Testing HA before going in to production

[dsimmons@engsin.com]

I would like to fail a node to see if me HA is working. How can I do this short of powering 1 of the starwind servers off? would stopping the service be sufficient?

[anton (staff)]

Stopping StarWind service, powering off machine, taking network cable away from the switch, throwing server away from the 17th floor etc etc etc.

I would like to fail a node to see if me HA is working. How can I do this short of powering 1 of the starwind servers off? would stopping the service be sufficient?

[dsimmons@engsin.com]

Question, how does a server know to connect over to the failover volume on the other san? I'm not using DNS in the subnet that my SAN volumes are presented on. i am using xen server to host my VM's. I created a storage pool and pointed it to my HA target. I then created a vm that uses some space in that storage as the boot lun. Do I have to set up the HA in Xen? Thanks.

[anton (staff)]

When you'll walk down the HA configuration wizard you'd be prompted to point second HA volume.

Question, how does a server know to connect over to the failover volume on the other san? I'm not using DNS in the subnet that my SAN volumes are presented on. i am using xen server to host my VM's. I created a storage pool and pointed it to my HA target. I then created a vm that uses some space in that storage as the boot lun. Do I have to set up the HA in Xen? Thanks.

[dsimmons@engsin.com]

Are you refering to the HA wizard in xen (which I haven't found yet) or when I made the target in starwind? If you mean in the starwind interface, how does that let xen server know that there is a second target? Sorry for all the questions.

[anton (staff)]

StarWind HA of course!

Are you refering to the HA wizard in xen (which I haven't found yet) or when I made the target in starwind? If you mean in the starwind interface, how does that let xen server know that there is a second target? Sorry for all the questions.

[dsimmons@engsin.com]

This must be the limitation of my knowledge. Maybe you can point out why I am confused
If I have a target that is set up as HA, and 1 of the starwind servers goes down, how does XEN know to find the target? I think when I set up targets in xen, it points to 1 server and sees the targets from the starwind server. Are you saying that there is something about how iscsi targets are presented that an initiator knows to point to the failover server automatically?

[Constantin (staff)]

Manual to connect HA to XEN.
Configure XenServer Host for Multipath

1. From XenCenter GUI configure XenServer Pool and add Servers.

2. Edit the ‘/etc/multipath-enabled.conf’ file on each XenServer host
Important Note: ‘/etc/mutipath.conf’ is a soft link that points to ‘/etc/multipath-enabled.conf’
Find the first defaults section in the file. It will be the uncommented defaults section at the beginning of the file. Within this section, copy the “polling_interval” line from the second defaults section which is commented out with hash (#) symbols at the beginning of the line and then remove the #.
For example, when you are finished, it will look like this: defaults {
user_friendly_names no polling_interval 10
}

Enable the Multi-pathing support on each XenServer host from the XenCenter GUI:

3. Put the XenServer host in maintenance mode
4. Click on general > properties > multi-pathing
5. Select “enable multi-pathing”
6. Exit maintenance mode

Then to continue the prep I do the following (and this is the key, logging into the targets from the command line): Up to step 7 is critical after that is more about making sure you reconnect on reboot

Configure the Software iSCSI Initiator to Login to the StarWind`s Targets
1. From the XenCenter GUI, click on the XenServer Host name then click on the console tab and login as root.

2. Edit ‘/etc/iscsi/iscsid.conf’ (Note: for XenServer 5.5 Edit ‘/etc/iscsi/iscsid-mpath.conf’) file as follows:
In the iSCSI settings section, uncomment the following line by removing the ‘#’: node.session.iscsi.ImmediateData = No
In the iSCSI settings section, comment out the following line by adding a ‘#’ at the beginning: #node.session.iscsi.ImmediateData = Yes

3. Edit ‘/etc/iscsi/initiatorname.iscsi’ file and add the following arguments on separate lines as follows: InitiatorName= <iqn name of XenServer Host>
For example: InitiatorName=iqn.2007-11.example.com:1c677f65
This iqn name can be found in the XenCenter Console General tab.
InitiatorAlias= <XenServer Host Name> – this is the network name of your XenServer Host For example:
InitiatorAlias=xenserver-2

4. Start the iscsi daemon by typing the following command on the XenServer console:
service open-iscsi restart

5. To get open-iscsi to automatically start at run time, enter:
chkconfig --level 3 open-iscsi on

6. Discover targets by entering the following command for each target. Repeat this step for every Storage Server target that will serve storage to the XenServer host pool:
iscsiadm –m discovery –t sendtargets –p <ip address of iscsi target>

7. Login to targets by entering:
iscsiadm –m node –L all

8. Automate target logins for future system startups by entering the following for each target.
iscsiadm -m node –T <targetname> -p <ip address of iscsi target>:<listening \
port> --op update -n node.conn[0].startup -v automatic
For example:
/etc/iscsiadm -m node –T iqn.2000-08.com.starwind:titan-1 -p 172.168.8.80:3260 \ --op update –n node.conn[0].startup -v automatic

9. Edit ‘/etc/rc.d/rc.local’ and add the following lines at the end of the file: sleep 30
iscsiadm --mode node --loginall=all

10. Start the iscsi daemon by typing the following command on the XenServer console:
service open-iscsi restart

11. Repeat the above steps for every XenServer Host in the Pool.
This manual can be used for Xen 5.5 only!

[caleb72]

Has this been tested or are there any testing being done with XenServer 5.6?

[anton (staff)]

Yes.

P.S. We're waiting for Xen certification at this moment BTW.

Has this been tested or are there any testing being done with XenServer 5.6?

[xonus]

Sorry for resurrecting an old thread. But how is the certification for 5.6 coming along? Will the procedure above work for XenServer 5.6 as well?

[anton (staff)]

We're Xen certified ages ago...

http://hcl.xensource.com/BrowsableStorageList.aspx

ESX/ESXi certification is under way.

Sorry for resurrecting an old thread. But how is the certification for 5.6 coming along? Will the procedure above work for XenServer 5.6 as well?