I have the following boot-device:


And I would like to understand the syntax. What I know is:

  • /pci@400/pci@1/pci@0/pci@4/scsi@0: This is the name of the controller shown by probe-scsi-all.
  • /disk: It is obvious.
  • @w3: I do not know.
  • 2a6b2f6484021d2 is the WWID of the RAID volume as shown by show-volumes without the leading zero.
  • ,0:a: I guess this is the partition.

What is @w3 and how to get it from the OBP?


The disk id breakdown is actually slightly wrong:

  • ...
  • /disk is obvious
  • @ separates the device address (.../disk from the device identifier)
  • w for this disk device type indicates the device identifier is a WWN
  • 32a6b2f6484021d2 is the full WWN of the disk device
  • ,0 is the LUN number.
  • :a is the partition.

The full WWN is 32... - however, if this is different than what show-volumes is showing you, then I assume this is one path of a multi-path connection to the disk (for example, a storage array with multiple fibre connections to the same SAN could present the same disk with different WWNs on each storage array SAN connection). The show-volumes output shows the volume WWN, as opposed to the WWN of the path to get to that volume.


From the Oracle documentation, it appears that this WWN value appears in the output from probe-scsi-all. Their example is:

ok probe-scsi-all

FCode Version 1.00.54, MPT Version 2.00, Firmware Version

Target a 
  Unit 0   Removable Read Only device   TEAC    DV-W28SS-R      1.0C                    
  SATA device  PhyNum 3 
Target b 
GB  Unit 0   Disk   SEAGATE  ST914603SSUN146G 0868    286739329 Blocks, 146 
  SASDeviceName 5000c50016f75e4f  SASAddress 5000c50016f75e4d  PhyNum 1 
Target 389 Volume 0 
  Unit 0   Disk   LSI      Logical Volume   3000    583983104 Blocks, 298 GB
  VolumeDeviceName 33b2999bca4dc677  VolumeWWID 03b2999bca4dc677

  Unit 0   Removable Read Only device    AMI     Virtual CDROM   1.00

Notice the VolumeDeviceName 33b2999bca4dc677 VolumeWWID 03b2999bca4dc677 in Target 389.

  • Target 389 is the same target number as in show-volumes
  • VolumeWWID is the same WWID as in show-volumes
  • VolumeDeviceName is the WWN that you need to use to reference the volume.
| improve this answer | |
  • Which command outputs the 3... WWN? – ceving Sep 14 '16 at 13:12
  • unfortunately, it's been long enough since I used SPARC that I don't remember exactly. It should show up in the output of probe-scsi-all, or you can do something like show-devs to find all the devices, then for each scsi device, run the sequence select /pci@400/pci@1/pci@0/pci@4/scsi@0 followed by show-children followed by unselect-dev – J Earls Sep 14 '16 at 13:47
  • show-volumes shows WWNs. And those WWNs start with a 0 instead 3. I do not think, that the OBP knows anything about multi-path, which is an OS feature only visible to format. Nevertheless I have no multi-path, because it is just a RAID controller without multi-path. So the question is still open: where does the 3 come from? – ceving Sep 14 '16 at 14:32
  • what type of server? – J Earls Sep 14 '16 at 14:42
  • T4-1 with LSI RAID controller (SAS2008) – ceving Sep 14 '16 at 14:45

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