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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping]Jim, No. The "view" is just a character string (another accesID if you want) that will help the target understand who the initiator thinks it is talking too. The target will make-up the map accordingly. The view is in fact the "NAME of the VIEW". More than that - in fact the whole string can be used as a selector but we did not want to force the host name to be unique for the view as it is many times done in the "WWW" world (nevertheless we can't prevent it). Julo "Jim Hafner/Almaden/IBM" <hafner@almaden.ibm.com> on 02/10/2000 18:30:53 Please respond to "Jim Hafner/Almaden/IBM" <hafner@almaden.ibm.com> To: Julian Satran/Haifa/IBM@IBMIL cc: Subject: Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping] Julo, Are you suggesting that the host send to the target what it thinks the LUN->LU map should be (during the login process)? I think you call this LUN Map, the "view". I don't quite see what the point of this is. The initiator is fully authenticated to the target as is the target to the initiator (via whatever cryptographic or non-cryptographic schemes the security proposal defines). After that, the target knows whose talking and knows the map (based on configuration information established in any number of ways (Access Control commands in-band; vendor specific in-band or out-of-band). I don't see the point of the initiator sending its "view" to the target at any point. If the initiator sends an incorrect view, you've just created an error scenario which needs additional definition. In any case, the target will send its "view" for that initiator in REPORT LUNS SCSI command after login (which is actually the layer that cares about the LUN Map at all anyway). Jim Hafner julian_satran@il.ibm.com@ece.cmu.edu on 10-02-2000 02:09:56 AM Sent by: owner-ips@ece.cmu.edu To: ips@ece.cmu.edu cc: Subject: Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping] Jim, The "URL like" target address and view are sent o the target as part of the text-message at login. If authenthication is being done then this will be part of the message that follows the exchange that establishes the authenticated channel. Julo "Jim Hafner/Almaden/IBM" <hafner@almaden.ibm.com> on 29/09/2000 18:07:54 Please respond to "Jim Hafner/Almaden/IBM" <hafner@almaden.ibm.com> To: Julian Satran/Haifa/IBM@IBMIL cc: ips@ece.cmu.edu Subject: Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping] Julo, Yet another method for determining the mapping of LUs to LUNs for given initiator? You already have vendor-specific ways (in FC that will surely get ported to iSCSI), the T10 standardized way with AccessID enrollment or with a TransportID (for iSCSI, which is still TBD), and the login authentication process (however that ends up getting defined). Also, your comment implies that the URL is sent to the target in a mode similar to an http-type protocol. Where is this protocol defined in the draft? Is it part of the Text message in the login authentication? Jim Hafner julian_satran@il.ibm.com@ece.cmu.edu on 09-29-2000 06:14:44 AM Sent by: owner-ips@ece.cmu.edu To: ips@ece.cmu.edu cc: Subject: Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping] I would add that we wanted the path to be an additional identifier that the target could use to determine what collection of LUs to present to the initiator. Julo csapuntz@csapuntz-u1.cisco.com on 23/09/2000 05:00:33 Please respond to csapuntz@csapuntz-u1.cisco.com To: "IP Storage" <IPS@ece.cmu.edu> cc: (bcc: Julian Satran/Haifa/IBM) Subject: Re: SCSI URL scheme [WAS: Re: iSCSI: 2.2.6. Naming & mapping] Just for clarification... I was not proposing to add the extended URL scheme for the transport spec. It isn't necessary. In this thread, Doug makes an excellent point about LDAP being a superior mechanism for describing how to connect to the storage. Directory services such as LDAP, as Doug has pointed out, will be critical to managing large quantities of storage. A host can ask such a directory service for a list of storage devices it should mount and how to connect to those storage devices. The query against the directory server that returns this information can be based on machine ID, user ID, operating system ID, or even the owner's birthday. One of the things discovery will end up doing, no doubt, is defining LDAP schemas that describe how to connect to storage (i.e. use SCTP or TCP, what port, what target name, what LUN, what WWN, how to authenticate, etc.). However, there is one place where the transport protocol has to define a name: third party commands. There needs to be some kind of global name which the initiator can pass to the target. The name must be distillable into a string. The target must understand the name and be able to use the information to establish a connection to another target. One could say that the string that is passed is not specified by the standard but instead specified by some management software. I think this will lead to poor interoperability. The SCSI URL-type name is the current proposal for target name. Why is SCSI target name made up of a hostname + a path? Why is the hostname + path passed on connection setup? There are two reasons. I think NAT and IPv6 makes passing hostnames rather than addresses in protocols more desirable. Hostnames can be re-resolved as you cross addressing boundaries. The path is there so that the name can support multiple targets behind a single IP address without having to add entries to the DNS server. At Cisco, for example, I have no control over the local DNS servers and cannot add DNS entries for the ATAPI DVD and floppy in my computer. _Costa
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