The Sun Enterprise Network Array is a desktop or rack mountable fibre channel (FCAL) disk array. It offers dual loops to dual ported fibre channel drives which may be 18GB, 36GB or 72GB in size. The array is a pretty inexpensive way to provide shared storage to multiple hosts for clustering. Sun servers dual attached to the array can take advantage of the multiple paths with VXVM so that the disk would remain available if one of the HBA's failed.

The A5000 supports 14 disks and the A5200 supports 22 disks. The disks are hot plugged into the front and back of the array and are refered to by slot# and front or rear. For example 5r would be the disk in rear slot number 5.

Sun provides a tool for managing the array called luxadm. The array status can be displayed and maintenance can be performed with luxadm.

The scsi ID's of the disks in the 5200 are determined by the box ID. For example if the box ID = 0 then the front drives are targets 0-10 and the rear drives are targets 16-26. If multiple 5200's are in 1 loop they must have unique box ID's. The previous statements only holds true if the host attached to the 5200 has a fully supported Sun HBA. The Sun supported HBA will recognize the 5200 disks and the enclosure and the host will create the es (Enclosure Services) devices and load the ses kernel module. The luxadm command uses the es devices to manage the enclosure. If you use an unsupported HBA you will not be able to use luxadm to manage the 5200 and you will need to configure bindings for each disk such that you know that target 0 is front slot 0 etc. This can be done by physically looking at the disks and noting the wwn printed on the disk handle and creating bindings using those WWN's. The additional management functions that could have been accomplished via luxadm will need to be done via the control panel. Virtually any HBA capable of loop mode can be used.

The following steps could be used to replace a disk in an A5200:

• luxadm probe - This will show the names of any enclosures seen by the server.

• luxadm display enclosure_name (enclosure_name determined in the previous step.

• luxadm remove_device enclosure,r5 - This command tells luxadm that you want to remove the disk in rear slot number 5. When the loop is ready luxadm will prompt the user to remove the device and THEN press enter. It is important to complete the steps in order.

• When the remove_device is complete the replacement disk is installed using "luxadm insert_device enclosure,r5" then following the prompts.

• If the disks are under vxvm control run "vxdctl enable" then vxdiskadm step 5 to complete the disk replacement.

  For additional information see the handbook at sunsolve.sun.com.