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From: Andrei Borzenkov <arvidjaar@gmail.com>
To: Matt Zagrabelny <mzagrabe@d.umn.edu>,
	Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: help with mounting subvolumes
Date: Fri, 24 Mar 2023 20:58:55 +0300	[thread overview]
Message-ID: <0cf5a777-53b5-7f49-05ae-3fa732689154@gmail.com> (raw)
In-Reply-To: <CAOLfK3VnoHksj2J-r-r360yJ6T6Dd1LX2iTNJ9njmmfttvc8bg@mail.gmail.com>

On 24.03.2023 20:20, Matt Zagrabelny wrote:
> Greetings,
> 
> I do not use subvolumes (yet). I've searched the internet for some
> tutorials on mounting subvolumes, but the documentation seems lacking.
> 
> So far, I've tried...
> 
> # btrfs subvolume create /foo
> # mount -t btrfs -o subvol=foo,defaults,nodatacow
> /dev/disk/by-uuid/5f33a159-4475-44e5-a5f8-40a23e18983a /mntfoo
> mount: /mntfoo: mount(2) system call failed: No such file or directory.
>         dmesg(1) may have more information after failed mount system call.
> 
> However /mntfoo exists:
> 

It does not say "mount point does not exist".

Argument of subvol= option must be full path from the top level 
directory. You root filesystem most likely is already located in one of 
btrfs subvolumes, so subvolume foo is inside other subvolume and you 
need to provide full path.

tw:/home/bor # mount /dev/vda2 -o subvol=foo /tmp/foo
mount: /tmp/foo: mount(2) system call failed: No such file or directory.
        dmesg(1) may have more information after failed mount system call.
tw:/home/bor # mount /dev/vda2 -o subvol=/@/.snapshots/1/snapshot/foo 
/tmp/foo
tw:/home/bor #



  reply	other threads:[~2023-03-24 18:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-24 17:20 help with mounting subvolumes Matt Zagrabelny
2023-03-24 17:58 ` Andrei Borzenkov [this message]
2023-03-27 17:14   ` Matt Zagrabelny

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