Migrate iSCSI from ESXi Hosts to VCenter Distributed Switching

Marlon Chung
Marlon Chung used Ask the Experts™
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How to Migrate iSCSI from ESXi Hosts to VCenter Distributed Switching
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Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Are you using Standard Switches at present ?

Author

Commented:
yes I am for iSCSI

Author

Commented:
Any suggestions?
VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
Commented:
So re-create your new iSCSI Storage on your Distributed Switches, using similar IP Address range as current, and then just re-scan the storage adaptor.

If you currently have Live LUNs, and Live datastores, and LIVE VMs, you are going to have to shut them down, because there will be a break in service. (moving iSCSI)

Author

Commented:
the problem is right now I only have one VM which is the VCenter appliance running. I also only have one ESXi host which is where VCenter is on. however, I do have multiple NICs

Author

Commented:
how do you suppose I migrate it with only one host with vcenter running on that host?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
You only have a single host in your cluster ?

Author

Commented:
for now yes, I have two more hosts I will be adding this weekend
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
To be honest with you, you are really complicating things with Distributed Switches, with so few Hosts!

Distributed Switches are usually used when you've got many hosts, and you want to ensure networking is the same throughout, Distributed Switches do have some features not found in standard switches.

So 3 hosts max ?

Author

Commented:
yes but that will grow and I understand the benefits of distributed switching even with just a few hosts, but for now, only 3 hosts
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Are you a VMware Beginner ? first implementation ?

Author

Commented:
no, I have been using vcenter for quite a while now and my iSCSI has been on VSS up to this point but I wanted to rebuild by entire VCenter. so wanted to do some resting to get iSCSI on VDS

Author

Commented:
prestage, not resting..lol

Author

Commented:
basically, I have a new storage Dell R730XD with Freenas and a new Dell R610 and wanted to pre-stage and get iSCSI on VDS
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
This is an issue if you have the VM on share storage.

Do you have any local storage you could migrate it back to temporary ?

or other network storage you could use as temp, e.g. NFS mount ?

Author

Commented:
Yes, my initial thought was to migrate the VCenter VM back to local storage on the hosts.

My final hardware setup will be 5 x ESXi Hosts 6.7 U3

Each host will have 4 x 10GB SFP+ ports and 4 x 1GB copper ports.

Author

Commented:
So that being said, based on your experience, are most customers using VSS for iSCSI or are they using VDS instead?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
5 hosts still not many to complete a VDS, usually people do VDS of an easy method to ensure networking is the same for all hundreds of hosts.

Anyway as for iSCSI some still do VSS for iSCSI, on individual hosts, and just complete 2 or 4 bindings depending upon available speed of nics and SAN.

some do VDS for everything.

It depends on your overall network design which should in place on paper before implementation and depending upon switch hardware.

If you have local storage good, migrate it back... complete all your new changes and design... when done move back.

Author

Commented:
ok great. thank you

Author

Commented:
I followed your link on multipath iSCSI as I will have 2 x 10GB ports per host. I have always kept the esxi management ports on VSS, if I migrate them to VDS, will I have access to the hosts management no matter what happens to VDS or should I just leave it on VSS?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Yes, you would always have access to the hosts, because vCenter Server is only used to configure VDS.

Have a look at this comparison between VSS and VDS.

https://www.vembu.com/blog/standard-switch-and-distributed-switch-configuration-and-comparison/

Author

Commented:
ok thanks

Author

Commented:
Key Point from your link

Each ESXi host contains a cached copy of the vSphere Distributed Switch configuration that is updated automatically every five minutes. When vCenter has failed or is down, the VDS will continue to function normally and all virtual machine traffic will go unaffected by the vCenter outage.

Thanks,
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Correct, vCenter Server is just used to configure it VMware, designed it that way......

Author

Commented:
I have an issue with my vmkernel adapters not responding to ping requests. I followed the sample setup here from this link

Pure Storage

From each ESXi hosts, the 10GB ports are connected to a Cisco switch with the assigned VLAN that is unique to the two port groups created in the ISCSI vDS which are VLAN 13/14. The VLAN's are also created in each iSCSI port group.

All network binding is done for each hosts in the iSCSI software adapter.

Any idea of what I could be missing?

Thanks,

Author

Commented:
By the way, if you are free I can schedule you in the Live section
Distinguished Expert 2017

Commented:
Vlan, access rules between vlans and whether icmp requests are acknowledged.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Your current issue really needs a new question posting, rather than tagging on this question.

Author

Commented:
I wanted to keep you as my consultant is why I kept it in this thread. I will open up a new case. thanks
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Thanks for your kind words, but there are also many Experts at Experts Exchange can help and supply good information to fix your issue.

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