Managing Storage Capacity with OpenShift Data Foundation Flashcards
(97 cards)
1
Q
What is the main objective of configuring storage quotas and permissions in OpenShift?
A
Configure and verify quotas and permissions for Red Hat OpenShift Data Foundation cluster storage
2
Q
What technique is used for managing access to resources in Red Hat OpenShift?
A
Role-based access control (RBAC)
3
Q
What does RBAC determine in the context of OpenShift?
A
Whether a user can perform certain actions within the cluster or project
4
Q
How does RBAC apply to OpenShift Data Foundation?
A
It controls access to storage classes and clusters
5
Q
What are storage cluster permissions used for?
A
Managing storage volume access
6
Q
How can cluster administrators restrict access to storage classes?
A
By using RBAC to allow or deny access
7
Q
What is an example of how access can be restricted using RBAC?
A
Limiting storage types that development applications can access
8
Q
What resources manage the RBAC authorization process in OpenShift?
A
Rules, Roles, Bindings
9
Q
What are rules in the context of RBAC?
A
Sets of permitted verbs on a group of objects
10
Q
What is a role in RBAC?
A
A set of rules that can be associated with users and groups
11
Q
What are bindings in RBAC?
A
Assignments of users or groups to a role
12
Q
How does RBAC control storage on the cluster and project level?
A
By configuring default settings for cluster storage pools and managing PVCs
13
Q
What are the two groups of roles and bindings defined by OpenShift?
A
- Cluster RBAC
- Local RBAC
14
Q
What does Cluster RBAC refer to?
A
Roles and bindings that apply across all projects
15
Q
What does Local RBAC refer to?
A
Roles and bindings scoped to a given project
16
Q
True or False: Local role bindings can only reference local roles.
A
False
17
Q
Fill in the blank: RBAC controls storage on the _______ and _______ level.
A
[cluster] and [project]
18
Q
What command is used to add a cluster role to a user?
A
oc adm policy add-cluster-role-to-user cluster-role username
19
Q
What command is used to add a role to a user for a specific project?
A
oc adm policy add-role-to-user role username -n project
20
Q
What command determines if a user can execute an action on a resource?
A
oc adm policy who-can verb resource
21
Q
List some verbs that can be used in the ‘who-can’ command.
A
- get
- list
- create
- update
- delete
- deletecollection
- watch
22
Q
What is the admin cluster role capable of?
A
Manage all project resources and grant access to other users
23
Q
What access does the basic-user cluster role provide?
A
Read access to the project
24
Q
What capabilities does the cluster-admin role provide?
A
Superuser access to cluster resources, full control of all projects
25
What can users with the edit role do?
Create, change, or delete common application resources from the project
26
What is the purpose of limit ranges and resource quotas?
Create restrictions on cluster resources such as CPU, memory, and storage
27
What are the benefits of creating resource quotas and limit ranges?
* Provide practical restraints for storage
* Ensure applications do not outgrow data volume
* Indicate unusual storage growth
* Control billing on third-party cloud storage
28
What are the two types of resource quotas OpenShift provides?
* Single project resource quota
* Shared cluster resource quota
29
What does the requests.storage resource quota represent?
The sum of storage requests across all PVCs cannot exceed this value
30
What command is used to view the resource quotas for a project?
oc get resourcequotas
31
What is the purpose of the ClusterResourceQuota?
Set resource quotas across projects to enforce a baseline storage allocation
32
What does the LimitRange object define?
Limits for workloads within the namespace, including min, max, and default values
33
What is the purpose of the maxLimitRequestRatio key in limit ranges?
Controls the relationship between limits and requests
34
True or False: Users with the edit role can manage access permissions to the project.
False
35
Fill in the blank: Users with the _______ role can create projects.
self-provisioner
36
What does the ephemeral-storage resource quota limit?
The sum of ephemeral storage requests across all pods in a non-terminal state
37
What command would you use to list the AppliedClusterResourceQuota objects?
oc describe appliedclusterresourcequotas
38
What is the default limit in limit ranges used for?
Specify default limits for workloads
39
What is the main objective of extending application storage?
Detect when a storage volume is close to full and expand the volume size without disrupting an application.
40
What feature does OpenShift Data Foundation provide for persistent volume claims?
Persistent volume claim (PVC) expansion for flexible management of persistent storage resources.
41
Which types of PVCs can be expanded?
* PVC with ReadWriteOnce or ReadWriteMany access based on Ceph File System with the Filesystem volume mode
* PVC with ReadWriteOnce access based on Ceph RADOS Block Devices with the Filesystem volume mode
* PVC with ReadWriteOnce access based on Ceph RADOS Block Devices with the Block volume mode
* PVC with ReadWriteOncePod based on Ceph File System or Network File System with the Filesystem volume mode
* PVC with ReadWriteOncePod access based on Ceph RADOS Block Devices with the Filesystem volume mode
42
What scenarios does PVC expansion not support?
* Recovering from failure when expanding volumes
* PVC shrinking
43
What attribute must be set to true for a storage class to allow PVC expansion?
allowVolumeExpansion attribute
44
How can you check if a storage class enables volume expansion?
From the ALLOWVOLUMEEXPANSION field.
45
What command is used to check storage classes in OpenShift?
oc get sc
46
What change triggers a Resizing event for a PVC?
Modifying the storage resource request.
47
What is the command to edit a PVC resource?
oc edit pvc/
48
What command can be used as an alternative to edit a PVC for resizing?
oc patch pvc/
49
What is the expected outcome after a successful PVC resize?
The Capacity field is set to the new value.
