On 03/04/2016 01:27 AM, Paul B. Henson wrote: > On Fri, Mar 04, 2016 at 12:50:15AM -0500, Richard Yao wrote: > >> My vote is for "Please don't integrate without mirror/RAID-Z >> support - all ZFS features should work together." > > I think all the people who have ever accidentally added a non-redundant > top level vdev and screwed themselves with no way to recover would > disagree :). I say add it now, even if only as an undocumented > only-in-case-of-emergency feature. Particularly given there's no > timeline for adding support for those additional features.
Given that this would appear in `zpool upgrade -v`, it would be hard to leave it undocumented. I decided to type up a follow-up email after seeing the support for doing this, but I'll quote it in this reply to make it easier for others to read this: > I probably should elaborate on this. ZFS is intended to make > administration simple. If we start introducing features that are > unnecessarily incompatible with existing features, we risk a future > where the non-interoperability of various features makes OpenZFS > administration into a NP-complete boolean satisfiability problem. > > In addition, some ideas for features are far more incompatible with > other things (e.g. killing checksums, redundancy, compression, etcetera > for O_DIRECT support) have been discussed in private. If this is merged, > the idea that "all ZFS features should work together" is not going to be > a great argument against implementing even less compatible features. > > As useful as this is, I would rather that we not take the first step > toward either scenario. Would anyone that wants this volunteer to implement the mirror/RAID-Z support? This is a feature that we really need, but for the above reasons, I think adding it as-is is a double edged sword. > > ------------------------------------------- openzfs-developer Archives: https://www.listbox.com/member/archive/274414/=now RSS Feed: https://www.listbox.com/member/archive/rss/274414/28015062-cce53afa Modify Your Subscription: https://www.listbox.com/member/?member_id=28015062&id_secret=28015062-f966d51c Powered by Listbox: http://www.listbox.com
