Can I use commercial SSD in vSan

[littletown92]

Is it possible to use commercial SSD in a vSAN LAB enviroment, even tough the SSD is not listed in the vmware compatibility guide. And what SSDs would you then recommend on a budget.

[GreatWhiteTec · Accepted solution]

Hi Littletown92,

The component certification listed under the vSAN VCG, provides you with support for the solution, and adequate endurance and performance; depending on what devices were selected. For a lab environment where you only want to test vSAN, you can use other (cheaper) components. Just don't expect great performance, and you may also see some alerts in regards to components not being on the VCG. I have a couple of home labs using Intel NUCs, and those components are certainly not on the VCG, but allows me to test versions of vSAN, and other products as well. Those devices work just fine. If it breaks, it is up to me to fix it.

The better SSDs you can afford, the better performance and endurance you will get. I run some VMs for my IP cameras on my home lab, so I did invest on more expensive (but still cheap) SSDs. It's a matter of what you can afford. I started with 2 nodes, and then expanded, as I was able to get more nodes later on.

Another option is to build a nested lab. This minimizes on the amount of hardware you need, but if a device fails, the entire cluster suffers.

[chris122686]

SSD Selection Requirements

Performance and endurance are critical factors when selecting SSDs. For each of the above use cases, the amount and frequency of data written to the SSD or flash device determines the minimum requirement for performance and endurance by ESXi. In general, SSDs can be deployed in all of the above use cases, but (low end) flash devices including SATADOM can only be deployed in some. In the table below: ESXi write endurance requirements are stated in terms of Terabytes written (TBW) for a JEDEC random workload. There are no specific ESXi performance requirements, but products built on top of ESXi such as vSAN may have their own requirements.

Table 1: SSD/Flash Endurance Requirements

SSD/Flash Device Use Case	JEDEC Endurance Requirement	Workload Charectization	Notes
Host Swap Cache	365 TBW or better	Random, infrequent writes	Host memory rarely overcommitted
	3650 TBW or better	Random, frequent writes	Host memory routinely overcommitted
Regular Datastore	3650 TBW or better1	Virtual Machine workload dependent	Size >= 1TB needs more endurance
vSphere Flash Read Cache (VFlash)	365 TBW or better	Virtual Machine workload dependent	Size <= 4TB
ESXi Boot Device	0.5 TBW minimum2 2 TBW recommended2,6	Sequential (WAF <10)</td>	Size >= 4GB3
ESXi Coredump Device	0.1 TBW minimum2,4	Extremely sequential (WAF ~1)	Size >= 4GB3,4
ESXi Logging Device	64 TBW (dedicated device) 128 TBW (colocated) 2,5	Sequential7 (WAF < 100 block mode, WAF < 10 page mode)</td>	Size >= 4GB2,3

1. For SSD sizes over 1 TB the endurance should grow proportionally (e.g., 7300 TBW for 2 TB).
2. Endurance requirement normalized to JEDEC random for an inherently sequential workload.
3. Only 4 GB of device is used, so a 16 GB device need only support 25% as many P/E cycles.
4. Default coredump partition size is 2.7 GB. See Table 2 for detailed size requirements. When boot and coredump devices are co-located the boot device endurance requirement will suffice.
5. Failure of the ESXi boot and/or coredump devices is catastrophic for vSphere, hence the higher requirement as an extra margin of safety when logging device is co-located with one or both1.
6. Future release of vSphere may require higher TBW for its boot device. It is highly recommended for future looking system to have 2TBW endurance requirements for vSphere boot device.
7. For specific characteristics details of ESXi logging workload and its normalization to JEDEC219 random workload, please contact VMware.