On linux, it can either get done using fstrim (often run periodically, e.g. via cron), which clears unused blocks, or can be done on file delete on supported fi

On linux, it can either get done using fstrim (often run periodically, e.g. via cron), which clears unused blocks, or can be done on file delete on supported file systems (e.g. mounting using the discard option). The periodic trim is supposed to be better, as a SSD does guarantee that a trim returns quickly. If you want to trim an entire device, see blkdiscard (take care!).