The default of 0.05 (5%) is likely ideal in the initial implementation,
but allow this to be set explicitly for maximum flexibility in
space-constrained or performance-critical use-cases.
Adds in three parts:
1. Create an API endpoint to create OSD DB volume groups on a device.
Passed through to the node via the same command pipeline as
creating/removing OSDs, and creates a volume group with a fixed name
(osd-db).
2. Adds API support for specifying whether or not to use this DB volume
group when creating a new OSD via the "ext_db" flag. Naming and sizing
is fixed for simplicity and based on Ceph recommendations (5% of OSD
size). The Zookeeper schema tracks the block device to use during
removal.
3. Adds CLI support for the new and modified API endpoints, as well as
displaying the block device and DB block device in the OSD list.
While I debated supporting adding a DB device to an existing OSD, in
practice this ended up being a very complex operation involving stopping
the OSD and setting some options, so this is not supported; this can be
specified during OSD creation only.
Closes#142
Ensures that a VM won't:
(a) Have provisioned more RAM than there is available on a given node.
Due to memory overprovisioning, this is simply a "is the VM memory count
more than the node count", and doesn't factor in free or used memory on
a node, total cluster usage, etc. So if a node has 64GB total RAM, the
VM limit is 64GB. It is up to an administrator to ensure sanity *below*
that value.
(b) Have provisioned more vCPUs than there are CPU cores on the node,
minus 2 to account for hypervisor/storage processes. Will ensure there
is no severe CPU contention caused by a single VM having more vCPUs than
there are actual execution threads available.
Closes#139
Adds a new API endpoint to support hot attach/detach of devices, and the
corresponding client-side logic to use this endpoint when doing VM
network/storage add/remove actions.
The live attach is now the default behaviour for these types of
additions and removals, and can be disabled if needed.
Closes#141
This branch commit refactors the pvcnoded component to better adhere to
good programming practices. The previous Daemon.py was a massive file
which contained almost 2000 lines of direct, root-level code which was
directly imported. Not only was this poor practice, but this resulted
in a nigh-unmaintainable file which was hard even for me to understand.
This refactoring splits a large section of the code from Daemon.py into
separate small modules and functions in the `util/` directory. This will
hopefully make most of the functionality easy to find and modify without
having to dig through a single large file.
Further the existing subcomponents have been moved to the `objects/`
directory which clearly separates them.
Finally, the Daemon.py code has mostly been moved into a function,
`entrypoint()`, which is then called from the `pvcnoded.py` stub.
An additional item is that most format strings have been replaced by
f-strings to make use of the Python 3.6 features in Daemon.py and the
utility files.
This should be managed in ceph.conf with the `rbd default
features` configuration option instead, and thus can be tailored to the
underlying OS version.
If this isn't, the resize will be interpreted as a MB value and result
in an absurdly big volume instead. This is the same consistency
validation that occurs on add.
Convert from human to bytes, then to megabytes and always pass this to
the RBD command. This ensures consistency regardless of what is actually
passed by the user.
Before, "-y"/"--yes" only confirmed the reboot portion. Instead, modify
this to confirm both the diff portion and the restart portion, and add
separate flags to bypass one or the other independently, ensuring the
administrator has lots of flexibility. UNSAFE mode implies "-y" so both
would be auto-confirmed if that option is set.
Joshua Boniface