csi | Container Storage Interfaces for CNCF | Continuous Deployment library

It has nothing to do with the different containers. Whichever process is crashing is just broken, the code has a bug where it registers the same flag twice which isn't allowed.

I managed to fix my problem by adding the pvc first instead of using volumeClaimTemplates

Can a new PV be created so it's 1:1 replicated between 2+ nodes on the cluster?

None of the standard volume types are replicated at all. If you can use a volume type that supports ReadWriteMany access (most readily NFS) then multiple pods can use it simultaneously, but you would have to run the matching NFS server.

Of the volume types you reference:

• hostPath is a directory on the node the pod happens to be running on. It's not a directory on any specific node, so if the pod gets recreated on a different node, it will refer to the same directory but on the new node, presumably with different content. Aside from basic test scenarios I'm not sure when a hostPath PersistentVolume would be useful.

• local is a directory on a specific node, or at least following a node-affinity constraint. Kubernetes knows that not all storage can be mounted on every node, so this automatically constrains the pod to run on the node that has the directory (assuming the node still exists).

• csi is an extremely generic extension mechanism, so that you can run storage drivers that aren't on the list you link to. There are some features that might be better supported by the CSI version of a storage backend than the in-tree version. (I'm familiar with AWS: the EBS CSI driver supports snapshots and resizing; the EFS CSI driver can dynamically provision NFS directories.)

In the specific case of a local test cluster (say, using kind) using a local volume will constrain pods to run on the node that has the data, which is more robust than using a hostPath volume. It won't replicate the data, though, so if the node with the data is deleted, the data goes away with it.

add !important attribute

As already discussed in the comments the Ingress Controller will be created in the ingress-nginx namespace instead of the kube-system namespace. Other than that the rest of the tutorial should work as expected.

It’s a daemonset.

kubectl -n kube-system edit ds/efs-csi-node

I looks like there is open feature request on kubernetes-sigs/aws-ebs-csi-driver repo but no progress on this. So I guess that it is not supported at the moment but you can monitor the issue for updates.

You can use opencv API directly.

Instead of creating a PiCamera object like:

AFAIK, the answer is No. However, I am citing a following explanation from the source that may be helpful for you:

Consider the way Ceph stores data... each RBD is striped into chunks (RADOS objects with 4MB size by default); the chunks are distributed among the OSDs with the configured number of replicates (probably two in your case since you use 2 OSD hosts). RBD uses thin provisioning, so chunks are allocated upon first write access. If an RBD is deleted all of its chunks are deleted on the corresponding OSDs. If you want to recover a deleted RBD, you need to recover all individual chunks. Whether this is possible depends on your filesystem and whether the space of a former chunk is already assigned to other RADOS objects. The RADOS object names are composed of the RBD name and the offset position of the chunk, so if an undelete mechanism exists for the OSDs' filesystem, you have to be able to recover file by their filename, otherwise you might end up mixing the content of various deleted RBDs. Due to the thin provisioning there might be some chunks missing (e.g. never allocated before).

However, there is still some hope. The Ceph book called Mastering Ceph has given some hints to recover the data as following:

there are tools that can search through the OSD data structure, find the object files relating to RBDs, and then assemble these objects back into a disk image, resembling the original RBD image.

May be you need to find the right tool in Ceph source code.