Currently the ESXI boxes having the version 126.96.36.19900 and planning to upgrade the boxes .What is the recommended version we have to upgrade .
And also we dont have the DRS configured in the boxes ,so we have to shutdown the vm's before upgrading the ESXI box .
Kindly know what is the pre check we have to keep in mind and any issues faced earlier by anyone .
The upgrade version depends on the hardware compatibility. You have to check the "matrix compatibility".
If DRS is not configured, you can manually move virtual machines with "vmotion" to another host.
If you write the brand, model and cpu type, I can give indications.