command.
WARNING: Qgroup is not stable yet and will impact performance in current mainline
-kernel (v3.14 so far).
+kernel (v4.14).
QGROUP
------
attached to subvolumes. The size limits are set per qgroup and apply when any
limit is reached in tree that contains a given subvolume.
-The limit sare separated between shared and exclusive and reflect the extent
+The limits are separated between shared and exclusive and reflect the extent
ownership. For example a fresh snapshot shares almost all the blocks with the
original subvolume, new writes to either subvolume will raise towards the
exclusive limit.
Create a subvolume quota group.
+
For the '0/<subvolume id>' qgroup, a qgroup can be created even before the
-subvolume created.
+subvolume is created.
*destroy* <qgroupid> <path>::
Destroy a qgroup.
+
-If a qgroup is no isolated,which means it is a parent or child qgroup, it
-can't be destroyed.
+If a qgroup is not isolated, meaning it is a parent or child qgroup, then it
+can only be destroyed after the relationship is removed.
*limit* [options] <size>|none [<qgroupid>] <path>::
Limit the size of a qgroup to <size> or no limit in the btrfs filesystem
If no prefix is given, use ascending order by default.
+
If multiple <attr>s is given, use comma to separate.
++
+--sync::::
+To retrieve information after updating the state of qgroups,
+force sync of the filesystem identified by <path> before getting information.
EXIT STATUS
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