The problem is not related to network, it's related to the type of VM you selected.
Below exception can indicate that you try to use template which is fully PV template and booting system which is not PV. So I would say:
* system you trying to install on XS is not supported
* you picked up wrong template
* you booting off the wrong ISO

What template do you select while you create VM in CS?
What system you trying to install?

2013-04-17 10:51:04,213 WARN http://xen.resource.CitrixResourceBase (DirectAgent-380:null) Task failed! Task record: uuid: 5bee47aa-1c53-0efe-d352-cafeef3466b2
errorInfo: Traceback (most recent call last):, File "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0], bootfsoptions), IOError: [Errno 95] Operation not supported,
2013-04-17 10:51:04,227 WARN http://xen.resource.CitrixResourceBase (DirectAgent-380:null) Unable to start VM(i-3-19-VM) on host(aee0fd17-8d31-464f-a885-4528c8f5d76c) due to Task failed! Task record: uuid: 5bee47aa-1c53-0efe-d352-cafeef3466b2
errorInfo: Traceback (most recent call last):, File "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0], bootfsoptions), IOError: [Errno 95] Operation not supported,

Thanks

I re-created the Advanced zone fixed the issue. Now the issue is I'm not able to access the guest VM from outside network.

Setup Background

I created Advanced zone and created isolated network from new Account I created . Network offerings selected is Default Isolated Network offerings with Source NAT service. Now I'm able to create Instances with defined VLAN.But not able to ping or ssh from outside

I tried creating NW offerings without Source NAT and Static NAT, but not displaying the new offerings in the drop down list

> But not able to ping or ssh from outside
Are you trying to ping it from the same VLAN? you would need to be in the same VLAN cloud stack picked up to create your network.
You can also try ping public IP of VR for this network.

Radek.

Are you trying to ping it from the same VLAN?

yes I can ping from same VLAN

you would need to be in the same VLAN cloud stack picked up to create your network.

My MAN NW and guest VLAN is different not the same

You can also try ping public IP of VR for this network.

Not able to ping public IP of VR from MAN NW ans well as from outside

I have another question as well

If I want to use external load balancer F5 , is it mandate to use an external firewall rather than using VR as Firewall service?

Anoop

So many question in this thread...

"Not able to ping public IP of VR from MAN NW ans well as from outside"

Check the configuration of the public IP assigned to the VR. You will likely need to modify the firewall to allow ICMP traffic of type -1 from 0.0.0.0/0 (This allows from anywhere)

"If I want to use external load balancer F5 , is it mandate to use an external firewall rather than using VR as Firewall service?"

No. Several of our clients have used an external device, for the load balancing, and used the VR for Static/Source NAT. The "public" IPs used by the load balancer don't really get or need a firewall, since only the appropriate ports are open anyway. The VR's firewall is configured via the CCP UI and controls the "public" IPs used for Static NAT and port forwarding.

Hope this helps.

--Mike