FT Second VM can't be created problem

Hello everyone

i'm running two ESXI 6.0 U1 on both

current configuration :

ESXI 1 :

HP ProLiant DL380p Gen8

Intel(R) Xeon(R) CPU E5-2609 0 @ 2.40GHz

RAM : 48 Go

Storage : 2 TB

ESXI 2 :

HP ProLiant DL380p Gen8

Intel(R) Xeon(R) CPU E5-2609 0 @ 2.40GHz

RAM : 48 Go

Storage : 2 TB

i created a cluster , activated HA and i have a VM of 16 Gb of ram

created fixed disks fully provisioned of C: 135 Go  E: 500 Go  F: 600 Go

so the VM is running on ESXI 2 and is currently using 1,21 To

so my problem is when activating the FT on this VM it stops with a message of : No Compatible Host for the Fault Tolerance secondary VM

and when i shut down the vm and activate the FT it works but when i start the VM it cannot start also

can anyone help me to view or debug the logs on why the Faul Tolerance can't be activated

and thanks