Re: Significance of high number of mails on this list?

[Filipe David Manana <fdmanana@gmail.com>]

On Fri, Aug 22, 2014 at 8:35 AM, Duncan <1i5t5.duncan@cox.net> wrote:
> Konstantinos Skarlatos posted on Fri, 22 Aug 2014 09:56:55 +0300 as
> excerpted:
>
>> I would stay with rsync for a while, because there is always the
>> possibility of a bug that corrupts both your primary filesystem and your
>> backup one, or send propagating corruption from one filesystem to
>> another (Or maybe I am too paranoid, it would be good if we could have
>> the opinion of a btrfs developer on this)
>
> No claim to be a dev, btrfs or otherwise, here, but I believe in this
> case you /are/ "being too paranoid."
>
> Both btrfs send and receive only deal with data/metadata they know how to
> deal with.  If it's corrupt in some way or if they don't understand it,
> they don't send/write it, they fail.

Most of the time yes, however we have at least 1 know bug that affects
3.14.x only where send silently corrupts file data (replaces valid
data with zeroes) at the destination:

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=766b5e5ae78dd04a93a275690a49e23d7dcb1f39

The fix landed in 3.15, but wasn't backported to 3.14.x yet (adding
Chris to cc).

>
> IOW, if it works without error it's as guaranteed to be golden as these
> things get.  The problem is that it doesn't always work without error in
> the first place, sometimes it /does/ fail.  In that instance you can
> always try again as the existing data/metadata shouldn't be damaged, but
> if it keeps failing you may have to try something else, rsync, etc.
>
> --
> Duncan - List replies preferred.   No HTML msgs.
> "Every nonfree program has a lord, a master --
> and if you use the program, he is your master."  Richard Stallman
>
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-- 
Filipe David Manana,

"Reasonable men adapt themselves to the world.
 Unreasonable men adapt the world to themselves.
 That's why all progress depends on unreasonable men."