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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: iSCSI version 20 draftSorry to belabor this, but the wording about the affects of connection loss didn't end up like Mallikarjun's final recommendation. Upon further discussion, we think this would be better: If the tasks terminated in the above cases are SCSI tasks, they must be internally terminated as if with CHECK CONDITION status. This enables ordering to be maintained correctly with respect to commands on other connections when ACA is enabled. This enables ordering to be maintained correctly with respect to commands on other connections of the same I_T nexus when ACA is enabled (i.e., commands waiting to be processed after those terminated are blocked due to the ACA) - see [SAM-3] and [SPC-3]. After the tasks are terminated, the device server shall report a unit attention condition with an additional sense code of COMMANDS CLEARED BY TRANSPORT PROTOCOL EVENT on the next command processed on any connection for each affected I_T_L nexus. This enables ordering to be maintained correctly with respect to commands on other connections of the same I_T nexus when unit attention interlock is enabled (i.e., commands waiting to be processed after those terminated are blocked due to the unit attention interlock) - see [SAM-3] and [SPC-3]. The first paragraph explains why the "CHECK CONDITION" part is important for the internally terminated tasks. If they were allowed to terminate as if they had "GOOD" status, they wouldn't invoke ACA. The second paragraph explains the unit attention that must appear on the next command on the wire (and lists the additional sense code to use). This is not an additional sense code for an internal-only command status, so is appropriate for iSCSI to mention. We'll assign that code in SPC-3. The text in iscsi-20 is: 6.5 Implicit termination of tasks ... If the tasks terminated in the above cases a), b, c) and d)are SCSI tasks, they must be internally terminated as if with CHECK CONDITION status. This status is only meaningful for appropriately handling the internal SCSI state and SCSI side effects with respect to ordering because this status is never communicated back as a terminating status to the initiator. However additional actions may have to be taken at SCSI level depending on the SCSI context as defined by the SCSI standards (e.g., queued commands and ACA, UA for the next command on the I_T nexus in cases a), b), and c) etc. - see [SAM] and [SPC3]). 10.14.5 Implicit termination of tasks ... If the tasks terminated in any of the above cases are SCSI tasks, they must be internally terminated as if with CHECK CONDITION status. This status is only meaningful for appropriately handling the internal SCSI state and SCSI side effects with respect to ordering because this status is never communicated back as a terminating status to the initiator. However additional actions may have to be taken at SCSI level depending on the SCSI context as defined by the SCSI standards (e.g., queued commands and ACA, UA for the next command on the I_T nexus in cases a), b), and c) etc. - see [SAM] and [SPC3]). -- Rob Elliott, elliott@hp.com Hewlett-Packard Industry Standard Server Storage Advanced Technology https://ecardfile.com/id/RobElliott -----Original Message----- From: Julian Satran [mailto:Julian_Satran@il.ibm.com] Sent: Sunday, January 19, 2003 11:52 PM To: internet-drafts@ietf.org Cc: ips@ece.cmu.edu; Allison Mankin Subject: iSCSI version 20 draft On behalf of the team of authors and as part of the IETF-IPS working group I submit a draft for immediate publication. The text and pdf versions can be found at: http://www.haifa.il.ibm.com/satran/ips/draft-ietf-ips-iscsi-20.txt http://www.haifa.il.ibm.com/satran/ips/draft-ietf-ips-iscsi-20.pdf This version completely replaces: draft-ietf-ips-iscsi-19.txt and pdf The change marks are relative to version 19 and are clarifications as requested by Steve Bellovin and typo fixes. All AD concerns and the "nits" where (hopefully) addressed. Julian Satran - IBM Research Laboratory at Haifa
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