SCSI Primary Commands - 2.pdf

More documents

Recommendations

Info

T10/1236-D Revision 20 18 July 2001The copy manager shall move data from the source devices to the destination devices as prescribed by thesegment descriptors. The specific commands issued by the copy manager to the source and destination deviceswhile processing the segment descriptors is vendor specific. Upon completion of an EXTENDED COPY commandthat returns GOOD status, the source and destination devices, particularly stream devices, shall be positioned atdeterministic locations such that the device may be repositioned to the same location by the application client withappropriate commands.7.2.2 Errors detected before starting processing of the segment descriptorsErrors may occur during processing of an EXTENDED COPY command before the first segment descriptor isprocessed. These conditions include CRC or parity errors while transferring the EXTENDED COPY command,invalid parameters in the CDB or parameter data, invalid segment descriptors, and inability of the copy manager tocontinue operating. In the event of such an exception condition, the copy manager shall:a) terminate the EXTENDED COPY command with CHECK CONDITION status; andb) set the VALID bit in the sense data to zero. The sense key shall contain the sense key code describing theexception condition (i.e.: not COPY ABORTED).7.2.3 Errors detected during processing of segment descriptorsErrors may occur after the copy manager has begun processing segment descriptors. These include invalidparameters in segment descriptors, invalid segment descriptors, unavailable targets referenced by targetdescriptors, inability of the copy manager to continue operating, and errors reported by source or destination targetdevices. If the copy manager receives a CHECK CONDITION status from one of the target devices, it shall recoverthe sense data associated with the exception condition and clear any ACA condition associated with the CHECKCONDITION status.If processing of a segment cannot complete because the copy manager is unable to establish communications witha target device, or because the target device does not respond to INQUIRY, or because the data returned inresponse to INQUIRY indicates an unsupported logical unit, then the EXTENDED COPY command shall be terminatedwith a CHECK CONDITION status. The sense key shall be set to COPY ABORTED and the additionalsense code shall be set to COPY TARGET DEVICE NOT REACHABLE.If processing of a segment cannot complete because the data returned in response to an INQUIRY commandindicates a device type that does not match the type in the target descriptor, then the EXTENDED COPYcommand shall be terminated with a CHECK CONDITION status. The sense key shall be set to COPY ABORTEDand the additional sense code shall be set to INCORRECT COPY TARGET DEVICE TYPE.If the copy manager has issued a command other than INQUIRY to a target device while processing anEXTENDED COPY command and the target device either fails to respond with status or responds with status otherthan BUSY, TASK SET FULL, ACA ACTIVE, or RESERVATION CONFLICT the condition shall be considered atarget device command failure. In response to a target device command failure the EXTENDED COPY commandshall be terminated with a CHECK CONDITION status. The sense key shall be set to COPY ABORTED and theadditional sense code shall be set to THIRD PARTY DEVICE FAILURE.If a target device responds to a command from the copy manager with a status of BUSY, TASK SET FULL, ACAACTIVE, or RESERVATION CONFLICT the copy manager shall either retry the command or terminate theEXTENDED COPY command as a target device command failure.NOTES2 The copy manager is assumed to employ a vendor specific retry policy that minimizes time consuming and/orfruitless repetition of retries.3 RESERVATION CONFLICT is listed only to give the copy manager leeway in multi-port cases. The copymanager may have multiple ports that are capable of reaching a target device, and there may be a third-party46 dpANS SCSI Primary Commands - 2 (SPC-2)
