XenServer MultiPath Info

Useful commands discovered and used along the way. 

Check iSCSI sessions

iscsiadm -m session

Ping storage from a particular NIC IP address

ping -I xenbr8 192.168.190.10

Note: You may need to use this command to figure out where to ping from
brctl show
Show info on virtual switches

Rescan iscsi sessions

iscsiadm -m session -r 1 --rescan

Show all records in discovery database and show the targets that
were discovered from each record:
./iscsiadm -m discovery -P 1

Display session statistics:
./iscsiadm -m session -r 1 --stats

Display running sessions:
./iscsiadm -m session -P 1

Restart iscsi service
service open-iscsi restart

Check iscsi service status
service open-iscsi status

To get information about the running sessions: including the session and
device state, session ids (sid) for session mode, and some of the
negotiated parameters, run:
iscsiadm -m session -P 2

To get a Host view of the session there is the host mode.
iscsiadm -m host

Log into iSCSI targets
iscsiadm -m node --login

To log into an individual iSCSI target use:
iscsiadm -m node -l -T iqn.2001-05.com.equallogic:83bcb3401-16e0002fd0a46f3d-rhel5-test -p 172.23.10.240:3260





MultiPath troubleshooting

You can view multi-path logs in /var/log/SMlog

Commands to display paths in use and status

mpathutil status

or

multipath -ll


To increase the verbosity for multipathing logs

1. Using a program like WinSCP or the CLI method of your choice, on each host in the pool, open
the /etc/multipath.conf file.

2. Find the section for your storage device, in the defaults section, add the keyword “verbosity” and
increase the verbosity to the maximum (6):

defaults

{

user_friendly_names no

pg_prio_calc “avg”

verbosity 6

}

Note: Valid values for the verbosity keyword are 0 to 6, where 6 is the maximum verbosity.
By default, without specifying a keyword, verbosity is set to 2.


3. Save the multipath.conf file and close it. Prio errors will begin to appear in the syslog.

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