1

I have the following boot-device:

/pci@400/pci@1/pci@0/pci@4/scsi@0/disk@w32a6b2f6484021d2,0:a

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?

2

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.

Followup:

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
/pci@400/pci@2/pci@0/pci@e/scsi@0

FCode Version 1.00.54, MPT Version 2.00, Firmware Version 5.00.17.00

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

/pci@400/pci@1/pci@0/pci@b/pci@0/usb@0,2/hub@2/hub@3/storage@2
  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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