On Tue, 5 Mar 2013, Wido den Hollander wrote: > > Wido, by 'user quota' do you mean something that is uid-based, or would > > enforcement on subtree/directory quotas be sufficient for your use cases? > > I've been holding out hope that uid-based usage accounting is a thing of > > the past and that subtrees are sufficient for real users... in which case > > adding enfocement to the existing rstats infrastructure is a very > > manageable task. > > > > I mean actual uid-based quotas. That still plays nice with shared environments > like Samba or so where you have all homedirectories on a shared filesystems > and you set per user quotas. Samba reads out those quotas and propagates them > to the (Windows) client. Does samba propagate the quota information (how much space is used/available) or do enforcement on the client side? (Is client enforcement even necessary/useful if the backend will stop writes when the quota is exceeded?) > I know this was a problem with ZFS as well. They also said they could do "per > filesystem quotas" so that would be sufficient, but for example NFS doesn't > export filesystems mounted in a export, so if you have a bunch of > homedirectories on the filesystem and you want to account the usage of each > user it's getting kind of hard. > > This could be solved if the clients directly mounted CephFS though. > > I'm talking about setups where you have 100k users in a LDAP and they all have > their data in a single filesystem and you want to track the usage of each > user, that's not an easy task without uid-based quotas. Wouldn't each user live in a sub- or home directory? If so, it seems like the existing rstats would be sufficient to do the accounting piece; only enforcement is missing. > Running 'du' on each directory would be much faster with Ceph since it > accounts tracks the subdirectories and shows their total size with an 'ls > -al'. > > Environments with 100k users also tend to be very dynamic with adding and > removing users all the time, so creating separate filesystems for them would > be very time consuming. > > Now, I'm not talking about enforcing soft or hard quotas, I'm just talking > about knowing how much space uid X and Y consume on the filesystem. The part I'm most unclear on is what use cases people have where uid X and Y are spread around the file system (not in a single or small set of sub directories) and per-user (not, say, per-project) quotas are still necessary. In most environments, users get their own home directory and everything lives there... sage > > Wido > > > sage > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- > Wido den Hollander > 42on B.V. > > Phone: +31 (0)20 700 9902 > Skype: contact42on > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
