On Wednesday 06 December 2006 17:42, Jeremy Linton wrote: > On Wednesday 06 December 2006 16:50, Mike Christie wrote: > > > For iscsi, we could negotiate a value like MaxBurstLength which says > > > don't send commands with a payload larger than that size. I would guess > > > other transports have something similar. We have to check or make sure > > ... > > > Oh yeah the exception I am thinking about may not be max sectors exactly > > but something close like iscsi's MaxBurstLength limit. Maybe iscsi LLDs > > are supposed to be translating that iscsi limit to max_sectors in which > > case we are talking about the same thing. For this limit we do not want > > Sort of off topic, but the iSCSI MaxBurstLength doesn't set the max > transfer size, it simply is the amount of data that can be sent without a > R2T. If the transfer is larger then you have to wait for the R2T. In > practice it ends up controlling the _minimum_ amount of buffer space that > needs to be available _before_ the transfer starts, otherwise performace > sucks. Whops, Slight clarification, the MaxBurstLength is the max sent between R2T's what I described above is closer to the FirstBurstLength. What you guys are describing might better be the MaxRecvDataSegmentLength, but not really since that parameter should be hidden within the iSCSI driver. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
