There are no default CLI utilities that support this right off the bat but you can take a look at using vSphere SDK for Perl or PowerCLI to accomplish this task.

Take a look at EnableSecondaryVM_Task() to enable FT and DisableSecondaryVM_Task() to disable FT. If you provide the credentials either through a config file or hardcode it within the script, then you can setup a Windows scheduled task to enable/disable FT, but you won't be able to schedule this within vCenter itself. You can also set the script run via a cronjob if you're using a UNIX/Linux or even vMA to execute the script.

If I get some free cycles this week, perhaps I'll write up a quick Perl script to show how this is done, but the methods are pretty straight forward and so long as you have the appropriate license for FT.

=========================================================================
William Lam
VMware vExpert 2009
VMware ESX/ESXi scripts and resources at: http://engineering.ucsb.edu/~duonglt/vmware/
vGhetto Script Repository
VMware Code Central - Scripts/Sample code for Developers and Administrators
http://twitter.com/lamw



If you find this information useful, please award points for "correct" or "helpful".

Take a look at this script: http://www.yellow-bricks.com/2009/07/01/ftcli-pl-vmware-fault-tolerant-managment/

=========================================================================
William Lam
VMware vExpert 2009
VMware ESX/ESXi scripts and resources at: http://engineering.ucsb.edu/~duonglt/vmware/
vGhetto Script Repository
VMware Code Central - Scripts/Sample code for Developers and Administrators
http://twitter.com/lamw



If you find this information useful, please award points for "correct" or "helpful".