henkel%nepjt@ncsuvx.ncsu.edu (Chuck Henkel) (06/25/91)
A connection address for a SCSI device has the form AA-BB-CC-DD where DD, according to info, is the SCSI ID and logical unit number [LUN], in that order. So what is the LUN? Is it always 0? The SCSI ID is set on the device itself; is the LUN also? -- | Chuck Henkel | There are currently 111 operating | | Department of Nuclear Engineering | nuclear power plants in the US, | | N.C. State University | generating nearly 100,000 Megawatts | | henkel%nepjt@ncsuvx.ncsu.edu | of electricity. |
johnson@aixwiz.austin.ibm.com (Fred L. Johnson) (06/25/91)
In article <HENKEL%NEPJT.91Jun24132655@ners6k2.ncsuvx.ncsu.edu>, henkel%nepjt@ncsuvx.ncsu.edu (Chuck Henkel) writes: > A connection address for a SCSI device has the form AA-BB-CC-DD where > DD, according to info, is the SCSI ID and logical unit number [LUN], > in that order. > > So what is the LUN? Is it always 0? The SCSI ID is set on the device > itself; is the LUN also? The logical unit number is just a way to subdivide a SCSI ID so that several devices in a single logical unit can be addressed by the same SCSI ID but also can be addressed individually via the LUN. It increases greatly the number of devices that can be attached to a single SCSI bus. Currently all of the supported devices have a single LUN which is set to zero. I know of some OEMs that are working on multiple LUN devices for the RISC System/6000 and I would imagine that we would release some of our own. The software support for multiple LUNs is already in place. - Fred My remarks and opinions are mine alone... ____________________________________________________________________________ | | | | Fred L. Johnson | Internet: johnson@aixwiz.austin.ibm.com | | IBM Personal Systems Programming | inet: johnson@tanstaafl.austin.ibm.com | | AIX BOS Field Quality | vnet: FJOHNSON at AUSVMQ | | 11400 Burnet Road, 994/3401 | phone: (512) 823-4706 | | Austin, TX 78758-3493 | tie line: 793-4706 | |__________________________________|_________________________________________|