How to Unconfigure a Single Lun from a Target which has multiple Luns

Asset ID:	1-71-1018716.1
Update Date:	2011-06-08
Keywords:

Solution Type Technical Instruction Sure

Solution 1018716.1 : How to Unconfigure a Single Lun from a Target which has multiple Luns

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Related Categories


GCS>Sun Microsystems>Storage Software>Sun Storage SAN Software
 GCS>Sun Microsystems>Storage - Disk>Modular Disk - Other
 GCS>Sun Microsystems>Storage - Disk>Modular Disk - 3xxx Arrays
 GCS>Sun Microsystems>Storage - Disk>Modular Disk - 6xxx Arrays
 GCS>Sun Microsystems>Storage - Disk>Datacenter Disk

PreviouslyPublishedAs
230430

Description
In today's san environment, where scheduling a reboot is highly difficult, you would have come across situations where you need to unconfigure a single Lun out of the many that are presented to the same target without reboot.

Note : The following procedure relies on the unmaping/removal of the LUN from the storage target and should not be confused with host based LUN masking. Host based LUN masking is the host 'masking' out selected LUNS from those being presented by a target (rather than the host configuring/using all the LUNs that are being presented). If host based LUN masking is required, Solaris[TM] 10 update 3 introduced this functionality. For more information on host based LUN masking see fp man page for details. 'man -s 7D fp'

A. This procedure is valid only for the Sun Leadville Stack using the cfgadm commands with the minimum revision of the following patches :

142088 for Sol10

113044 for Sol9

111846 for Sol8

B. On Solaris 10 the hardware options with cfgadm commands have changed.

See cfgadm_fp man page for details.

C. Procedure applies to Lun unmapped from the array side , and not for host based lun masking (on presented luns) which was introduced in S10u3 and later.

-As of today there is no option with the cfgadm cmd to unconfigure a Single Lun.

The only option available is to unconfigure the complete target device which is not helpful in situations where we have 100's of luns presented on the same target and you need to get rid of a few.

Now with the last solaris update, the only way to achieve this is to get the luns into a unusable state and then unconfigure it.

How to get a Lun to show up as unusable

A. If possible Change the permission of the lun on the Array to None instead of Read Only Or Read Write

B. UnMap the Luns from that Port ( target device) on the array.

Below are the steps that need to be followed. The array used in the below example is a Sun StorEdge[TM] T3+

Steps to Follow
How to unconfigure a single Lun from a target which has multiple Luns:

A. Cfgadm shows the 3 luns presented on c4 and c5

# cfgadm -al -o show_FCP_dev

Ap_Id Type Receptacle Occupant Condition

c3 fc connected unconfigured unknown

c4 fc-fabric connected configured unknown

c4::50020f23000096b9,0 disk connected configured unknown

c4::50020f23000096b9,1 disk connected configured unknown

c4::50020f23000096b9,2 disk connected configured unknown

c5 fc-fabric connected configured unknown

c5::50020f2300008f6b,0 disk connected configured unknown

c5::50020f2300008f6b,1 disk connected configured unknown

c5::50020f2300008f6b,2 disk connected configured unknown

On solaris 10 the command to use will be

# cfgadm -al -o show_SCSI_LUN

B. On the Array ( T3+) we have 3 volslices with readwrite permission

purple2:/:<1>volslice list

Slice Slice Num Start Blk Size Blks Capacity Volume

sl1 0 0 20971520 10.000 GB v1

test 1 20971520 20971520 10.000 GB v1

s2 2 41943040 664797184 317.000 GB v1

- - 706740224 1637376 799.500 MB v1

purple2:/:<3>lun perm list

lun slice WWN Group Name Group Perm WWN Perm Effective Perm

--------------------------------------------------------------------------------------------------------------------------

0 0 default -- -- rw rw

1 1 default -- -- rw rw

2 2 default -- -- rw rw

C. Change the permission on Lun 2 from rw to none

purple2:/:<5>lun default lun 2 none

purple2:/:<6>lun perm list

lun slice WWN Group Name Group Perm WWN Perm Effective Perm

--------------------------------------------------------------------------------------------------------------------------

