Hi All,
Earlier this month I had sent out a lpc micro conference proposal for
file system shrink. It sounds like the talk is of interest, but folks
recommended I forward the discussion to fsdevel for more feed back.
Below is the abstract for the talk:
File system shrink allows a file system to be reduced in size by some
specified size blocks as long as the file system has enough unallocated
space to do so. This operation is currently unsupported in xfs. Though
a file system can be backed up and recreated in smaller sizes, this is
not functionally the same as an in place resize. Implementing this
feature is costly in terms of developer time and resources, so it is
important to consider the motivations to implement this feature. This
talk would aim to discuss any user stories for this feature. What are
the possible cases for a user needing to shrink the file system after
creation, and by how much? Can these requirements be satisfied with a
simpler mkfs option to backup an existing file system into a new but
smaller filesystem? In the cases of creating a rootfs, will a protofile
suffice? If the shrink feature is needed, we should further discuss the
APIs that users would need.
Beyond the user stories, it is also worth discussing implementation
challenges. Reflink and parent pointers can assist in facilitating
shrink operations, but is it reasonable to make them requirements for
shrink? Gathering feedback and addressing these challenges will help
guide future development efforts for this feature.
Comments and feedback are appreciated!
Thanks!
Allison
