janakors
Contributor
Contributor

breaking Vsan from cluster

hi everyone

i am new to vSAN and wanted to seek help on one of the issue. i want to break my VSAN undelying on 4 blades. these 4 baldes are on single cluster .so what is the deatil procedure to do so if please someone suggest some document to read first and then come to this forum please recommend.

Thank You in advance

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14 Replies
T180985
Expert
Expert

What do you mean you want to break it? Are you wanting to stop using vSAN?

Please mark helpful or correct if my answer resolved your issue. How to post effectively on VMTN https://communities.vmware.com/people/daphnissov/blog/2018/12/05/how-to-ask-for-help-on-tech-forums
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MikeStoica
Expert
Expert

What exactly you want to do? You want to create a vSAN cluster out of the 4 Blades?

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janakors
Contributor
Contributor

no i want free my 4 physical blades from Vsan. i dont want to use vSAN for these blades i.e i need to put it in mainatenance mode and after pre check i will fully migrate

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T180985
Expert
Expert

See this kb which explains how to do it  VMware Knowledge Base

Please mark helpful or correct if my answer resolved your issue. How to post effectively on VMTN https://communities.vmware.com/people/daphnissov/blog/2018/12/05/how-to-ask-for-help-on-tech-forums
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TheBobkin
VMware Employee
VMware Employee

Hello janakors

Unfortunately what T180985  mentioned won't work here as that is the process for decommissioning a single node, not a cluster - If you tried that here (assuming RAID1 Storage Policy and enough  free space), it would just evacuate the first nodes data onto the remaining 3 nodes and then when you try to do another node it would fail and inform you it has insufficient Fault Domains to proceed with this task.

Do you have any data you need on the vsanDatastore? If you do, where are you planning on moving this to? e.g. to a SAN/external datastore or local VMFS datastores made with the vSAN disks.

If you don't have any data you need then just remove the Disk-Groups and disable vSAN on the cluster level.

Bob

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janakors
Contributor
Contributor

Thank you for the link

i tried to put my host in maintenance mode with Full Data Migration but it don't and dispaly message that "1 more standalone host is required. some objects will become inaccessible or non compliant with their storage policy"

my complete scenerio is that i have a cluster of 4 Esxi hosts and there is no VM on these hosts. i want to remove VSAN node completely form all these 4 nodes and want to have these nodes free for some other tasks. please how can i put all these in manintenance mode with Full Data Migration as i want to permanenetly remove them.

other question is that how can i change the storage policy for this cluster only as i think if PFTT=1 so if i succeded to remove 3 hosts so the last one wont remove dut to PFTT=1 so no node in the cluster so where he will migrate my data

please advise

Regards

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janakors
Contributor
Contributor

ooops i didnt see the last reply

yess thank u for reply infact i dont have any data on it i just want to fre my hosts and at the end will delete it from Vcentre. please tell me some more details how to do it

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TheBobkin
VMware Employee
VMware Employee

So that you are aware "there is no VM on these hosts" - this does not mean there is no data on the vsanDatastore e.g. a unregistered VM won't show in vSphere inventory but still resides on the datastore.

If you are 100% sure you require no data from this cluster then proceed as per my last comment (with No Action option for Disk-Group removal).

Bob

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TheBobkin
VMware Employee
VMware Employee

Remove the Disk-Groups so that the partitions are removed from all devices:

Remove Disk Groups or Devices from vSAN

Following this you can validate that all partitions have been removed by either looking at each device at:

Host > Configure > Storage Devices > Select Device > Partition Details

or

Cluster > Configure > Disk Management - on each host you should see for example '0 of 3' devices available if you had 3 devices in use that are no blank.

Disable vSAN on the cluster:

Cluster > Configure > Services/General (depends on Client used) > Turn Off/unselect box:

Disable vSAN

Bob

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janakors
Contributor
Contributor

superb Thank You .

and i did it like first i disconnect its network (every host) and then remove it but i will follow yours as it is more logical

but my question is that if i have 4 host in cluster with storage policy of raid 5 , now if i want to remove 2 host from it so how can i do it as per my perciption it wont as it won't enter in maintenance mode with full migration if space is the issue and what else issue can be there in such scenerio? and if issue is there then as solution how should i remove 2 x host from it? should i loose my data? how to coupe such situation?

please comment

Regards

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TheBobkin
VMware Employee
VMware Employee

Hello janakors​,

"but my question is that if i have 4 host in cluster with storage policy of raid 5 , now if i want to remove 2 host from it so how can i do it as per my perciption it wont as it won't enter in maintenance mode with full migration if space is the issue and what else issue can be there in such scenerio?"

1. Why are you concerned about Storage Policies/compliance if you are deleting anything that is on the cluster?

2. Why are considering using FDM Maintenance Mode option if you are planning on deleting any data that is on the cluster?

"should i loose my data?"

Please if you can clarify your situation here, do you or do you not have data on this cluster that you wish to keep/migrate?

You stated previously "i dont have any data on it i just want to fre my hosts and at the end will delete it from Vcentre."

Bob

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janakors
Contributor
Contributor

well TheBobkin that story is finished . i did what u have told me and the hosts are free. i am putting another situatuon (example). i think i should start new thread for that but as we are in very good context of the overall subject of removing host from VSAN so that why i have started it. now folllowing is the example

e.g if i have 4 hosts in a vSAN and raid 5 is implemented on it and every VM is usung this default polciy of Raid 5 and then my management decide that remove 2 hosts from this VSAN and we want to use it for some other purpose (its just an example) so here if i want to remove 2 hosts permanently so i will put them in maintenance mode with full migration of data but when i do it it doesnt allow me to do it as some objects / componenets getting compromised so at this situation what should  t odo ? what should i consider? i havn't encounter such example but it may happen due to my management as the hardware is too costly to purchase more ?

please advise me some artcles / guides etc so i can proactively counter such situation and have confidence to tell the management that yes we can remove or NO we can;t remove

anything to read from scratch so can do such things as i have told i am new to this whole virtualization field.

please guide

Regards

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TheBobkin
VMware Employee
VMware Employee

janakors, the main point is the minimum host/node requirements for the Failures To Tolerate(FTT) with the Fault Tolerance Method (FTM) in use - if you want/need to use FTT=1,FTM=RAID5 this is 4 nodes, if using FTT=1,FTM=RAID1 this is 3 nodes, FTT=0,FTM=RAID0 it is technically 1 node (though of course this is not a good idea nor supported).

Thus you can't create or retain availability of RAID5 data with just 2 nodes - if this were a bigger cluster (6+ nodes) then provided there is the capacity and compute resources available to store and run all VMs, taking 2 nodes out of it shouldn't pose issues.

But if you only have 4 nodes (and are not tight on space and good at managing it) then going FTT=1,FTM=RAID1 would allow removing a node in future, or if the workload has relatively low space requirements you could even do a 2-node and run the witness on other infrastructure.

"so i can proactively counter such situation and have confidence to tell the management that yes we can remove or NO we can;t remove"

The main takeaway should be that you should not be removing nodes from a cluster beyond what the Storage Policies in use require to function and retain data availability and redundancy.

There are plenty of resources available for further information, but what I would advise starting with is if you want information about specific areas or aspects (e.g. basics cluster-designs and types) then storagehub should be your go-to:

Cluster Types | VMware vSAN 6.7 Technical Overview | VMware

Bob

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janakors
Contributor
Contributor

Great ! thank You for Your Time . i will study and will be in touch

Warm Regards

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