Re: btrfs receive: could not find parent subvolume

[Hugo Mills <hugo@carfax.org.uk>]

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On Thu, Sep 18, 2014 at 08:27:18AM -0700, Marc MERLIN wrote:
> While debugging a btrfs send/receive slow problem, I now getting this:
> legolas:/mnt/btrfs_pool1# btrfs send -p tmp_ggm_daily_ro.20140917_06:29:58 tmp_ggm_daily_ro.20140918_02:48:24 | ssh gargamel btrfs receive -v /mnt/btrfs_pool2/backup/debian64/legolas
> At subvol tmp_ggm_daily_ro.20140918_02:48:24
> At snapshot tmp_ggm_daily_ro.20140918_02:48:24
> receiving snapshot tmp_ggm_daily_ro.20140918_02:48:24 uuid=5d1f0454-1be3-b648-9ea5-dc427cd62d98, ctransid=310713 parent_uuid=d86e69bf-e17f-7f4c-bfb7-e571d5824687, parent_ctransid=308332
> ERROR: could not find parent subvolume
> 
> The parent is there on the other side, but UUID is different:
> gargamel:/mnt/btrfs_pool2/backup/debian64/legolas# btrfs subvolume show tmp_ggm_daily_ro.20140917_06:29:58
> /mnt/btrfs_pool2/backup/debian64/legolas/tmp_ggm_daily_ro.20140917_06:29:58
>         Name:                   tmp_ggm_daily_ro.20140917_06:29:58
>         uuid:                   3d424a2b-69da-244c-bfcc-c283f9cc1f34
>         Parent uuid:            05d3b9be-bfe2-bb4a-9f6a-64b9d44896c7
>         Creation time:          2014-09-17 06:30:01
>         Object ID:              7873
>         Generation (Gen):       83621
>         Gen at creation:        83476
>         Parent:                 263
>         Top Level:              263
>         Flags:                  -
>         Snapshot(s):
> 
> Now it seems that the UUID is different on all my snapshots created by
> btrfs send, so maybe it doesn't match UUID?
> 
> Given that, what is btrfs receive using to get a match?

   There's a "recieved UUID" field on each subvolume. I posted a patch
to userspace a couple of weeks ago which adds a -R option to show it.
I don't think it's filtered through David's backlog yet.

   Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
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