Oracle VM: iscsi,multipath and ocfs2 connections/reboots using Dell Equallogic San (Doc ID 1273899.1)

Last updated on APRIL 24, 2017

Applies to:

Oracle VM - Version 2.2 and later
Information in this document applies to any platform.
***Checked for relevance on 24-Jul-2012***
***Checked for relevance on DD-Mon-YYYY***

Symptoms

When having two network cards connected to the Dell Equallogic san this creates
the multiple logins needed for Linux device mapper to work as you have a connection for each GbE interface  connected to the array.

What is seen during testing of a failed network card that the multipathing is not failing over and ocfs2 is evicting itself as designed.

With both network cards up (eth0, eth6):

# multipath -ll
36090a048f01dc27bf0b8a4000000d09d dm-1 EQLOGIC,100E-00
[size=3.0K][features=0][hwhandler=0][ro]
\_ round-robin 0 [prio=0][active]
\_ 11:0:0:0 sdb 8:16 [active][ready]
\_ 12:0:0:0 sdc 8:32 [active][ready]


Disks are from iscsi:

# iscsiadm -m session -P 3

**********
Interface:
**********
Iface Name: ieth0
Iface Transport: tcp
Iface Initiatorname: iqn.1994-05.com.redhat:9b9d95fbe16
..
Iface Netdev: xenbr0
SID: 9
iSCSI Connection State: LOGGED IN
iSCSI Session State: LOGGED_IN
Internal iscsid Session State: NO CHANGE
************************
Negotiated iSCSI params:
************************
HeaderDigest: None
DataDigest: None
MaxRecvDataSegmentLength: 262144
MaxXmitDataSegmentLength: 65536
FirstBurstLength: 65536
MaxBurstLength: 262144
ImmediateData: Yes
InitialR2T: No
MaxOutstandingR2T: 1
************************
Attached SCSI devices:
************************
Host Number: 11 State: running
scsi11 Channel 00 Id 0 Lun: 0
Attached scsi disk sdb State: running   <----


===================


**********
Interface:
**********
Iface Name: ieth6
Iface Transport: tcp
Iface Initiatorname: iqn.1994-05.com.redhat:9b9d95fbe16
..
Iface Netdev: xenbr6
SID: 10
iSCSI Connection State: LOGGED IN
iSCSI Session State: LOGGED_IN
Internal iscsid Session State: NO CHANGE
************************
Negotiated iSCSI params:
************************
HeaderDigest: None
DataDigest: None
MaxRecvDataSegmentLength: 262144
MaxXmitDataSegmentLength: 65536
FirstBurstLength: 65536
MaxBurstLength: 262144
ImmediateData: Yes
InitialR2T: No
MaxOutstandingR2T: 1
************************
Attached SCSI devices:
************************
Host Number: 12 State: running    <-- SCSI Error Handler is running
scsi12 Channel 00 Id 0 Lun: 0
Attached scsi disk sdc State: running  <---


The /etc/iscsi/iscsid.conf output:

node.startup = automatic
node.session.auth.authmethod = CHAP
node.session.auth.username = <user>
node.session.auth.password = <pass>
node.session.timeo.replacement_timeout = 120
node.conn[0].timeo.login_timeout = 15
node.conn[0].timeo.logout_timeout = 15
node.conn[0].timeo.noop_out_interval = 5
node.conn[0].timeo.noop_out_timeout = 5
node.session.err_timeo.abort_timeout = 15
node.session.err_timeo.lu_reset_timeout = 20
node.session.initial_login_retry_max = 8
node.session.cmds_max = 128
node.session.queue_depth = 32
node.session.xmit_thread_priority = -20
node.session.iscsi.InitialR2T = No
node.session.iscsi.ImmediateData = Yes
node.session.iscsi.FirstBurstLength = 262144
node.session.iscsi.MaxBurstLength = 16776192
node.conn[0].iscsi.MaxRecvDataSegmentLength = 262144
discovery.sendtargets.iscsi.MaxRecvDataSegmentLength = 32768
node.conn[0].iscsi.HeaderDigest = None
node.session.iscsi.FastAbort = Yes


The ocfs2 output:

#/etc/init.d/o2cb status
Driver for "configfs": Loaded
Filesystem "configfs": Mounted
Driver for "ocfs2_dlmfs": Loaded
Filesystem "ocfs2_dlmfs": Mounted
Checking O2CB cluster ocfs2: Online
Heartbeat dead threshold = 31
Network idle timeout: 30000
Network keepalive delay: 2000
Network reconnect delay: 2000
Checking O2CB heartbeat: Active
#


Test fail over by ifdown eth6, and tailing the /var/log/messages file:

Ping fails:

Dec 14 05:21:26 host kernel: connection12:0: ping timeout of 5 secs expired, recv timeout 5, last rx 727894019, last ping 727895269, now 727896519
Dec 14 05:21:26 host kernel: connection12:0: detected conn error (1011)

Dec 14 05:21:27 host iscsid: Kernel reported iSCSI connection 12:0 error (1011) state (3)
Dec 14 05:21:54 host multipathd: sdc: readsector0 checker reports path is down
Dec 14 05:21:54 host multipathd: checker failed path 8:32 in map 36090a048f01dc27bf0b8a4000000d09d

At this point the VM server restarts:

Dec 14 05:58:25 host syslogd 1.4.1: restart.
Dec 14 05:58:25 host kernel: klogd 1.4.1, log source = /proc/kmsg started.
Dec 14 05:59:13 host kernel: Linux version 2.6.18-128.2.1.4.27.el5xen (mockbuild@ca-build9.us.oracle.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)) #1 SMP Sat Jul 24 02:16:40 EDT 2010

Cause

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