Currently we would create a new disk and mount this into the LCOW UVM for every container but there
are certain scenarios where we'd rather just mount a single disk and then have every container share this one
storage space instead of every container having it's own xGB of space to play around with.
This is accomplished by just making a symlink to the disk that we'd like to share and then
using ref counting later on down the stack in hcsshim if we see that we've already mounted this
disk.
Signed-off-by: Daniel Canter <dcanter@microsoft.com>
For LCOW currently we copy (or create) the scratch.vhdx for every single snapshot
so there ends up being a sandbox.vhdx in every directory seemingly unnecessarily. With the default scratch
size of 20GB the size on disk is about 17MB so there's a 17MB overhead per layer plus the time to copy the
file with every snapshot. Only the final sandbox.vhdx is actually used so this would be a nice little
optimization.
For WCOW we essentially do the exact same except copy the blank vhdx from the base layer.
Signed-off-by: Daniel Canter <dcanter@microsoft.com>
Previously there wwasn't a way to pass any labels to snapshotters as the wrapper
around WithNewSnapshot didn't have a parm to pass them in.
Signed-off-by: Daniel Canter <dcanter@microsoft.com>
This also refactors the lcow and windows
snapshotters to use go-winio's utility functions for checking the
filesystem type.
Signed-off-by: Eric Hotinger <ehotinger@gmail.com>
Implements the Windows lcow differ/snapshotter responsible for managing
the creation and lifetime of lcow containers on Windows.
Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>
