topic Odd disk slices - 11.23 on an rx7640 in Operating System - HP-UX

Odd disk slices - 11.23 on an rx7640

Patrick Wallek — Fri, 09 May 2014 19:00:50 GMT

A co-worker and I were assisting a customer in migrating an rx7640 running 11.23 with 5 vPars from one fibre switch to another. Unfortunately there was only a single fibre path, so we had to shut down, migrate to the new switch and get all vPars booted on the new hardware. That whole process went fine and we had no major issues.

The one odd thing we found was that on all of the vPars that booted from SAN, the boot LUNs are suddenly showing 7 slices on the boot disk rather than the normal 3.

For example:

From an ioscan on a vPar:

disk 101 1/0/8/1/0.210.5.239.0.0.1 sdisk CLAIMED DEVICE DGC CX3-40WDR5

/dev/dsk/c14t0d1 /dev/dsk/c14t0d1s4 /dev/rdsk/c14t0d1 /dev/rdsk/c14t0d1s4

/dev/dsk/c14t0d1s1 /dev/dsk/c14t0d1s5 /dev/rdsk/c14t0d1s1 /dev/rdsk/c14t0d1s5

/dev/dsk/c14t0d1s2 /dev/dsk/c14t0d1s6 /dev/rdsk/c14t0d1s2 /dev/rdsk/c14t0d1s6

/dev/dsk/c14t0d1s3 /dev/dsk/c14t0d1s7 /dev/rdsk/c14t0d1s3 /dev/rdsk/c14t0d1s7

However, when we had the server booted in nPar mode to determine the new hardware paths to boot the vPars from, the disk had the correct number of slices.

From an ioscan in nPar mode:

disk 579 1/0/8/1/0.210.5.239.0.0.1 sdisk CLAIMED DEVICE DGC CX3-40WDR5
/dev/dsk/c97t0d1 /dev/dsk/c97t0d1s3 /dev/rdsk/c97t0d1s2
/dev/dsk/c97t0d1s1 /dev/rdsk/c97t0d1 /dev/rdsk/c97t0d1s3
/dev/dsk/c97t0d1s2 /dev/rdsk/c97t0d1s1

The disk also showed the normal 3 slices BEFORE the move to the new fibre switch:

disk 1 1/0/8/1/0.20.25.239.0.0.1 sdisk CLAIMED DEVICE DGC CX3-40WDR5

/dev/dsk/c4t0d1 /dev/rdsk/c4t0d1
/dev/dsk/c4t0d1s1 /dev/rdsk/c4t0d1s1
/dev/dsk/c4t0d1s2 /dev/rdsk/c4t0d1s2
/dev/dsk/c4t0d1s3 /dev/rdsk/c4t0d1s3

The odd thing is that if you run an 'idisk -p' on the whole disk that is showing the 7 slices you only see:

# idisk -p /dev/rdsk/c14t0d1

idisk version: 1.32

EFI Primary Header:

Signature = EFI PART

Revision = 0x10000

HeaderSize = 0x5c

HeaderCRC32 = 0xb83d558f

MyLbaLo = 0x1

MyLbaHi = 0x0

AlternateLbaLo = 0x77fffff

AlternateLbaHi = 0x0

FirstUsableLbaLo = 0x22

FirstUsableLbaHi = 0x0

LastUsableLbaLo = 0x77fffdc

LastUsableLbaHi = 0x0

Disk GUID = 409b8e1a-990c-11de-8001-d6217b60e588

PartitionEntryLbaLo = 0x2

PartitionEntryLbaHi = 0x0

NumberOfPartitionEntries = 0xc

SizeOfPartitionEntry = 0x80

PartitionEntryArrayCRC32 = 0xbcfb13e4

Primary Partition Table (in 512 byte blocks):

Partition 1 (EFI):

Partition Type GUID = c12a7328-f81f-11d2-ba4b-00a0c93ec93b

Unique Partition GUID = 409b8f96-990c-11de-8002-d6217b60e588

Starting Lba Lo = 0x22

Starting Lba Hi = 0x0

Ending Lba Lo = 0xfa021

Ending Lba Hi = 0x0

Partition 2 (HP-UX):

Partition Type GUID = 75894c1e-3aeb-11d3-b7c1-7b03a0000000

Unique Partition GUID = 409b8fb4-990c-11de-8003-d6217b60e588

Starting Lba Lo = 0xfa022

Starting Lba Hi = 0x0

Ending Lba Lo = 0x7737821

Ending Lba Hi = 0x0

Partition 3 (HPSP):

Partition Type GUID = e2a1e728-32e3-11d6-a682-7b03a0000000

Unique Partition GUID = 409b8fc8-990c-11de-8004-d6217b60e588

Starting Lba Lo = 0x7737822

Starting Lba Hi = 0x0

Ending Lba Lo = 0x77ff821

Ending Lba Hi = 0x0

So 'idisk' is only showing 3 slices on the disk but ioscan is seeing 7 slices.

Booting from the disk works fine and VG00 is fine using s2.

I am VERY VERY confused here. Does anyone have ANY ideas?

Re: Odd disk slices - 11.23 on an rx7640

Patrick Wallek — Mon, 12 May 2014 15:35:40 GMT

To add to the oddness... The whole disk, and disk slices 1 - 3 are correct, but disk slices 4 - 7 are showing a size of '0 bytes'.

diskinfo /dev/rdsk/c14t0d1

SCSI describe of /dev/rdsk/c14t0d1:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 62914560 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s1

SCSI describe of /dev/rdsk/c14t0d1s1:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 512000 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s2

SCSI describe of /dev/rdsk/c14t0d1s2:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 61991936 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s3

SCSI describe of /dev/rdsk/c14t0d1s3:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 409600 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s4

SCSI describe of /dev/rdsk/c14t0d1s4:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 0 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s5

SCSI describe of /dev/rdsk/c14t0d1s5:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 0 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s6

SCSI describe of /dev/rdsk/c14t0d1s6:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 0 Kbytes

bytes per sector: 512

diskinfo /dev/rdsk/c14t0d1s7

SCSI describe of /dev/rdsk/c14t0d1s7:

vendor: DGC

product id: CX3-40WDR5

type: direct access

size: 0 Kbytes

bytes per sector: 512

Is this somehow related to HP-UX, the vPar or the storage?

Re: Odd disk slices - 11.23 on an rx7640

Matti_Kurkela — Tue, 20 May 2014 14:49:55 GMT

I think I saw this behavior once. Apparently the system is not actually detecting the number of slices on disk, but simply generating the device nodes for "enough" slices. The fact that slices 4-7 show zero size just indicates that they don't actually exist.

My memory is hazy, but... perhaps the system was in a LVM recovery mode or some other recovery mode when I saw this?

Apparently your nPar mode boot disk now has the correct FC device paths for vg00 in its LVM configuration, but the vPars might each need to have their vg00 re-imported while booting to LVM recovery mode.