Adds commands to both replace an OSD disk, and refresh (reimport) an
existing OSD disk on a new node. This handles the cases where an OSD
disk should be replaced (either due to upgrades or failures) or where a
node is rebuilt in-place and an existing OSD must be re-imported to it.
This should avoid the need to do a full remove/add sequence for either
case.
Also cleans up some aspects of OSD removal that are identical between
methods (e.g. using safe-to-destroy and sleeping after stopping) and
fixes a bug if an OSD does not truly exist when the daemon starts up.
With the OSD LVM information stored in Zookeeper, we can use this to
determine the actual block device to zap rather than relying on runtime
determination and guestimation.
Ensures that information like the FSIDs and the OSD LVM volume are
stored in Zookeeper at creation time and updated at daemon start time
(to ensure the data is populated at least once, or if the /dev/sdX
path changes).
This will allow safer operation of OSD removals and the potential
implementation of re-activation after node replacements.
Allows specifying blockdevs in the OSD and OSD-DB addition commands as
detect strings rather than actual block device paths. This provides
greater flexibility for automation with pvcbootstrapd (which originates
the concept of detect strings) and in general usage as well.
Refactors some of the code in VXNetworkInterface to handle MTUs in a
more streamlined fashion. Also fixes a bug whereby bridge client
networks were being explicitly given the cluster dev MTU which might not
be correct. Now adds support for this option explicitly in the configs,
and defaults to 1500 for safety (the standard Ethernet MTU).
Addresses #144
Remove two superfluous synchronization steps which are not needed here,
since the exclusive lock handles that situation anyways.
Still does not fix the weird flush->unflush lock timeout bug, but is
better worked-around now due to the cancelling of the other wait freeing
this up and continuing.
Make the block on stage C only wait for 900 seconds (15 minutes) to
prevent indefinite blocking.
The issue comes if a VM is being received, and the current unflush is
cancelled for a flush. When this happens, this lock acquisition seems to
block for no obvious reason, and no other changes seem to affect it.
This is certainly some sort of locking bug within Kazoo but I can't
diagnose it as-is. Leave a TODO to look into this again in the future.
Rather than using a cumbersome and overly complex ping-pong of read and
write locks, instead move to a much simpler process using exclusive
locks.
Describing the process in ASCII or narrative is cumbersome, but the
process ping-pongs via a set of exclusive locks and wait timers, so that
the two sides are able to synchronize via blocking the exclusive lock.
The end result is a much more streamlined migration (takes about half
the time all things considered) which should be less error-prone.
The previous implementation did not work with /dev/nvme devices or any
/dev/disk/by-* devices due to some logical failures in the partition
naming scheme, so fix these, and be explicit about what is supported in
the PVC CLI command output.
The 'echo | gdisk' implementation of partition creation also did not
work due to limitations of subprocess.run; instead, use sgdisk which
allows these commands to be written out explicitly and is included in
the same package as gdisk.
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
Joshua Boniface