Tuesday, September 11, 2012
In vSphere
5 VMware includes Storage Distributed Resource Scheduler. Storage DRS perform
automatic load balancing if a disk becomes overloaded and automatically load
balance IO activity. Storage DRS decrease operational efforts associated with
the provisioning of VM and monitoring of the storage environment.
In vSphere
5.0 VMware comes up with a new object in vCenter called DataStore
Cluster. DataStore Cluster forms the baseline of
Storage DRS. Similar to cluster of host, a DataStore Cluster aggregate storage
resources. Storage DRS gets enabled by own once we create Data Store Cluster.
Once we have Storage DRS enabled, the datastore cluster becomes a load
– balancing domain. We can have VMFS – 3 & VMFS 5 member of a DataStore
Cluster but mixing of NFS & VMFS is not supported.
Storage
DRS provides initial placement and ongoing balancing recommendations based on
space & I/O Capacity. During VM provisioning, a data store cluster
can be selected as target destination for VM or Virtual Disk. Ongoing balancing
recommendations are made once data stores in a cluster exceeds configured space
utilization or I/O latency thresholds.
Similar to
HOSTS based DRS, Affinity rules can be configured in Storage DRS. Storage DRS
offers three types of affinity rules
VMDK Anti
– Affinity : Virtual Disks of a VM with multiple virtual disks are placed on
different data stores.
VMDK
Affinity : Virtual disks are kept together on the same data store
VM Anti –
Affinity : Two specified virtual machines, including associated disks are
placed on different datastores.
Storage
DRS also offers Datastore Maintenance Mode, which automatically evacuates all
VM & Virtual Disks from selecting datastores.
