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public:btrfs_snapshot_size [2016/04/01 20:21] fangfufupublic:btrfs_snapshot_size [2018/03/31 00:38] (current) – external edit 127.0.0.1
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 +====== BTRFS snapshot size ======
 +  * First you need to enable quota
 +<code bash>
 +sudo btrfs quota enable /home
 +</code>
 +  * You need to wait for BTRFS so scan the filesystem for quota usage, then
 +<code bash>
 +sudo btrfs qgroup show /home
 +</code>
 +  * You get output which looks like this:
 +<code>
 +qgroupid         rfer         excl
 +--------         ----         ----
 +0/5         142.21GiB     89.70MiB
 +0/410        96.00KiB     96.00KiB
 +0/2191       17.62GiB        0.00B
 +0/3237      137.90GiB      4.05GiB
 +</code>
 +''qgroupid'' is the snapshot ID, ''rfer'' is the total size of that snapshot (the size of the parent subvolumes are included), ''excl'' is the exclusive space that particular snapshot occupies. 
  
 +===== Deleting snapshots =====
 +
 +
 +  * You can list all the subvolume by running this: 
 +<code bash>
 +sudo btrfs subvolume list /home
 +</code>
 +Note that this will display the link between the ''BTRFS_SNAPSHOT_ID'' and ''SNAPPER_SNAPSHOT_ID''.
 +
 +  * Note that if you are using snapper, you should delete snapshots using:
 +<code bash>
 +snapper -c home delete $SNAPPER_ID
 +</code>
 +You shouldn't delete the snapshot using ''btrfs subvolume delete'', as this will confuse Snapper. 
 +
 +===== Re-initialise qgroups =====
 +If your filesystem has just suffered an episode of catastrophic failure, you might need to re-initialise things. A Snapper rollback can cause it. 
 +<code bash>
 +for i in $(btrfs qgroup show /home | tail -n+3 | cut -d ' ' -f 1); do btrfs qgroup destroy $i /home; done
 +btrfs quota disable /home
 +btrfs quota enable /home
 +</code>
public/btrfs_snapshot_size.txt · Last modified: 2018/03/31 00:38 by 127.0.0.1