PLEASE NOTE: This document applies to an unreleased version of Rook. It is strongly recommended that you only use official releases of Rook, as unreleased versions are subject to changes and incompatibilities that will not be supported in the official releases.
If you are using an official release version of Rook, you should refer to the documentation for your specific version.Documentation for other releases can be found by using the version selector in the bottom left of any doc page.
EdgeFS iSCSI Target CRD
Rook allows creation and customization of High Performance iSCSI Target compatible services through the custom resource definitions (CRDs). The following settings are available for customization of iSCSI Target services.
apiVersion: edgefs.rook.io/v1alpha1 kind: ISCSI metadata: name: iscsi01 namespace: rook-edgefs spec: placement: # nodeAffinity: # requiredDuringSchedulingIgnoredDuringExecution: # nodeSelectorTerms: # - matchExpressions: # - key: role # operator: In # values: # - iscsi-node # tolerations: # - key: iscsi-node # operator: Exists # podAffinity: # podAntiAffinity: resources: # limits: # cpu: "500m" # memory: "1024Mi" # requests: # cpu: "500m" # memory: "1024Mi"
name: The name of the iSCSI target service to create, which must match existing EdgeFS service.
namespace: The namespace of the Rook cluster where the iSCSI Target service is created.
targetName: The name for iSCSI target name. Default is iqn.2018-11.edgefs.io.
targetParams: If specified, then some of iSCSI target protocol parameters can be overridden.
MaxRecvDataSegmentLength: Value in range value range 512..16777215. Default is 524288.
DefaultTime2Retain: Value in range 0..3600. Default is 60.
DefaultTime2Wait: Value in range 0..3600. Default is 30.
FirstBurstLength: Value in range 512..16777215. Default is 524288.
MaxBurstLength: Value in range 512..16777215. Default is 1048576.
MaxQueueCmd: Value in range 1..128. Default is 64.
placement: The iSCSI pods can be given standard Kubernetes placement restrictions with
podAntiAffinitysimilar to placement defined for daemons configured by the cluster CRD.
resources: Set resource requests/limits for the iSCSI pods, see Resource Requirements/Limits.
Setting up EdgeFS namespace and tenant
For more detailed instructions please refer to EdgeFS Wiki.
Simple procedure to get things initialized and configured:
Setting up FlexHash and Site root object
Before new local namespace (or local site) can be used, it has to be initialized with FlexHash and special purpose root object.
FlexHash consists of dynamically discovered configuration and checkpoint of accepted distribution table. FlexHash is responsible for I/O direction and plays important role in dynamic load balancing logic. It defines so-called Negotiating Groups (typically across zoned 8-24 disks) and final table distribution across all the participating components, e.g. data nodes, service gateways and tools.
Root object holds system information and table of namespaces registered to a local site. Root object is always local and never shared between the sites.
To initialize system and prepare logical definitions, login to the toolbox as shown in this example:
kubectl get po --all-namespaces | grep edgefs-mgr kubectl exec -it -n rook-edgefs rook-edgefs-mgr-6cb9598469-czr7p -- env COLUMNS=$COLUMNS LINES=$LINES TERM=linux toolbox
Assumption at this point is that nodes are all configured and can be seen via the following command:
efscli system status
- Initialize cluster
Verify that HW (or better say emulated in this case) configuration look normal and accept it
efscli system init
At this point new dynamically discovered configuration checkpoint will be created at $NEDGE_HOME/var/run/flexhash-checkpoint.json This will also create system “root” object, holding Site’s Namespace. Namespace may consist of more then single region.
- Create new local namespace (or we also call it “Region” or “Segment”)
efscli cluster create Hawaii
- Create logical tenants of cluster namespace “Hawaii”, also buckets if needed
efscli tenant create Hawaii/Cola efscli bucket create Hawaii/Cola/bk1 efscli tenant create Hawaii/Pepsi efscli bucket create Hawaii/Pepsi/bk1
Now cluster is setup, services can be now created.
- Create iSCSI Target services objects for tenants
efscli service create iscsi iscCola efscli service serve iscCola Hawaii/Cola/bk1/lun1 X-volsize=10G,ccow-chunkmap-chunk-size=16384 efscli service serve iscCola Hawaii/Cola/bk1/lun2 X-volsize=20G,ccow-chunkmap-chunk-size=131072 efscli service create iscsi iscPepsi efscli service serve iscPepsi Hawaii/Pepsi/bk1/lun1 X-volsize=20G
- Create ISCSI CRDs
apiVersion: edgefs.rook.io/v1alpha1 kind: ISCSI metadata: name: iscCola namespace: rook-edgefs
apiVersion: edgefs.rook.io/v1alpha1 kind: ISCSI metadata: name: iscPepsi namespace: rook-edgefs
At this point two iSCSI Target services should be available and listening on default port 3260.