Mattias Pantzare wrote: > 2008/6/6 Richard Elling <[EMAIL PROTECTED]>: > >> Richard L. Hamilton wrote: >> >>>> A single /var/mail doesn't work well for 10,000 users >>>> either. When you >>>> start getting into that scale of service >>>> provisioning, you might look at >>>> how the big boys do it... Apple, Verizon, Google, >>>> Amazon, etc. You >>>> should also look at e-mail systems designed to scale >>>> to large numbers of >>>> users >>>> which implement limits without resorting to file >>>> system quotas. Such >>>> e-mail systems actually tell users that their mailbox >>>> is too full rather >>>> than >>>> just failing to deliver mail. So please, when we >>>> start having this >>>> conversation >>>> again, lets leave /var/mail out. >>>> >>>> >>> I'm not recommending such a configuration; I quite agree that it is neither >>> scalable nor robust. >>> >>> >> I was going to post some history of scaling mail, but I blogged it instead. >> http://blogs.sun.com/relling/entry/on_var_mail_and_quotas >> -- richard >> >> > > The problem with that argument is that 10.000 users on one vxfs or UFS > filesystem is no problem at all, be it /var/mail or home directories. > You don't even need a fast server for that. 10.000 zfs file systems is > a problem. > > So, if it makes you happier, substitute mail with home directories. >
If you feel strongly, please pile onto CR 6557894 http://bugs.opensolaris.org/view_bug.do?bug_id=6557894 If we continue to talk about it on the alias, we will just end up finding ways to solve the business problem using available technologies. A single file system serving 10,000 home directories doesn't scale either, unless the vast majority are unused -- in which case it is a practical problem for much less than 10,000 home directories. I think you will find that the people who scale out have a better long-term strategy. The limitations of UFS do become apparent as you try to scale to the size permitted with ZFS. For example, the largest UFS file system supported is 16 TBytes, or 1/4 of a thumper. So if you are telling me that you are serving 10,000 home directories in a 16 TByte UFS file system with quotas (1.6 GBytes/user? I've got 16 GBytes in my phone :-), then I will definitely buy you a beer. And aspirin. I'll bring a calendar so we can measure the fsck time when the log can't be replayed. Actually, you'd probably run out of inodes long before you filled it up. I wonder how long it would take to run quotacheck? But I digress. Let's just agree that UFS won't scale well and the people who do serve UFS as home directories for large populations tend to use multiple file systems. For ZFS, there are some features which conflict with the notion of user quotas: compression, copies, and snapshots come immediately to mind. UFS (and perhaps VxFS?) do not have these features, so accounting space to users is much simpler. Indeed, if was was easy to add to ZFS, then CR 6557894 would have been closed long ago. Surely we can describe the business problems previously solved by user-quotas and then proceed to solve them? Mail is already solved. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
