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Disabling iSCSI Targets Can Cause The Host Initiator an Abnormally Long Time To List iSCSI Devices (Doc ID 1642603.1)

Last updated on MAY 17, 2018

Applies to:

Solaris Operating System - Version 10 10/09 U8 and later
Information in this document applies to any platform.

Symptoms

Running an explorer on a host with iSCSI LUNs takes a long time or will hang
or even running ls -l /dev/rdsk/* takes a very long time or hang.

Changes

There are a couple of ways the problem can be seen:

A) Disable an existing iSCSI target used as part of a zpool on the host and rebooting the host.

Example

To add a view, the following command is used in COMSTAR

# stmfadm add-view -h host-group-a -t targets-0 -n 1 6000AE40C5000000000046FC4FEA001C


Similarly to disallow host access, the following command can be used.

# stmfadm remove-view -h host-group-a -t targets-0 -n 1 6000AE40C5000000000046FC4FEA001C

Then

# reboot


On boot, run

# zpool status


The system will hang.
Ctrl-C not work.
kill will not work

Reset the initiator box and the system will experience problems will booting

NOTICE: iscsi discovery failure - SendTargets (xxx.xxx.xxx.xxx)
NOTICE: iscsi connection(6) unable to connect to target SENDTARGETS_DISCOVERY

repeats many time

Solution: make the target lun available:
# stmfadm add-view -h host-group-a -t targets-0 -n 1 6000AE40C5000000000046FC4FEA001C

The host is now able to boot.



B) Another way of achieving the same effect:

1. Creating iscsi targets and getting them discovered on the initiator host.

# mkfile 2m /export/home/hoge_X
# iscsitadm create target -b /export/home/hoge_X hogeX


2. Recognizing Solaris targets by SendTargets access.
After that, creating the device files under /dev/rdsk by running "devfsadm -C"

# iscsiadm add discovery-address XXX.XXX.XX.XX
# iscsiadm modify discovery -t enable
# devfsadm -C


3. Disable the discovery

# iscsiadm modify discovery -t disable

3. Then delete some of the iscsi targets using the command

# iscsitadm delete target -u 0 hogeX

4. Start a discovery of the iscsi targets.

# iscsiadm modify discovery -t enable

5. Start I/O on a target

# dd if=/dev/rdsk/c1t0d0s6 of=/dev/null


6. Bring down the link during i/o access
On the initiator side,

# ifconfig bge1 down



5. On the initiator side, run

# ls -l  /dev/*dsk/* "


The device links of the previous devices under the /dev/*dsk/* will cause the commands to hang.

Cause

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In this Document
Symptoms
Changes
Cause
Solution
References

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