StorageOS Best Practices
Use an external Etcd cluster
StorageOS uses the
etcd distributed key-value store to store essential
cluster metadata and manage distributed configuration state. An embedded etcd
instance is included in the StorageOS container, but for production
environments and testing of production workloads, we recommend deploying an
external etcd cluster. For more details about, and an example of, how to run
etcd, see the External etcd Operations page.
It is highly recommended to use external etcd for cloud environments and place the etcd cluster on stable nodes. Placing the etcd on nodes that are recycled often might affect the normal operations of StorageOS.
Setup of storage on the hosts
We recommend creating a separate filesystem for StorageOS to mitigate the risk of filling the root filesystem on nodes. This has to be done for each node in the cluster.
Follow the managing host storage best practices page for more details.
StorageOS resource consumption depends on the workloads and the StorageOS features in use.
For production environments, it is recommended to test StorageOS using realistic workloads and tune resources accordingly.
The recommended minimum memory reservation for the StorageOS Pods is 235Mb. However it is recommended to prepare nodes so StorageOS can operate with at least with 1-2GB of memory. StorageOS frees memory when possible.
StorageOS Pods resource allocation will impact directly on the availability of volumes in case of eviction or resource limit triggered restart. It is recommended to not limit StorageOS Pods.
StorageOS implements a storage engine, therefore limiting CPU consumption might affect the I/O throughput of your volumes.
StorageOS API username/password
The API grants full access to StorageOS functionality, therefore we recommend that the default administrative password of ‘storageos’ is reset to something unique and strong.
You can change the default parameters by encoding the
apiPassword values (in base64) into the
To generate a unique password, a technique such as the following, which generates a pseudo-random 24 character string, may be used:
# Generate strong password PASSWORD=$(cat -e /dev/urandom | tr -dc '[email protected]#$%^&*()_+~' | fold -w 24 | head -n 1) # Convert password to base64 representation for embedding in a K8S secret BASE64PASSWORD=$(echo -n $PASSWORD | base64)
Note that the Kubernetes secret containing a strong password must be created before bootstrapping the cluster. Multiple installation procedures use this Secret to create a StorageOS account when the cluster first starts.
StorageOS Pod placement
StorageOS must run on all nodes that will contribute storage capacity to the cluster or that will host Pods which use StorageOS volumes. For production environments, it is recommended to avoid placing StorageOS Pods on Master nodes.
StorageOS is deployed with a DaemonSet controller, and therefore tolerates the standard unschedulable (:NoSchedule) action. If that is the only taint placed on master or cordoned nodes StorageOS pods might start on them (see the Kubernetes docs for more details). To avoid scheduling StorageOS pods on master nodes, you can add an arbitrary taint to them for which the StorageOS DaemonSet won’t have a toleration.
Dedicated instance groups
Cloud environments give users the ability to quickly scale the number of nodes in a cluster in response to their needs. Because of the ephemeral nature of the cloud, StorageOS recommends setting conservative downscaling policies.
For production clusters, it recommended to use dedicated instance groups for Stateful applications that allow the user to set different scaling policies and define StorageOS pools based on node selectors to collocate volumes.
Losing a few nodes at the same time could cause the loss of data even when volume replicas are being used.
StorageOS exposes ports to operate. It is recommended that the ports are not accessible from outside the scope of your cluster.
StorageOS in Docker EE
StorageOS does not support running on Swarm nodes nor on mixed (Kubernetes and Swarm) nodes. StorageOS volumes have to be provisioned and used from Kubernetes nodes.