Snapshots / Backups (Differential & Full Clones)
SANsymphony supports instant point-in-time snapshots along with full copy clones. You may periodically update snapshots to a later point in time with just the changed blocks that transpired after the last snapshot. You may also use snapshots to restore the source volume via the source update option. Snapshots are readable and writeable. SANsymphony uses copy-on-first-write technology as well as thin provisioning to significantly reduce the space taken up by incremental snapshots. The snapshot is available immediately upon request and may be triggered by VSS-compatible applications, VMware vCenter and PowerShell scripts. DataCore works with popular 3rd party backup products, including CommVault, to simplify end-to-end data protection and ensure rapid data recovery at a granular level.
Continuous data protection may be selected for virtual disks to restore the state of the virtual disks before an undesirable change (ransomware, user errors and virus, database corruption, for example). The software will log and timestamp every update to the virtual disks in a rolling buffer covering up to the last 14 days (depending on configuration parameters and available disk space). The state of the virtual disks may later be recovered to a desired point in time within the 14 day period.
SANsymphony supports software mirroring and striping across physical disks behind each DataCore node. It can also rely on RAID protection from back-end RAID subsystems and disk controllers.
DataCore offers an enterprise-class “zero downtime, zero touch” high availability storage solution that prevents equipment and site outages from interrupting critical information flow. The cost-disruptive software innovations proven in over 30,000 global deployments provide simultaneous access to active copies mirrored between physically-separate locations, making it the centerpiece for business continuity.
DataCore enables application and/or server clustering technologies in campus and metro-wide configurations (stretch clusters) to continuously update and retrieve data, even with the loss of an entire site. In contrast with competing alternatives, no manual intervention or scripting is needed for failover, resynchronization or failback; everything is automated. Customers report a 100% reduction in storage-related planned and unplanned downtime; many for more than 8 years. The software synchronously mirrors virtual disks in lock step across two DataCore nodes. Separations up to 100 kilometers (~60 miles) are typically achieved using dedicated high-bandwidth optical routes across Metropolitan Area Networks (MANs). Longer distances may be achieved for more latency-tolerant use cases. Diversely routed redundant mirror connections between nodes ensure no single point of failure.
SANsymphony supports Asynchronous Remote Replication over conventional LANs and WANs using standard TCP/IP protocols. It automatically compresses transmissions to reduce bandwidth requirements. Secure, encrypted connections such as VPNs and trunked or aggregated multi-link circuits can be used to enhance the privacy and speed of inter-site transmissions. Disaster recovery sites may be initialized via network connections or by cloning virtual disks to transportable media at the primary site and shipping them to the remote destination. Replication is bi-directional. Topologies supported include 1-to-many, many-to-1 and many-to-many. (Note: An individual virtual disk may not be replicated to more than one remote node)
Multi-Pathing Support (Linux)
SANsymphony supports multi path drivers for different Linux versions and different OS types.
Multi-Pathing Support (Windows)
DataCore MPIO supports Auto failover and Auto Failback between primary and alternate paths. It also supports failover and failback between Fibre Channel and iSCSI inside a single host.
Multi-Pathing Support (VMware)
SANsymphony supports different versions of VMware ESXi using different path selection policies (ALUA), including round robin and most-recently-used.
Max # of SAN Ports Consumed
That number depends on the number of SANsymphony nodes within the SAN zone.
Fabric Zoning Considerations
SANsymphony requires two fabric zones, Storage Zone and Client Zone. If there are different switches used for storage and hosts, then there is no zoning required on any of the switches.
Zones Per Host
Since DataCore does not use LUN Masking techniques, all hosts could co-exist in a single zone. But as a best practice policy, DataCore recommends creating a zone for every type of Operating System (OS) to separate Windows servers from conflicting with Linux and other OS’s.
Explicit load balancing is achieved by spreading virtual disks across multiple ports. Multiple back-end channels to LUNs within a device are supported. If one back-end channel fails then all LUN I/O activity will continue on the remaining healthy back-end channels. Additional load balancing occurs across disks of the same tier in a pool. SANsymphony periodically looks for any devices that have unusually high activity (hot spots) compared to the other members of the pool. It then automatically fine tunes the pool by moving disk blocks to less active drives.
Non-stop data accessibility is configurable with paired redundant SANsymphony nodes that circumvent any single point of failure. Such innovative and cost-sensitive architecture ensures that service level obligations continue to be met in spite of component failures. Essentially, the I/O responsibilities associated with an outage, scheduled or unexpected, are distributed in real-time among the remaining storage resources being managed by SANsymphony. Hosts automatically exploit alternate paths to the other running SANsymphony node with the mirrored copy to maintain end-to-end high availability. When taking a SANsymphony node down for a prolonged period, control of that node’s shareable back-end storage resources can be transferred to a standby node without disrupting applications. The standby node takes the place of the one undergoing maintenance to maintain active mirrored copies of data for high availability. In addition, the standby node ensures that the overall throughput and responsiveness of the system remains intact.
