dscheyen
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Small vsphere deployment

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Good day everyone my name is David and I have the following questions,

We are starting to prepare for building a small vsphere environment with the following specs.

1. total of 7 guest, 2 in DMZ, and 5 vm's in regular network

2. budget of approximately $40000

3. should have HA

4. don't need DRS

5. shared storage

6. vcenter and 2 esxi hosts 6.7

My questions/concerns are

1. this document from vmware states that minimum 3 hosts are recommended for HA/DRS - vCenter HA Hardware and Software Requirements

2. is this true you need minimum 3 hosts for HA or is it just saying for DRS you need 3 hosts?

3. What is the best solution for low budget decent performing shared storage?

4. do you recommend vsan for storage on a small setup? is it expensive?

5. A friend of mine was saying not to use HA and just use vsphere replication to copy vm's to second host in 15 minute intervals, I don't like this idea because of the significant extra disk I/O's and much less flexibility when it comes to patching and failover etc..., is this a legit approach to a poor mans HA?

6. Would you consider hosts with only 1 cpu? the vm's wont be real cpu hungry but I want good performance. (this might be to difficult to answer)

I appreciate any assistance you can proved.

Thank you.

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sk84
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The questions cannot all be answered concretely, as it is very different from use case to use case.

1./2. Basically you only need 2 hosts for HA. But if a part is broken or a host fails, you are not protected until the part or host is replaced. Experience shows that this can sometimes take some time until the error is localized and the hardware is replaced. Also, you are not protected against failures during maintenance. Therefore it is generally considered best practice that a productive cluster has at least 3 hosts. However, it is a risk assessment and a question of your infrastructure and also of your hardware support contract. If you can handle a failure of one or more days or there is an alternative for the running VMs, it might be better to have only 2 hosts to save money.

3. I'm not familiar with low budget storages. Here I would simply get offers and compare. But I recommend you to choose a storage from a well-known manufacturer and maybe something with an SSD cache and automated storage tiering. The storage is one of the most important components in virtualized setup. Both in terms of reliability and performance. So I wouldn't take the cheapest storage from an unknown vendor for productive VMs.

4. With vSAN, I would make comparisons. It can be cheaper. But if you can't or don't want to run an external Witness Appliance or Host, you definitely need 3 hosts for a vSAN cluster.

5. This would be basically feasible and an alternative, but it also has some disadvantages. Above all, it's pointless with your concept. With the small number of hosts and CPU sockets you can license the environment with an Essentials (Plus) license and HA is already included. This is one of the cheapest licensing models and it works easier and better than vSphere Replication.

6. How many CPUs and Cores per CPU you need depends on the workload and VM sizing. So I can't answer that in general. But (as an example): If you only have 7-10 VMs with a normal workload and the VMs have an average of 4 vCPUs, then I would probably recommend to use only 1 CPU with 12-20 cores for cost reasons.

--- Regards, Sebastian VCP6.5-DCV // VCP7-CMA // vSAN 2017 Specialist Please mark this answer as 'helpful' or 'correct' if you think your question has been answered correctly.

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sk84
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The questions cannot all be answered concretely, as it is very different from use case to use case.

1./2. Basically you only need 2 hosts for HA. But if a part is broken or a host fails, you are not protected until the part or host is replaced. Experience shows that this can sometimes take some time until the error is localized and the hardware is replaced. Also, you are not protected against failures during maintenance. Therefore it is generally considered best practice that a productive cluster has at least 3 hosts. However, it is a risk assessment and a question of your infrastructure and also of your hardware support contract. If you can handle a failure of one or more days or there is an alternative for the running VMs, it might be better to have only 2 hosts to save money.

3. I'm not familiar with low budget storages. Here I would simply get offers and compare. But I recommend you to choose a storage from a well-known manufacturer and maybe something with an SSD cache and automated storage tiering. The storage is one of the most important components in virtualized setup. Both in terms of reliability and performance. So I wouldn't take the cheapest storage from an unknown vendor for productive VMs.

4. With vSAN, I would make comparisons. It can be cheaper. But if you can't or don't want to run an external Witness Appliance or Host, you definitely need 3 hosts for a vSAN cluster.

5. This would be basically feasible and an alternative, but it also has some disadvantages. Above all, it's pointless with your concept. With the small number of hosts and CPU sockets you can license the environment with an Essentials (Plus) license and HA is already included. This is one of the cheapest licensing models and it works easier and better than vSphere Replication.

6. How many CPUs and Cores per CPU you need depends on the workload and VM sizing. So I can't answer that in general. But (as an example): If you only have 7-10 VMs with a normal workload and the VMs have an average of 4 vCPUs, then I would probably recommend to use only 1 CPU with 12-20 cores for cost reasons.

--- Regards, Sebastian VCP6.5-DCV // VCP7-CMA // vSAN 2017 Specialist Please mark this answer as 'helpful' or 'correct' if you think your question has been answered correctly.

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dscheyen
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Thank you for the well thought through reply! I agree with all your responses, I think the idea of using replication as a HA alternative is a last resort and will not entertain. Thanks again!

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