When / how do we prefer to run HAMMER cleanup? My thoughts:
It is important to cleanup HAMMER file systems regularly, to get snapshots generated and prune & reblock so file system doesn't get too fragment or fill up. This should be done by default; this way users will only get minimal extra administration tasks by using HAMMER. Default action: `hammer cleanup'; with ability to specify other command. command should, just like `hammer snapshot', snapshot, prune & reblock all HAMMER file systems, including PFS. - periodic/daily Executes in the night (starts 3:01 AM). Cleanup by default; ability to disable (periodic.conf). Fine for servers running 24h a day; not good for systems turned off at night. Maybe periodic/monthly should also be used, so extended cleanup won't give disk trashing. - rc.d/hammer_cleanup Executes at boot time. Cleanup by default; ability to disable (rc.conf). Fine for systems turned off at night. I see no problem by enabling cleanup in both rc.d and periodic by default, as `hammer cleanup' is a no op. if executed more than once a day. If users want snapshot more often (eg. every hour), a cron script can do that, this is very light weight to generate; normally it will normally be enough to prune & reblock file system once a day. I can make scripts for this, when we agree on what we want. -thomas
