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From: Nikolay Borisov <nborisov@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: Re: how do I know a subvolume is a snapshot?
Date: Wed, 17 Jul 2019 13:11:36 +0300	[thread overview]
Message-ID: <b2410ac6-34f9-f459-8301-c70fcbe6159e@suse.com> (raw)
In-Reply-To: <20190717091100.GC3462@tik.uni-stuttgart.de>



On 17.07.19 г. 12:11 ч., Ulli Horlacher wrote:
> On Wed 2019-07-17 (11:24), Nikolay Borisov wrote:
>>
>>
>> On 17.07.19 3. 2:24 G., Ulli Horlacher wrote:
>>
>>> I thought, I can recognize a snapshot when it has a Parent UUID, but this
>>> is not true for snapshots of toplevel subvolumes: 
>>
>> As you have asked this before - in my testing this is not true.
> 
> It is true on all my SUSE and Ubuntu systems, for all versions.

That's strange, as I've shown in the previous thread, using the latest
master doesn't exhibit this behavior.
> 
> 
>> Alternatively you have to parse the root tree - the ROOT_ITEM's offset
>> member should be 0 for well-known trees/ordinary subvolume or the
>> transaction id when the snapshot was created.
> 
> Where can I find this ROOT_ITEM offset member? Which command?

btrfs inspect-internal dump-tree -t 1 /dev/vdb

> 
> 

  reply	other threads:[~2019-07-17 10:11 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-16 23:24 how do I know a subvolume is a snapshot? Ulli Horlacher
2019-07-17  7:45 ` Bernhard Kühnel
2019-07-17  8:05   ` Ulli Horlacher
2019-07-17 10:33   ` Remi Gauvin
2019-07-17  8:23 ` Hans van Kranenburg
2019-07-17  8:57   ` misono.tomohiro
2019-07-17  9:06     ` Ulli Horlacher
2019-07-17  9:24       ` misono.tomohiro
2019-07-17  8:24 ` Nikolay Borisov
2019-07-17  9:11   ` Ulli Horlacher
2019-07-17 10:11     ` Nikolay Borisov [this message]
2019-07-17 10:29       ` Andrei Borzenkov
2019-07-17 11:19         ` Nikolay Borisov
2019-07-17 17:39           ` Andrei Borzenkov
2019-07-17 18:16             ` Nikolay Borisov

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