capacity tier design

[miladmeh8]

Hi All,

I have a question, as you know better to have 10% of capacity tier in cache tier. according to vSAN maximum which says for vSAN 7 the maximum supported cache tier is 600 GB then do I have to have maximum 6TB in each disk group?

another question I have two 256 GB SSD disk on a server can I use both of them in one diskgroup ? or I have to use only a single disk in cache tier? if both possible which one is recommended?

Regards,

[Octopus_L4]

Hi,
have you tried looking at vSAN ReadyNode Sizer ? Maybe it will help.
https://vsansizer.esp.vmware.com/login?returnUrl=%2Fhome

[Brisk]

With vSAN 8 that limitation was raised to 1,6 TB instead of 600 GB. vSAN will let you create the disk groups just fine even if the percentages don't line up. But you may run into performance issues if your workloads blow through the cache tier that you have available.

As @Octopus_L4 said, check out the vSAN sizer and play around with it. Also make sure to read the resources available here https://core.vmware.com/vsan-plan-and-design to get a better understanding of how to design and size your environment.

For your second questions - you can only use 1 cache disk per disk group. If you wish to use both SSDs, you need to create 2 disk groups.