vcenter vsphere with hosts in esxi 3.5

[LMSSML]

HI there !

I would like to know distinct things.

First if I migrate vcenter to vsphere could I maintain my hosts on ESX 3.5i ?

Or must I have at least one host on vsphere and the others in ESX 3.5 i ?

The second thing is if I upgrade one host is this host will write any data on storage ? (worldwidenames of hosts on storage)

Thanks

for the help

[marcelo_soares]

Usually the first thing to do is to upgrade vCenter to 4 and after that upgrade the ESX hosts. You CAN maintain your hosts on the 3.5 version, but you are encouraged to upgrade as soon as possible.

If you have VMFS datastores on a SAN, they will keep being accessed by ESXi 4 hosts (with same WWN and can be shared with ESXi 3.5). I didn't understood what you mean by "write data on storage"...

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[LMSSML]

Hi thanks for the awnser marcelo.soares.

But what would i like to know if there is any risk of after migration of the hosts (connected by fiber) they would write some information to storage or if maitains the same as ESX3.5i.

Usually the first thing to do is to upgrade vCenter to 4 and after that upgrade the ESX hosts. You CAN maintain your hosts on the 3.5 version, but you are encouraged to upgrade as soon as possible.

Is it possible to maintain the hosts on esx3.5i and work with vcenter vsphere4 there is no problem with that ?

Because I thought reading somewhere that at least one host must be in vsphere4 to connect the infrastructure to vcenter.

But tanks for the advice.

[marcelo_soares · Accepted solution]

There is no reason to hav at least one host upgraded. You will be able to connect to vCenter 4 and to the ESX 3.5 hosts using the vSphere Client (in fact, you will have the VI Client and the vSphere client installed).

I only have some concerns on maintaining this scenario for a long time because maybe you can be running into some buggy issue not covered by vmware - example, sometimes you can have problems on datastore properties view with 3.5 ESX under vCenter 4.

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[LMSSML]

Hi marcelo.

What problems have you experienced with the datastores and hosts on Esx 3.5i (what kind of problems ?)

[marcelo_soares]

I had only 2, one related with HA agents inside the hosts amd the other one related with adding extents to pre-existing datastores. The second one was nor resolved by VMware support and I think they are not considering doing this since there are workarounds for the problem.

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[LMSSML]

Hi thanks for the awnser

The situation can be reverted if you run again the vcenter for ESX 3.5, or it isn't advisable ?

Thanks for sharing your experience .

[marcelo_soares]

You can revert the installation, but not the database. You will need to uninstall vCenter 4 and ease the database instance for VCDB (you will loose your perf data and configurations for vCenter). After that you can install the 2.5 version.

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[LMSSML]

HI thanks Once again

But if I make a clone of virtual center and then update my clone to vsphere I still remain with a vcenter old .

The question here is if the hosts will loose configuration when shutdown a vcenter vsphere and bring up vcenter esx 3.5i, I have in mind that it wouldn't be affected.

Is that right ?

Thanks.

[marcelo_soares]

Hmm... no, they will not go back automatically if you bring back the old vCenter. When you connected the ESX hosts to the new vCenter, the ESX agents were upgraded to the 4 version, what will not work on the vCenter 2.5. You will need to remove the hosts from the vCenter 4, bring back your vCenter 2.5, and reconnect all your ESXs to it. With some luck you will not loose the configurations on the old vCenter.

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[LMSSML]

Hi there ,

One last question to close this

Did you have downtime with expanded partitions or the machine stop working ?

After update the agent on host to v4 would it be possible to downgrade the agent to 2.5 agent on hosts ?

Of your experience on migrating could be the hosts in vsphere loose access to storage ?

Did you lost any vm ?

Thanks.