DataCore’s next release, SANsymphony-V10 PSP1, introduces many new and exciting features such as Sequential Storage which was covered in my last post. This post however, will focus on the new capabilities that relate to supporting storage segregation, isolation and tracking of storage resource utilization. Managed Service Providers and large IT organizations who manage internal Private Clouds are seeking more productive ways to cost-effectively centralize resources while providing their consumers (clients or departments) with what appears to be dedicated resources assigned to meet specific service level agreement (SLA) objectives.
A fundamental shift to a Quality of Service (QoS) model has already occurred, especially within the co-location, managed service and cloud service provider community. Storage is no longer simply deployed behind the primary offering (i.e. cloud offering, hosting environment, etc.), but rather provided as a service to clients directly from the provider’s central SAN. This same shift is also well underway within internal IT organizations who want to efficiently manage shared infrastructure resources via a private cloud model. They need a simple way to segregate, track and regulate their resources (including storage).
What Is Multitenancy?
Multi-tenancy simply means being able to service multiple independent consumers from a common centralized platform. The platform could be a virtual machine platform, mail hosting platform, web hosting platform, or in this case, a storage platform.
While not formally a part of the definition, there are implications attached to multi-tenancy such as isolation. Isolation, and reasonably so, should include at least end-to-end communication isolation so that consumers are not aware of one another (physically and logically). In terms of storage services provided by DataCore SANsymphony-V today, the isolation scheme takes the form of:
- Dedicated links between the provider’s distribution switches and the client’s cabinet (called cross-connects in MSP-speak) – handled by internal IT networking team or by the MSP
- Dedicated layer-2 segmentation (VLANs/Zones) for storage traffic across the switched network – handled by internal IT networking team or by the MSP
- Dedicated logical volumes only accessible by the client – handled by DataCore SANsymphony-V
- Dedicated storage pools formed from dedicated physical storage devices that are not shared in any way with other clients (not generally mandated unless client requires it due to specific regulatory compliance) – handled by DataCore SANsymphony-V
DataCore SANsymphony-V10 PSP1 – Extending Multi-tenancy Support
Together with the isolation schemes listed above, DataCore introduces new bandwidth isolation and resource tracking capabilities to ensure that no one client can impact the others and that resource consumption can be reported accurately. These capabilities specifically include:
- Host Groups are implemented to segregate Hosts (e.g., those in use by the Finance Department) and establish their own storage domains
- Storage Domains define a subset of resources
- Storage Policies are implemented within Storage Domains in order to regulate the Quality-of-Service (QoS) levels which define the bandwidth storage domains can consume (IOPS and/or data transfer rate)
- Chargeback implements resource utilization tracking which provides detailed reporting that can be used for billing purposes
Host groups form storage domains which contain the hosts and the storage resources where the policies are applied.
Hosts and Host Groups are defined within DataCore SANsymphony-V as they’ve always been, except storage policies impacting Quality of Service can now be applied to each Host Group as shown below:
The QoS storage policy settings take effect immediately for the designated host group. These settings prevent one client or host group from consuming all available bandwidth. This protects all clients from potentially erratic storage behavior during high utilization conditions.
The screenshots below show the storage activity through the system before and after DataCore QoS storage policies have been applied:
Chargeback can also be enabled from the QoS Settings screen allowing administrators to track and measure I/O statistics per consumer or host group. The following performance counters for the host group are added to the performance recording session:
- Total Bytes Written/sec
- Total Bytes Read/sec
- Total Reads/sec
- Total Writes/sec
- Total Bytes Provisioned
These metrics allow individual consumers to be billed for the resources utilized, whether it is bandwidth and/or storage consumption related. The screenshot below shows what a typical chargeback report looks like.
Also, the report data can be exported to several different formats for ease of viewing or importing into other back office systems.
Managed Service Providers and private clouds are continuing to drive a new model of storage service delivery. DataCore is ahead of the curve and well positioned to continue expanding the breadth and depth of these capabilities. Stay tuned for more coverage of the new features arriving with the release of SANsymphony-V10 PSP1 in November.