You might get an error during the Syneto ESXi upgrade with:


 [InstallationError]
 [Errno 28] No space left on device
       vibs = VMware_locker_tools-light_11.1.1.16303738-16701467
 Please refer to the log file for more details.


Swap size is too small for temporary actions so you need to add a local datastore for swap.


To do that you need to login into your ESXi hypervisor. Go to Monitor -> System -> Swap and Edit Settings.

Change from none to local datastore (in our case datastore1)


Try again to run the update.


https://docs.vmware.com/en/VMware-vSphere/6.7/com.vmware.vsphere.resmgmt.doc/GUID-C0DBB2A3-4B44-45BE-927E-10EEB2EB8CBE.html