I am planning to start POC for vSRM using ESX3.5 U2. I have done demo and it went through but could not show all the functionality. Currently for POC purpose I need to design VLAN.
My question what kind of approach should I take for VLAN. Shall I use "streached VLAN's" as few/NetApp says or shall I re-ip those machine?
If someone can point me to understand from pros/cons as well as "How To" that would be great help.
If you want to keep it simple in terms of failover I would always prefer stretched vlan's. Especially dependency wise re-ip'ing can be a huge problem. (hardcoded ip's within apps / databases etc)
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Thanks, I am trying to find out detail understanding of stretched VLAN. My N/W managment team little hesitance to make any N/W changes and I need to sit with them and explain all 16 yard to them
we had a chat about networking here: http://communities.vmware.com/message/1113568#1113568 a while ago take a look.
One thing to think about is that most people I work with have a network strategy for DR that involves re-ip of the OS's. Usually when you dig a little deeper you find this strategy has not been reviewed for a looooooong time. Your network failover policy should and usually does go way beyond a VMWare concern as it will effect all platforms involved in failover.
From the x86 side of things I sometimes get the feeling that for historic reasons a lot of x86 teams were forced to re-ip in DR since A) networks didn't support transparent failover B) not that many workloads existed on x86 that were classed as critical for the business that they needed to be included in any DR strategy, as we all know in the last 5-10 years this swing has shifted massively and now the vast majority of workloads will be running on x86 based OS's. So maybe its time for a re-think?????
What you need to consider are todays "modern" and multi-tier applications (web/msg/rdbms) how many in your portfolio would you expect to work unaided if you simply re-ip'd them? probably not many and confidence is low...for example would you really want to failover lots of oracle/sql srvr/exchange VM's and then give them all brand new ipaddresses. ok they may work if you are VERY confident that the apps respond well to that and that you have been very strict company wide in your use of FQDN's and aliases if not then there's always those hardcoded ipaddresses that can bring your application stacks to their knees if you forget (or miss) to change on. Bottom line, when changing the ip-addresses over you could (not always) introduce a whole extra set of tests that need to be run once the VM's are recovered. The nice thing about SRM is that at least now you can perform these tests in a non-disruptive way which is great but if you feel that in real DR situations you still need to run them no matter how well your testing went then any extra tests added post recovery will obviously add time onto your RTO/RPO points.
hope this helps,
Thanks Lee for your response.
Our customer runs some inhouse developed apps which have IP's hardcoded and that scare me to go with this option. I understand that you have testing phase where you can test and come up with guideline for Re-IP machine. Management have some reservation for going with "RE-IP" approach and wants me to explore "Stretched VLAN". If you can point me to some blog/url/document which talks about "stretched VLAN" that would be great help to me.
PS : I have send you PM
i dont have any specific URLs that really cover HA network design but I would image if you spend a bit of google'ing time searching for keywords like:
highly available enterprise network
you will probably find yourself some useful starting points. If I can find a useful single document that covers some sample architecture I will post the URL.