0 0 default -- -- rw rw

1 1 default -- -- rw rw

2 2 default -- -- none none

D. Now cfgadm shows Lun 2 as unusable

# cfgadm -al -o show_FCP_dev

Ap_Id Type Receptacle Occupant Condition

c3 fc connected unconfigured unknown

c4 fc-fabric connected configured unknown

c4::50020f23000096b9,0 disk connected configured unknown

c4::50020f23000096b9,1 disk connected configured unknown

c4::50020f23000096b9,2 disk connected configured unusable

c5 fc-fabric connected configured unknown

c5::50020f2300008f6b,0 disk connected configured unknown

c5::50020f2300008f6b,1 disk connected configured unknown

c5::50020f2300008f6b,2 disk connected configured unusable

E. We have achieved our goal to get the Lun to show up as unusable , now use the following command to unconfigure the Lun

# cfgadm -c unconfigure -o unusable_FCP_dev c4::50020f23000096b9

On Solaris 10 the command to use will be

# cfgadm -c unconfigure -o unusable_SCSI_LUN c4::50020f23000096b9

# cfgadm -al -o show_FCP_dev

Ap_Id Type Receptacle Occupant Condition

c3 fc connected unconfigured unknown

c4 fc-fabric connected configured unknown

c4::50020f23000096b9,0 disk connected configured unknown

c4::50020f23000096b9,1 disk connected configured unknown

c5 fc-fabric connected configured unknown

c5::50020f2300008f6b,0 disk connected configured unknown

c5::50020f2300008f6b,1 disk connected configured unknown

c5::50020f2300008f6b,2 disk connected configured unusable

F. Run the same command on the other Path ( c5 )

# cfgadm -c unconfigure -o unusable_FCP_dev c5::50020f2300008f6b

On Solaris 10 the command to use will be

# cfgadm -c unconfigure -o unusable_SCSI_LUN c5::50020f2300008f6b

# cfgadm -al -o show_FCP_dev

Ap_Id Type Receptacle Occupant Condition

c3 fc connected unconfigured unknown

c4 fc-fabric connected configured unknown

c4::50020f23000096b9,0 disk connected configured unknown

c4::50020f23000096b9,1 disk connected configured unknown

c5 fc-fabric connected configured unknown

c5::50020f2300008f6b,0 disk connected configured unknown

c5::50020f2300008f6b,1 disk connected configured unknow

You have sucessfully unconfigured Lun 2 from a Target that has other luns assigned to it without a Reboot

Product
Sun StorageTek T3 Array
Sun StorageTek T3+ Array
Sun StorageTek 6120/6320 Controller Firmware 3.2
Sun StorageTek 3511 SATA Array
Sun StorageTek 3510 FC Array
Sun StorageTek 6320 System
Sun StorageTek 6120 Array

Internal Comments
The following CR are related to same issue, describing the difficulties to remove LUN in a SAN configuration.

CR: 6444373, 2139937, 2139938, 2139937, 2139865 cfgadm cann't remove
unusable lun, when other luns are being used

CR: 6482253 cfgadm fails to unconfigure unusable luns on a
controller when the devices are under VxVM control

CR: 6463935 cfgadm failed to unconfigure luns if remain
paths from same port with MPxIO

All these CR will be fixed in Solaris11
(solaris-nevada)and seems to be backported in Solaris 10-u3,
Solaris 9 and Solaris 8 with the mentionned patches (
look at README)

cfgadm, unconfigure, unusable, T3, T3+, 6120, 6320, Hitachi, unusable_FCP_dev, unusable_SCSI_LUN
Previously Published As
82516

Change History
Date: 2007-12-11
User Name: 95826
Action: Approved
Comment: - verified metadata
Date: 2009-12-22
User Name: sue.copeland@sun.com
Action: Currency & Update

- changed review date to 2008-12-10
- checked for TM - none added
- checked audience : contract
Publishing
Version: 16
Date: 2007-12-10
User Name: 95826
Action: Accept
Comment:
Version: 0

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