If customers are using D1000 arrays on their systems, and try to add additional device entries to the /kernel/drv/sd.conf file, it is necessary to ensure that certain target numbers remain unused. Situations have arisen where people try to attach EMC arrays or other third-party hardware to Sun servers, and have been given specific targets to enter in sd.conf. In the case of Symmetrix arrays, up to 128 LUNs per target are possible, and are configured at the array level initially. If target 14 or 15 is attempted on systems that run D1000's, various types of mischief could result. The entries generally appear as follows (output has been truncated for current purposes):

name="sd" class="scsi" target=15 lun=0;

name="sd" class="scsi" target=15 lun=1;

name="sd" class="scsi" target=15 lun=2;

name="sd" class="scsi" target=15 lun=3;

name="sd" class="scsi" target=15 lun=4;

name="sd" class="scsi" target=15 lun=5;

One thing that may indicate a conflict is that the system will hang on boot. A boot -v or -rv will provide information about where the process is bogging down. Shutting the server down, removing the offending entries in the sd.conf file, and rebooting should fix this. One may find supporting documentation on page 4 of P/N 805-4866, the Sun StorEdge A1000/D1000 Product Note: "Caution: Do not assign SCSI ID numbers 14 or 15 to any device. Both SCSI ID 14 and 15 are reserved for the GEM chips (SCSI enclosure sensing chips) on the controller board."

This obviates the need for alternate SCSI targets to be assigned to the device that was originally intended for addition. Thus, reconfiguring the Symmetrix or other array/device is necessary, and new entries subsequently written to the sd.conf file.

• R.B. Khleif, Storage TSE (khleif@sun.com)