Am Mittwoch, den 29.09.2010, 19:54 +0200 schrieb Jasse Jansson: > On 09/29/10 03:47 PM, Rumko wrote: > > Stathis Kamperis wrote: > > > >> 2010/9/28 Rumko<[email protected]>: > >>> Stathis Kamperis wrote: > >>> > >>>> 2010/9/28 Sdävtaker<[email protected]>: > >>>>> What i tried to sai about history was that user usage should be > >>>>> measured in a different bag than the history that the user usage > >>>>> generated. > >>>>> Sorry if it was not clear, english is not my main language and i use > >>>>> to fail time to time. :-/ > >>>>> Damian > >>>>> > >>>> I kind of agree. > >>>> > >>>> Why "punish" user for something that s/he is not able to control > >>>> directly ? Even more, the user may not be aware of the underlying > >>>> filesystem's technicalities (how it retains history and so on). > >>>> > >>>> Better come up with something else. > >>>> > >>>> Best regards, > >>>> Stathis > >>> Not punishing that user means punishing the whole system and everything > >>> depending on that system. And as I said before, it's user's data, so who > >>> should be punished if not the user? The user can always tell the admin > >>> that > >>> he does not any history at all or how much history he needs, so it's > >>> purely > >>> that user's responsibility ... his data, his rules, his reponsibility. > >>> [...] > >> Ok, fine. I'm not strongly opinionated on this. I'm just thinking from > >> the Josephine perspective, who may not (or even want to) know how her > >> file-system operates. > > Then that user's home dir can be nohistory and there is no problem? > > If she doesn't need multiple copies of her data, then I see no reason why to > > keep that data. But if she wants n snapshots/backups then there should be a > > limit on how much total space she can take. Otherwise we could just display > > du -h of her home dir when she logs in and it would be about as useful at > > limiting her disk usage, so there would be no point to a quota ;) > > On purpose she could bring down the whole system at will even though she > > was "limited", but unfortunately she could do it unknowingly as well > > (downloading flash videos, powerpoint jokes, maybe a movie or two, etc. over > > and over and rewriting the old files). > > > >> But if we go this route, then we should also provide history retention > >> statistics to user-land utilities, such as df(1). > >> > >> Imagine the confusion of a user that types 'df', sees that the quota > >> threshold hasn't been reached, yet she is denied further disk storage > >> allocation. > > Agreed, now we just need to find someone to do it :P > > While you're at it, why don't make two kinds of snapshots. > > 1. A user initiated snapshot, usnap, that the user controls and counts > towards the quota limit. > > 2. System snapshots, ssnap, obviously managed by the system/admin (out > of control of the user) and therefore counts as system overhead.
Well, that would be doable but would need some hacking in hammer cleanup. And the cleanup/reblock process does not know about file names, only inode numbers AFAIK, so that every usnap would end up in generating a full PFS snapshot. It is clearly doable, but would probably be very inefficient. But, hmm, telling "hammer cleanup" to throw away history for "*.bak" or other "unused" files would be nice :). But then, snapshots right now are beautiful as they are so easy to use and you cannot make much wrong. Regards, Michael