50
What does the Events section of a PVC describe after resizing?
The log of the resize procedure.
51
What event indicates that a file system resize is required for a PVC based on Ceph RADOS Block Devices?
FileSystemResizeRequired
52
What does the Condition type FileSystemResizePending indicate?
Waiting for user to (re-)start a pod to finish the file system resize.
53
Fill in the blank: PVC expansion is not supported for _______.
[OSD, MON, and encrypted PVCs]
54
What command is used to describe a PVC in OpenShift?
oc describe pvc/
55
What is the objective of reclaiming space from the OpenShift Data Foundation cluster?
Reclaim space and remove orphaned volumes from Red Hat OpenShift Data Foundation cluster storage.
56
Does OpenShift automatically remove volumes and snapshots with a Retain reclaim policy?
No, OpenShift does not automatically remove them.
57
What can lead to a storage-full scenario in the OpenShift Data Foundation?
Orphaned volumes can fill the storage cluster.
58
What is the first step to identify orphaned volumes?
Compare the volumes in OpenShift with the volumes in OpenShift Data Foundation.
59
How does Ceph use thin provisioning for volumes?
Ceph reserves the PV space rather than making it available when files are removed.
60
What tools does OpenShift Data Foundation provide to reclaim space from volumes?
OpenShift Data Foundation provides tools to reclaim space from volumes.
61
What command is executed on file-system volumes to reclaim space?
fstrim
62
What command is executed on volumes that are not mounted to any pod?
rbd sparsify
63
What kind of job can be used to manually reclaim space from a volume?
ReclaimSpaceJob CR
64
What is the maximum number of retries before a reclaim operation fails?
10
65
What command can you use to check the status of reclaim space jobs?
oc get reclaimspacejobs
66
What is the purpose of a ReclaimSpaceCronJob?
To reclaim space from a volume based on a given schedule.
67
What is the default schedule value for reclaim space operations if not specified?
@weekly
68
What annotation is used to enable automatic space reclamation on a PVC?
reclaimspace.csiaddons.openshift.io/schedule
69
What must you do to enable existing disks on nodes for storage?
Create a LocalVolume object.
70
What is the maximum number of storage devices allowed per node?
Nine
71
What does the local storage operator do when discovering disks?
Creates PVs that the Rook-Ceph operator uses.
72
What is the command to list the disks available on a node?
oc get localvolumediscoveryresult
73
What is the purpose of the LocalVolumeDiscoveryResult object?
Contains the set of disks discovered for a node.
74
What is required for a successful deployment in terms of disk types?
The new disks must be the same size and type as those used during deployment.
75
What happens if flexible scaling is enabled during deployment?
It cannot be enabled or disabled later.
76
How can you enable the reclaim space operation every week on a PVC?
Use the command: oc annotate pvc data reclaimspace.csiaddons.openshift.io/schedule='0 0 * * 0'
77
What is the command used to check the status of reclaim space cron jobs?
oc get reclaimspacecronjobs
78
What is the result of applying a reclaim space annotation to a namespace?
OpenShift reclaims space automatically for all PVCs in the namespace.
79
What must you do to apply a reclaim space annotation to PVCs created before the annotation?
Restart the CSI add-ons controller.
80
What is the command to create a LocalVolume object?
apiVersion: local.storage.openshift.io/v1
81
What is the status of a disk that is available in the LocalVolumeDiscoveryResult object?
Available
82
Fill in the blank: OpenShift Data Foundation enables you to scale by adding disks to the storage nodes or by adding _______.
storage nodes
83
What command is used to filter the PVs created for a node?
oc get pv -l kubernetes.io/hostname=worker01
84
What does the status 'Available' indicate for a PV?
The Rook-Ceph operator can use this PV as a disk for the internal Ceph storage.
85
How do you add available disks to the cluster?
Set the spec.storageDeviceSets.count value on the storagecluster/ocs-storagecluster object.
86
What should the count value be set to when flexible scaling is not enabled?
Increment the count by one for each set of three disks.
87
What is the purpose of the apiVersion field in a StorageCluster object?
Defines the API version for the storage cluster configuration.
88
What indicates that the disks are added successfully after changing the count?
Ceph OSD pods are created to provide extended storage.
89
How can you verify that the OSD pods are running?
List the pods with the app=rook-ceph-osd label.
90
What happens to the status of PVs after OSD pods are running?
The status changes from Available to Bound.
91
What is the required node addition strategy for deployments with three failure domains?
Add nodes in multiples of 3, each in different failure domains.
92
What command is used to label new compute nodes for OpenShift Data Foundation?
oc label nodes -l node-role.kubernetes.io/worker= cluster.ocs.openshift.io/openshift-storage=
93
What do the LocalVolumeDiscovery and LocalVolumeSet objects use in the nodeSelector field?
The OpenShift Data Foundation label.
94
What command can be used to inspect the LocalVolumeSet object?
oc get localvolumesets/lso-volumeset -o custom-columns='"NAME:metadata.name,STORAGECLASS:spec.storageClassName,PROVISIONED:status.totalProvisionedDeviceCount,VOLUME_MODE:spec.volumeMode"' -n openshift-local-storage
95
What should be verified in the openshift-storage namespace after adding nodes?
At least the following pods should display a status of Running: csi-cephfsplugin-* and csi-rbdplugin-*.
96
Where can you confirm the new capacity of the OpenShift Data Foundation cluster?
Go to Storage → Data Foundation in the OpenShift web console.
97
Fill in the blank: To add available disks to the cluster, set the spec.storageDeviceSets.count value on the _______.
storagecluster/ocs-storagecluster object
