On Thu, Mar 05, 2015 at 11:04:36AM +0900, Minchan Kim wrote: > On Thu, Mar 05, 2015 at 10:47:52AM +0900, Sergey Senozhatsky wrote: > > On (03/05/15 10:33), Minchan Kim wrote: > > > > hm, I can think of a huge build server with tons of users. > > > > /dev/zram$(id -u) > > > > created during user login and destroyed during logout. so users use > > > > theirs own > > > > zram devices with predictable device ids (which also makes it simpler > > > > for admin) > > > > for compilation/etc., and don't pressure hdds that much. > > > > > > They upgraded the system and from now on, one of app tries automatic > > > id with zram for some reason. What happens if he gets some user id > > > before the user login? The system should have fallback in the case of > > > failing to create own userid assignment. > > > > we upgraded our scripts but landed some bugs there? it's up to particular > > implementation. in your example, I assume, someone used zram with > > num_devices >= 1000? > > that's impossible. current num_devices limitation is 32. and uid-s start > > from 1000. > > I meant it. > If we support use-defined id and someone have used your idea so he can make > zram > per-user as uid. After a while, new application stats automatic id assignment > so upcoming users can consume upcoming user id. yeah, automaic id will start > from 0 so it's very rare to reach 1000 but who knows?
Why 1000? The UID_MIN and UID_MAX is nothing strictly defined, it's just option in /etc/login.defs. I guess it's nothing unusually to have system where UID_MIN is 500 :-) Karel -- Karel Zak <k...@redhat.com> http://karelzak.blogspot.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/