> On Jun 3, 2016, at 2:44 PM, Josh Paetzel <j...@tcbug.org> wrote: > > However, is that really realistic that we're going to write that sort of > thing up and someone will be able to follow it as sort of a recipe > without really understanding what they are doing? If someone is that > clever they've probably already figured out how to do all of this.
No, I suspect the best we’re going to be able to do is write up a few recipes for “minor damage recovery” scenarios (like rolling back a TXG, looking for backup uberblocks a Richard suggested, etc) and expect that the sufficiently motivated person will extrapolate from there. What you may be overestimating is the amount of general knowledge that is out there for even doing that much - you know everything you just wrote up because you’ve worked for a ZFS Storage company for ~8 years (I’m guesstimating) and you’ve debugged dozens, if not hundreds, of customer scenarios where you were Highly Motivated to figure out a recovery technique, assuming any was available. That kind of experience, or even the basic fundamentals you learned along the way, doesn’t come cheap nor is it widely held. By contrast, filesystems like UFS or FAT (both admittedly far simpler technologies) have had so many decades of soak time that there is now a wealth of institutional knowledge and commercial recovery tools that leverage that institutional knowlege to recover them, extract individual files from them, and otherwise delve through any number of tortured, twisted bytes to extract key and irreplaceable information. I am not suggesting that we can turn novices into ZFS experts through a FAQ, or anything even close, but it seems like this is one of those subject areas that is complex enough to discourage even trying, and that’s a shame. That said, I should go read Michael Lucas’ ZFS mastery book - perhaps he sheds some light on this, and if so, that will go some way towards providing a literally off-the-shelf source of information on the subject. Even better, I’ll just CC him on this email, assuming he’s not already on this list and reading the thread. :) - Jordan ------------------------------------------- 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
