Hi niall, yes, you're right, when we think in terms of big servers with large amount of data storages, a lot of users and a lot of network mounts the only one way to make it work is to use very simple mechanism as you describe: assume that user have enough free space in home directory and copy all deleted files there.
But! OpenSolaris become available on the usual computers too, now it can be used on home desktop system or even on notebooks (as I know, Toshiba will sell some of their notebooks with OpenSolaris preinstalled), so, it's time to think about limitations of desktop systems: not a lot of users, usually no constant mounts, but limited disk space. For example, my first installation of OpenSolaris was made on 10Gb partition (for rpool, so this is for entire system and user homes) with 300Gb of storage for all other stuff (including download location). And my first experience was deleting of several 1-2Gb files downloaded via Transmission, which was finished with 'pool usage is more then 80%, all automatic snapshots were deleted' (before I stop copying this 15Gb to home located trash folder with 10Gb for entire partition). I even reported a bug for Transmission, but together with developer we decide 'same as Nautilus' and close it. BTW, snapshots is not a god idea in this situation too: when user try to reduce disk space usage, found a 10-20-30Gb of files to be deleted, and even delete it, the only one way to free disk space is manually delete every snapshot made with this files. That's why I propose to start thinking in terms of usual user, not as system administrator of server with unlimited disk resources :) -- This message posted from opensolaris.org