Add dm.blocksize option that you can use with --storage-opt to set a
specific blocksize for the thin provisioning pool.
Also change the default dm-thin-pool blocksize from 64K to 512K. This
strikes a balance between the desire to have smaller blocksize given
docker's use of snapshots versus the desire to have more performance
that comes with using a larger blocksize. But if very small files will
be used on average the user is encouraged to override this default.
Docker-DCO-1.1-Signed-off-by: Mike Snitzer <snitzer@redhat.com> (github: snitm)
createPool() and reloadPool() should be consistent with the thin-pool
table params they use.
Since createPool() specifies '1 skip_block_zeroing' reloadPool() should
too. Otherwise, if the pool is reloaded (as is done when resizing
loopback devices) block zeroing will be enabled after the reload
completes.
Docker-DCO-1.1-Signed-off-by: Mike Snitzer <snitzer@redhat.com> (github: snitm)
If we can't even get the current device mapper driver version, then
we cleanly fail the devmapper driver as not supported and fall back
on the next one.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Instead of globally keeping track of the free device ids we just
start from 0 each run and handle EEXIST error and try the next one.
This way we don't need any global state for the device ids, which
means we can read device metadata lazily. This is important for
multi-process use of the backend.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
This moves the EBUSY detection to devmapper.go, and then returns
a real ErrBusy that deviceset uses.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
