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vStart 1000m for Enterprise Virtualization using Hyper-V – Reference Architecture
Dell Inc. 20
6.6.5 Drive Types
Dell Compellent storage enclosures feature 6 Gb SAS interconnects, so organizations can scale up and
out with ease. Administrators can mix SSD and SAS drives in the same system, as well as SAS drives with
the same form factor (but different speeds and capacities) in the same storage enclosure.
The Dell vStart for Enterprise Virtualization base solutions are based upon the number of compute
nodes. As an example the 16 blade configuration utilizes three 24 bay 2.5‖ SAS drive enclosures and
the fourth enclosure uses the one bay 3.5‖ SAS drives. The 2.5‖ drives selected are 300 GB 15K RPM SAS
and the 3.5‖ drives are 2TB 7K RPM SAS. This provides a balance of space and IOPS.
Compellent Fluid Data storage dynamically moves data to the optimal tier based on actual usage. The
most active blocks reside on high-performance SSD, FC, or SAS drives, while infrequently accessed data
migrates to lower-cost, high-capacity SAS or SATA drives.
In the 16 blade configuration example, three enclosures are configured with 15K 300GB 2.5‖ SAS drives
and are designated as Tier-1. One enclosure is configured with 7K 1TB 2.5‖ SAS drives and is designated
as Tier-3. Compellent Storage Center automatically configures RAID levels for these tiers and
automatically moves the data between the tiers based on access patterns. For more details refer to the
Automated Tiered Storage web page.
6.6.6 RAID Array Design
Dell Compellent Series 40 supports RAID 5, 6 and 10. The Compellent Storage Center will dynamically
set up RAID based upon the demand of the storage.
6.6.7 Cluster Shared Volumes
Cluster Shared Volumes (CSV) is the storage volumes of choice for Hyper-V clusters. Developed by
Microsoft exclusively for Hyper-V, they enable multiple Hyper-V cluster nodes to simultaneously access
VMs. The CSVs are used throughout the vStart for Enterprise Cloud solution for both the fabric and
fabric management servers.
6.6.7.1 CSV Limits
The below limitations are actually imposed by the NTFS file system and are inherited by CSV.
Table 4: CSV Limits
CSV parameter
Limitation
Maximum Volume Size
256 TB
Maximum # Partitions
128
Directory Structure
Unrestricted
Maximum Files per CSV
4+ Billion
Maximum VMs per CSV
Unrestricted