>> >>>>Hi Folks, >>>> >>>>Can any one point me the frame format of bidirectional command in >>>>case of iSCSI & FCP ?.. I was trying to route bidirectional command >>>>recv'd from iSCSI initiator to FC Target.. >>>> >>>>Here is the iSCSI PDU format for bi-direct command recv from initiator >>>>---------------------------------------------------------------------- >>>>-------------------------- >>>>| BHS >>>>(48bytes) >>>> | >>>>| R & W bit set to >>>>ONE, | >>>>| Expected xfer len = >>>>0x200 | >>>>| Total AHS Length = 2 >>>>(8bytes) | >>>>| SCSI CDB = Write(10) Transfer length = 00 01 ( 512 bytes) | >>>> >>>>---------------------------------------------------------------------- >>>>--------------------------| >>>>| AHS ( 8 >>>>bytes) >>>> | >>>>| Expected Read data length = 0x200(512 >>>>bytes) | >>>>---------------------------------------------------------------------- >>>>---------------------------- >>>> >>>>Here is the FCP format for bi-direct command that i frame for >>>>sending it to target. >>>> >>>>---------------------------------------------------------------------- >>>>-------------------------- >>>>| FC-Header >>>>(24bytes) | >>>>|--------------------------------------------------------------------- >>>>--------------------------- >>>>| FCP-Header(36 >>>>bytes) | >>>>| R & W bit set to >>>>ONE, | >>>>| Additional CDB length = >>>>0 | >>>>| SCSI CDB = Write(10) Transfer length = 00 01 ( 512 >>>>bytes) | >>>>| FCP_DL = 0x200 ( 512 >>>>bytes) | >>>>| FCP_BIDIRECTIONAL_READ_DL = 0x200(512) | >>>> >>>>---------------------------------------------------------------------- >>>>---------------------------| >>>> >>>>Well, I am not quite sure about the CDB values in case Bidir >>>>commands.. >>>>Will Bi directional cmds use Write CDB(10) or Read CDB (10) ? .. >>> >>> >>>No. Read and Write in normal sizes (6, 10, 12, 16) are unidirectional. >>> >>>Each specific command has either no data phase (test unit ready), >>>has at most a data-out phase (Write for instance), at most a >>>data-in phase (Read), or is bidirectional. >>> >>>>How can i control following bidi- operation in case of iSCSI & FCP ? >>>>1.bidirectional command with read before write operation >>>>2.bidirectional command with write before read operation >>> >>> >>>You really don't need to do anything different for BiDi commands, >>>other than be able to keep both a Write and a Read residual. As you >>>note, the SCSI Command Request will indicate what data phases the >>>initiator expects, you need only map them along. >>> >>>How does the target announce/control data flow in FCP? You need only >>>pass that information on to the iSCSI layer. If the FCP target sends >>>you data, then you send the initiator a bunch of Data-In PDUs. >>>However it is that FCP controls data openings translates into R2Ts >>>to the iSCSI initiator. >>> >>>Take care, >>> >>>Bill >>>-----BEGIN PGP SIGNATURE----- >>>Version: GnuPG v1.4.1 (Darwin) >>> >>>iD8DBQFEkwDZDJT2Egh26K0RAjqYAJ4yfTh+dkihI/Ha0RGhZN5NJ22zUQCfRc1L >>>7fPzAAxZZUa3mX6JsaEMPYs= >>>=a55F >>>-----END PGP SIGNATURE----- >>> >>>_______________________________________________ >>>Ips mailing list >>>[email protected] >>>https://www1.ietf.org/mailman/listinfo/ips >> >>_______________________________________________ >>Ips mailing list >>[email protected] >>https://www1.ietf.org/mailman/listinfo/ips > > >_______________________________________________ >Ips mailing list >[email protected] >https://www1.ietf.org/mailman/listinfo/ips Neil Wanamaker [email protected] 512.917.9712 _______________________________________________ Ips mailing list [email protected] https://www1.ietf.org/mailman/listinfo/ips