Oracle ZFS Storage Appliance: ISCSI LUNs Allocated to Linux Clients Fail Discovery with "Logical Unit Not Accessible" Errors

Asset ID:	1-72-1937173.1
Update Date:	2014-11-18
Keywords:

Solution Type Problem Resolution Sure

Solution 1937173.1 : Oracle ZFS Storage Appliance: ISCSI LUNs Allocated to Linux Clients Fail Discovery with "Logical Unit Not Accessible" Errors

Applies to:

Sun ZFS Storage 7320 - Version All Versions and later
Sun Storage 7210 Unified Storage System - Version All Versions and later
Sun ZFS Storage 7420 - Version All Versions and later
Oracle ZFS Storage ZS3-2 - Version All Versions and later
Oracle ZFS Storage ZS3-4 - Version All Versions and later
7000 Appliance OS (Fishworks)

Symptoms

Multiple iSCSI LUNs are created and managed from a Project on an Oracle ZFS Appliance.

The LUNs are assigned to a unique target group and initiator group, such that they are exclusively available to a Linux client.

When the Linux client is rebooted, enumeration of any LUN after LUN 0 fails. The log files on the client will report the following:

------------------
Attached 34:0:0:0: attached scsi generic sg5
kernel: scsi 34:0:0:1: Done Success
Host Byte=DID_OK Driver=Driver_ok
CDB Inquiry: 12 00 00 00 2400
Sense Key: Not Ready
Add. Sense: Logical Unit Not accessible, Target port in unavailable state
34:0:0:0: Unexpected response from lun 1 while scanning. scan aborted.
------------------

This error indicates

The Linux client successfully issued an INQUIRY to LUN 1 (34:0:0:1)
LUN 1 responded with a sense key of 'Not Ready'
The ASC/ASCQ codes returned were asc,ascq=04h,0Ch
These translate to Logical Unit Not accessible, Target port in unavailable state
All subsequent device enumeration terminates at this point.

Once LUN 0 is enumerated successfully, the Linux command sg_luns is run against LUN 0 to gather inquiry information about what else is being presented from the appliance.

The output below shows that 5 LUNs (0, 1, 2, 3, 4, and 5) were presented from the ZFS appliance to the Linux client.

#sg_luns /dev/sdX
Lun list length = 40
Report luns [select_report=0]:
000000000000000
000100000000000
000200000000000
000300000000000
000500000000000

Cause

The problem is with the iSCSI configuration on the ZFS appliance.

For unknown reasons, several, previously deleted iSCSI LUNs are still being presented to the client.

The LUNs do not appear in output from the CLI, but they do appear in output from the shell.

ZFS-NODE1:> shares Linux-Proj> list
LUNs:
NAME              VOLSIZE GUID
lun20             20G     600144F0C0D6CC01000054453D2F0003
lun0              5G      600144F0C0D6CC01000054453C430001
lun40             40G     600144F0C53A5DCE000054453EFF0002

Shell output.

# oracle only restrcited-command
LU Name: 600144F0C0D6CC01000054453C430001
LU Name: 600144F0C0D6CC01000054453CFB0002
LU Name: 600144F0C0D6CC01000054453D2F0003
LU Name: 600144F0C53A5DCE000054453EF20001
LU Name: 600144F0C53A5DCE000054453EFF0002

Solution

The problem is resolved by opening an SR with Oracle Support to manually remove the iSCSI LUNs from the configuration.

Once the iSCSI LUNs are removed, the Linux client should be rebooted.

            "Warning : The following command(s)/instruction(s) may result in changes to appliance settings/configuration, and could
                          therefore result in serious damage if not fully understood and implemented correctly. These steps must be
                          carried out only by a highly experienced Oracle TSC or Field Support engineer, trained to work at the Solaris
                          Shell on the ZFS Storage Appliance. If you are at all unsure whether to proceed, please stop and consult your
                          manager or supervisor immediately.".

From the shell, list out the iSCSI LUNs with stmfadm. You can then identify and delete phantom LUNs.

ZFS-NODE1# stmfadm list-lu
   LU Name: 600144F0C0D6CC01000054453C430001
   LU Name: 600144F0C0D6CC01000054453CFB0002
   LU Name: 600144F0C0D6CC01000054453D2F0003
   LU Name: 600144F0C53A5DCE000054453EF20001
   LU Name: 600144F0C53A5DCE000054453EFF0002

ZFS-NODE1# stmfadm delete-lu 600144F0C0D6CC01000054453CFB0002
ZFS-NODE1# stmfadm delete-lu 600144F0C53A5DCE000054453EF20001

ZFS-NODE1# stmfadm list-lu
   LU Name: 600144F0C0D6CC01000054453C430001
   LU Name: 600144F0C0D6CC01000054453D2F0003
   LU Name: 600144F0C53A5DCE000054453EFF0002

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