From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aron Zeh" Subject: Re: [RFC]: 64 bit LUN/Tags, dummy device in host_queue, host_lock <-> LLDD reentrancy Date: Mon, 26 Aug 2002 10:02:47 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: List-Id: linux-scsi@vger.kernel.org To: Luben Tuikov Cc: linux-scsi > * SAM-3 specifies that a LUN is 64 bit. While there may not > be any devices which actually even come close to using this > huge space, it provides different _addressing__modes_. > > This very nicely fits LUN virtualization (iSCSI, LUN masking, etc), > and would allow one to do magic for storage devices (IP SANs, etc). > > A 64 bit LUN could be presented to userspace which may/can then > present a nice ``picture'' (GUI or what not) of the underlying > physical/virtual (depending on the SCSI port name/id) storage > network. > > (E.g. iSCSI communicates 64 bit LUNs only...) To me all of the proposed changes look good. The one above I'd be interested in particularly. It would help sorting out a lot of woes we had with writing a fibre-channel HBA driver. For fibre-channel LUNs and port IDs (WWPN) are 64-bit and depending on configuration, high values can be (and in our case are) common. Aron