Re: receive snapshot, complains about missing file

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

Alexander Fougner posted on Sat, 30 Apr 2016 12:55:06 +0200 as excerpted:

>>> Receive side only outputs this:
>>> sudo btrfs check -p /dev/sdc Couldn't open file system
>>
>> It wasn't mounted at the time, right?
> 
> Nope
> 
> 
>> Cuz btrfs check won't work with a mounted filesystem.
>>
>> Of course you'll need to be root to access the device as well,
>> but that's pretty much a given.
> 
> I think sudo should do that, right?

Yes.

I wonder then why it couldn't access it?

Just to be sure, since I didn't think to ask the first time and with 
subvolumes it's possible to mount other subvolumes and possibly forget 
that they're actually part of the same filesystem, you didn't have /any/ 
subvolumes of that filesystem mounted, right?

What does btrfs fi show say about the filesystem?

I'm assuming it's mountable.  Does a mount and umount then let it be 
btrfs checked?  On the other end of things, what about a reboot and btrfs 
device scan, then btrfs check?

If it's not the low-hanging fruit like that, perhaps check is keying off 
the same error that receive is, but I haven't the foggiest what the 
problem would be.

I guess another possibility would be that btrfs check is violating some 
sort of security policy such as selinux.  I don't run anything of that 
nature here so know little more about it beyond the possibility, but from 
previous posts I think Chris Murphy has at some experience in that area.

-- 
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