#VCP ## Use case Balancing datastore use across multiple Datastores inside a Storage DRS Cluster using storage vMotion either throughout operation or when migrating a VM to the Cluster. Storate DRS is taking account multiple Performance indicators. - Capacity - IO balance - Rule enforcement - affinity/anti-affinity like in [[vSphere - DRS.md]] - disks staying together - can be activated/deactivated in settings ## Requirements - Shared datastores on all participating hosts - Datastores of the same type (Flash, SAN) - storage vMotion capabilites through network. ## Rulesets - affinity/anti affinity - for redundancy sake e.g. "if one datastore goes down not all DCs should reside on a single Datastore" - keeping applications on the same datastore for latency - keeping VMDKs together - should be enabled usually, we do not want split up VMDKs but can be usefull especially for large VMDKs ## Threshold Storage DRS can be configured on multiple thresholds. Storage DRS will act upon these thresholds once exceeded. ### I/O I/O Metrics must be enabled for this. Storage A latency threshold can be configured for Storage DRS. Threshold is defined in ms of latency from the VM to storage. E.g. 20ms, meaning if a VM has a I/O latency of 20ms or more on a datastore, Storage DRS will try to migrate the VM to a datastore with less latency. ### Space threshold Storage DRS will look at the utilized space of a Datastore and will storage vMotion the VM off the datastore when the threshold is exceeded. Threshold can be configured either as Utilized space in % (e.g. migrate VMs off the datastore if the utilization exceeds 80%) or with minimum free space (e.g. 100GB must be unutilzed on the datastore, otherwise migrate VMs off the datastore.) ## Automation Automation policy is first set on a cluster level either to Fully automated or disabled and can then be overridden for each subcategory. ### Automation levels - Fully automated - Storage DRS will automatically balance the datastores based on the Indicators/Thresholds and defined rules. No user interaction required. - No automation (Manual mode) - Storage DRS will send recommendations based on Indicators/Thresholds and defined rules but not act without user input - Use cluster settings (subcategory) - use whatever is defined on the cluster level. ### Sub categories - Space balance automation - based on the space balance indicators and threshold - I/O balance automation level - based on I/O indicators and threshold - Rule enforcement automation level - based on defined affinity/anti-affinity rules. ## 🔗Resources