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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: questions on the mapping in iSCSIBill, SRA's are returned by the target - the initiator only provides the descriptors; the idea is to let the target organize them as it sees fit (e.g., store the strings only once even if they originate from different initiators). I expect you would want to do as much work as possible and explore all descriptors. However finding out that a descriptor is bad can happen even after mapping. I refrained in fact specifying when will the name-to-address mapping be done (lazy or eager). I assume that unmapping should not have any effect on outstanding I/O - but I will make a not to clarify this point. Good luck with the implementation and thanks, Julo Bill Main <wmain@gis.net> on 21/07/2000 00:34:30 Please respond to bill.main@bigfoot.com To: ipSCSI list <ips@ece.cmu.edu> cc: (bcc: Julian Satran/Haifa/IBM) Subject: questions on the mapping in iSCSI Folks- Been working on trial implementation of iSCSI as it seems to me the easiest way to find loose threads in a new spec. couple of items have showed up so far: Question with regard to the mapping. I see latest spec descriptors that move from initiator to host but the response to mapping has little data in it other than status. Who generates the SRA's for the host to use. Are the SRA's part of the descriptor and the host is therefore informing the target what LUN id it will use for this "view"? Or should the SRA be returned from the target to inform the host what SRA to use to reach the desired view? If so the data layout needs updating to accommodate this. Next, multiple descriptors are allowed in the map command. What action should be taken if one is bad? Do the others and respond with failure or disallow others from succeeding? or should we limit the map command to single descriptor? I am thinking also of the poor sys admin trying to fix a broken mount command. Next, on the unmapping. What happens when an unmapping is done and outstanding IO's are pending on the device? in flight? Does the target can them or let them complete? It is not clear, but I presume the response to the unmap occurs after the IO's are either completed or aborted and abort is confirmed by the hardware at the target end. Is this correct? -Bill
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