18 July 2001 T10/1236-D Revision 20reservation for one of these ports. The copy manager may need to try access from multiple ports to find onewith access.If a target device responds to an input or output operation with a GOOD status but less data than expected is transferred,then the EXTENDED COPY command shall be terminated with a CHECK CONDITION status. The sensekey shall be set to COPY ABORTED and additional sense code shall be set to COPY TARGET DEVICE DATAUNDERRUN. If an overrun is detected, then the EXTENDED COPY command shall be terminated with a CHECKCONDITION status. The sense key shall be set to COPY ABORTED and additional sense code shall be set toCOPY TARGET DEVICE DATA OVERRUN.Following an exception condition detected during segment descriptor processing, the copy manager shall:a) terminate the EXTENDED COPY command with CHECK CONDITION status;b) set the sense key code to COPY ABORTED;c) indicate the segment that was being processed at the time of the exception by writing the segment numberto third and forth bytes of the COMMAND-SPECIFIC INFORMATION field. The segment number is based on therelative position of the segment descriptor in the EXTENDED COPY parameter list. The first segmentdescriptor in the parameter list is assigned descriptor number zero, the second is assigned one, etc.;d) If any data has been written to the destination for the segment being processed at the time the erroroccurred, the residual for the segment shall be placed in the INFORMATION field, and the VALID bit shall beset to one. The residual count shall be reported in bytes if the peripheral device type in the destinationtarget descriptor is 03h, and in destination device blocks for all other device type codes. The residual countshall be computed by subtracting the number of bytes or blocks successfully written during the processingof the current segment from the number of bytes or blocks which would have been written if all commandshad completed with GOOD status and all READ commands had returned the full data length requested.When computing the residual count, the copy manager shall include only the results of commandssuccessfully completed by a destination device, specifically commands completed by a destination devicewith a GOOD status or with a CHECK CONDITION status and the EOM bit set to one in the sense data. Ifthe copy manager has used out of order transfers the residual count shall be based solely on thecontiguous successfully completed transfers starting at relative byte zero of the segment (i.e., anysuccessfully completed transfers farther from relative byte zero than the first incomplete or unsuccessfultransfer shall not contribute to the computation of the residual count). If no data has been written to thedestination for the segment being processed at the time the error occurred, then the VALID bit shall be setto zero and the contents of the INFORMATION field are not defined. Segment descriptors that do not specifya transfer count shall not have a valid residual count returned;e) If the exception condition is reported by the source logical unit, then the first byte of the COMMAND-SPECIFICINFORMATION field shall specify the starting byte number, relative to the first byte of sense data, of an areathat contains the status byte and sense data delivered to the copy manager by the source logical unit. Thestatus byte and sense data shall not be modified by the copy manager or device server. A zero valueindicates that no status byte and sense data is being returned for the source logical unit;f) If the exception condition is reported by the destination logical unit, then the second byte of theCOMMAND-SPECIFIC INFORMATION field shall specify the starting byte number, relative to the first byte ofsense data, of an area that contains the status byte and sense data delivered to the copy manager by thedestination logical unit. The status byte and sense data shall not be modified by the copy manager ordevice server. A zero value indicates that no status byte and sense data is being returned for the destinationlogical unit;g) If segment processing is terminated because a target device is unreachable or as the result of a targetcommand failure, then the SENSE-KEY SPECIFIC field shall be set as described in 7.20.3, with the FIELDPOINTER field indicating the first byte of the target descriptor that identifies the target; andh) If, during the processing of a segment descriptor, the copy manager detects an error in the segmentdescriptor, then the SENSE-KEY SPECIFIC field shall be set as described in 7.20.3, with the FIELD POINTERfield indicating the byte in error. The FIELD POINTER field may be used to indicate an offset into either theparameter data or the segment descriptor. The SD bit is used to differentiate between these two cases.The SD bit shall be set to zero to indicate the FIELD POINTER field contains an offset from the start of thedpANS SCSI Primary Commands - 2 (SPC-2) 47
Page 1 and 2:
dpANSProjectT10/1236-DRevision 2018
Page 3:
DraftANSI (r)NCITS.351:200xAmerican
Page 6 and 7:
T10/1236-D Revision 20 18 July 2001
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15: T10/1236-D Revision 20 18 July 2001
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
show all

SCSI Primary Commands - 2.pdf

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?