On 2016-09-11 13:11, Duncan wrote:
Martin Steigerwald posted on Sun, 11 Sep 2016 14:05:03 +0200 as excerpted:
Just add another column called "Production ready". Then research / ask
about production stability of each feature. The only challenge is: Who
is authoritative on that? I´d certainly ask the developer of a feature,
but I´d also consider user reports to some extent.
Just a note that I'd *not* call it "production ready". Btrfs in general
is considered "stabilizing, not yet fully stable and mature", as I
normally put it. Thus, I'd call that column "stabilized to the level of
btrfs in general", or perhaps just "stabilized", with a warning note with
the longer form.
Because "production ready" can mean many things to many people. The term
seems to come from a big enterprise stack, with enterprise generally both
somewhat conservative in deployment, and having backups and often hot-
spare-redundancy available, because lost time is lost money, and lost
data has serious legal and financial implications.
But by the same token, /because/ they have the resources for fail-over,
etc, large enterprises can and occasionally do deploy still stabilizing
technologies, knowing they have fall-backs if needed, that smaller
businesses and individuals often don't have.
Which is in my mind what's going on here. Some places may be using it in
production, but if they're sane, they have backups and even fail-over
available. Which is quite a bit different than saying it's "production
ready" on an only machine, possibly with backups available but which
would take some time to bring systems back up, and if it's a time is
money environment, then...
Which again is far different than individual users, some of which
unfortunately may not even have backups.
If "production ready" is taken to be the first group, with fail-overs
available, etc, it means something entirely different than it does in the
second and third cases, and I'd argue that while btrfs is ready for the
first and can in some cases be ready for the second and the third if they
have backups, it's definitely *not* "production ready" for the segment of
the third that don't even have backups.
And definitely not for the segment of the second and third who believe
that RAID is a backup.
It brings to mind one of my friends who I was explaining my home
server's storage stack to. When I explained that I could lose three of
the four primary disks and one of the SSD's and the system would still
keep running and be pretty much fully usable, his first response was
'Oh, so you have three backups of the prim,ary disk and one of the
SSD?'. We had a long discussion after that where I explained that RAID
was not a backup, it was for keeping things working when a disk failed
so you didn't have to restore from a backup.
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