It's more work, but...

you have to stop the VM and export them, delete the current SR (Local Storage), recreate SR (Local Storage) as local ext4 format import the VM back

In this way you switch from LVM to ext4 and the space it needs will be small, not double the space

@sumansaha In summary , I've deleted Orphan VDIs from Dashboard->health . But in deletion, I've maintained the sequence of their age.It has taken 6 hours, though that depends on the VM size.