Online Disk Expansion & Removal
Disks can be added to a SANsymphony node to expand the configuration on line without any down time. Also, when using thin provisioned disks, if more storage is needed, you can increase the pool size, without affecting any host or any Virtual disks presented to those hosts. Disks may also be removed non-disruptively from a pool. Simply select the drive to be taken out of service then, in the background, SANsymphony migrates the blocks across the remaining drives in the pool. Once complete, the physical drive may be removed.
LUN Security / Masking
SANsymphony does not use LUN Masking technology. All FC or iSCSI ports connected to a node are discovered automatically. Once an FC port WWN or iSCSI IQN are discovered, and a host is registered, a Virtual disk may employ that port. Only those hosts that have been granted explicit access to a virtual disk can detect that the disk exists. Other hosts will not see it.
Virtual / Physical Correlation (Troubleshooting)
Within SANsymphony, each Virtual disk may be created from multiple physical resources (storage). SANsymphony provides detailed information about which physical pool the Virtual disk is created from and which ports are used to present the Virtual disks to the hosts.
Sub-LUN migration: Dynamically promotes groups of most frequently accessed disk blocks (chunks) to fastest class of storage and demotes infrequently accessed chunks to lowest cost, slower tiers. Administrator can set tier preferences and override migration for special circumstances. Up to 15 tiers can be defined to distinguish between devices having different price/performance/capacity characteristics. Multiple devices are supported in each tier.
Takes the guess work out of how much disk space to allocate to an application. Configure up to 1 PB virtual disks and SANsymphony takes care of allocating actual disk space as the demand for physical space increases from
Post processing deduplication and compression may be selectively enabled for specific virtual disk pools. These processes reduce the space necessary to store data by eliminating duplicate blocks and compressing the single image, when possible.
SANsymphony assigns configurable amounts of the memory (RAM) inside each server that it has been installed on (DataCore node) into a high-speed storage cache. Advanced caching techniques inherent in SANsymphony’s design accelerate the response time of concurrent reads and writes from multiple application servers to virtual disks on the storage area network. The performance enhancements come inexpensively, exploiting the low-cost memory of the commercial processor platforms on which SANsymphony runs. SANsymphony’s cache is closely analogous to that found in modern high-end storage subsystems. However, it operates across multiple storage devices.
It resides between the operating system on the application server and the physical storage. Like caches found on storage subsystems it provides a variety of caching services noted below:
- Read-ahead: When a request for a block is satisfied, SANsymphony will automatically pre-fetch adjacent blocks into its cache on the principal that if “block X” is required, “blocks X+1 and X+2” will probably be requested shortly afterwards.
- Write-behind: Unless specifically told not to cache writes, SANsymphony will respond with “I/O complete” when a request is cached and mirrored to another node (multi-cast stable storage). It will flush (destage) the cached request to disk when convenient.
- Write-coalescing: One of the reasons that writes are not normally flushed immediately to the disk is to allow SANsymphony to better organize the sequence of writes and to concatenate writes from adjacent blocks into a single operation while the physical disks are busy.
SANsymphony’s caching acceleration applies to all manufacturers’ storage devices configured throughout a Storage Area Network. The caching strategies implemented by SANsymphony have been thoroughly tested and proven effective on generation after generation of hardware-based storage controllers and JBODs.
Increased performance for workloads characterized by many random writes, such as frequently updated databases, ERP and OLTP systems, are possible by selecting the sequential storage option (random write accelerator) for virtual disks. The technique uses additional capacity to expedite the data transfers.
QoS parameters can be set for individual hosts or groups of hosts as well as groups of virtual disks. For streaming applications which burst data, it’s best to regulate the data transfer rate (MB/sec) to minimize their impact. For transaction-oriented applications (OLTP), limiting the IOPS makes most sense. Both parameters may be used simultaneously.
SANsymphony commands may be issued programmatically rather than from the administrative console using an extensive library of PowerShell scripting commandlets. Essentially, any command available from the DataCore Console GUI may be scripted as well.
Alerts and Notifications
E-mail alerts and event logs provide clear notifications when the software detects unusual conditions including failure prediction notifications from S.M.A.R.T.–enabled storage. SNMP v1 queries and traps are also supported for interfacing to popular Systems Management and Systems Monitoring packages.
Set up relative priorities among Virtual disks by classifying their Storage Profile as Critical, High, Normal, Low, or Archive. SANsymphony functions like auto-tiering, remote replication and synchronous mirror recovery will give preferential treatment to higher priority volumes over less critical ones when resource contention exists. The storage profiles may be customized.
Topologies: Central SANs & Hyperconverged Storage (Server SAN)
SANsymphony may be configured on dedicated servers on the SAN to control external storage as a central SAN. The software may also be configured on physical and virtual machines to create converged systems from internal and direct-attached storage (DAS).
Private, Hybrid & Public Cloud
Extend the value of private, hybrid and public clouds through software-defined storage services provided by SANsymphony software. Access public cloud storage through Cloud Gateways and integrate directly with the OpenStack Cloud Operating System through Cinder block storage services.
Experience VVols functionality across existing and/ or all kinds of new storage. With VVols, vSphere administrators can ‘self-provision’ virtual volumes quickly from virtual storage pools without having to contact the storage administrator. They specify the capacity and class of service without having to know anything about the storage array that sits seamlessly beneath.