It seems that our DXi appliance has had some churn on its data usage recently and managed to fill its datastore to capacity, so much so that it crashed and took all the linux VMs using it as a mount point with it. I managed to move some offline VMs sharing the same datastore to a different one, giving DXi the entire disk to itself (a single 1tb drive). Now it has about 100gb of breathing room left from ~960gb of total space.

My question is this: Per the admin panel there's 600gb of 'raw' data squished down to about ~200gb of actual disk usage. On a linux or Windows VM I can have the OS write out zeros to unused space, shut the VM down gracefully, then have ESXi 'h*** punch' the disk to reclaim unused space.

Since I can't log into the DXi's consolde (it appears to be Centos based), and there is no GUI option, how do I handle this 600gb(200 really) of data actually taking up about 800gb on my disk?