Re: [BUG?] btrfs scrub -d doesn't scan all devices

[Duncan <1i5t5.duncan@cox.net>]

Christoph Anton Mitterer posted on Mon, 28 Dec 2015 02:21:28 +0100 as
excerpted:

> On Sun, 2015-12-27 at 07:22 +0000, Duncan wrote:
>> I'd call that NOTABUG.  As the btrfs-scrub manpage suggests:
>> 
>> * When you point scrub at a mountpoint, it scrubs all devices composing
>> that filesystem.

> Uhm,.. mine doesn't contain this,... neither do those of the master or
> devel branches from David's repo... or am I just blind?

I see that Chris Murphy just filed a bug on it with the particulars, but 
just to clear this up...

That's my paraphrase of what it says, thus the "suggests", but I do 
specifically quote, with "the manpage specifically says" and quote marks, 
so it's pretty hard to miss, which I /thought/, along with "suggests", 
should make it clear that I was NOT specifically quoting the manpage in 
the bullet-point.

Apparently not...

> Actually it says:
>>DESCRIPTION
>>       btrfs scrub is used to scrub a btrfs filesystem, which
>>       will read all data from all disks and verify checksums.

Look under scrub start...  as you did in a followup...

>> Since /dev/disk/by-*/* are symlinks to various block-device nodes, it
>> follows that if you point scrub at them, only the device pointed at is
>> scrubbed, exactly as one might expect based on the manpage.

> Sure... that was clear... but I have another manpage than yours...
> perhaps some distro specific patch?

No, just both a slightly more specific part of the manpage, under scrub 
start, and a mistake in believing "suggests" implies or explicitly 
specifies a direct quote, even when a direct quote is later actually 
made, complete with quotation marks and "the manpage specifically says" 
attribution.

btrfs-progs v4.3.1, if it matters.

-- 
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