Technical overview
The technical overview topics provide information about the major concepts you need to understand to use the system.
- SAN Volume Controller overview
The SAN Volume Controller system combines software and hardware into a comprehensive, modular appliance that provides symmetric virtualization. - Application servers
An application server is a host that is attached to the system and runs applications. - Array configurations
An array is an ordered configuration, or group, of physical devices (disk drive or flash drive modules) that is used to define logical volumes or devices. An array is a type of MDisk that is made up of disk drives; these drives are members of the array. A Redundant Array of Independent Disks (RAID) is a method of configuring member drives to create high availability and high performance systems. (This topic applies to flash drives that provide high-speed managed-disk (MDisk) capability for the system.) - Batteries
SAN Volume Controller 2145-DH8 and SAN Volume Controller 2145-SV1 nodes contain two batteries that provide backup power to the system when an unforeseen loss of AC power occurs. The battery within a node supplies power only to that node during an unscheduled power loss. - Capacity indicators
The system uses base-2 (binary numeral) as capacity indicators for volumes, drives, and other system objects. The management GUI and the command-line interface (CLI) use different abbreviations to indicate capacity. - Copy offload
Offloaded data transfer (ODX) is a feature in Microsoft Windows Server 2012. ODX function frees up hosts and speeds the copy process by offloading the entire orchestration to a storage array. - Copy Services functions
The system provides Copy Services functions that can be used to improve availability and support disaster recovery. - Data migration
The system allows you to migrate data across MDisks without interfering with any host applications that are simultaneously accessing or writing data. - Drives
For SAN Volume Controller 2145-SV1 and SAN Volume Controller 2145-DH8 , the system supports flash drives, enterprise, and nearline class drives. A drive object represents the physical drive. The system creates this object automatically when a supported drive is detected and a drive ID is assigned.The system supports a range of enterprise-class, nearline-class or flash drives. A drive object represents the physical drive. The system creates this object automatically when a supported drive is detected and a drive ID is assigned. - Easy Tier function
The system includes IBM® Easy Tier®, which is a function that responds to the presence of drives in a storage pool that also contains hard disk drives (HDDs). The system automatically and nondisruptively moves frequently accessed data from HDD MDisks to flash drive MDisks, thus placing such data in a faster tier of storage. - Enclosures
Enclosures are rack-mounted hardware that contains several components of the system. Enclosures can be used to extend the capacity of the system. They are only supported on SAN Volume Controller 2145-DH8 or SAN Volume Controller 2145-SV1 nodes. For other models of the system, you must use external storage systems to provide capacity for data. The term enclosure is also used to describe the hardware and other parts that are plugged into the enclosure. - Encryption
A SAN Volume Controller 2145-DH8 or SAN Volume Controller 2145-SV1 system supports optional encryption of data at rest. This support protects against the potential exposure of sensitive user data and user metadata that is stored on discarded, lost, or stolen storage devices. To use encryption on the system, an encryption license is required for each pair of nodes that support encryption. - External storage systems
An external storage system, or storage controller, is a device that coordinates and controls the operation of one or more disk drives. A storage system synchronizes the operation of the drives with the operation of the system as a whole. - Fibre Channel port numbers and worldwide port names
Fibre Channel (FC) ports are identified by their physical port number and by a worldwide port name (WWPN). - Heartbeat email
The system sends an inventory email once every 24 hours to support users who are identified in the email user list for the call home function. This heartbeat email automatically begins when at least one valid email server exists, one or more support email users are defined, and the startemail command is issued. The system does not send heartbeat email to other email users. - Host clusters
A host cluster is a group of logical host objects that can be managed together. For example, you can create a volume mapping that is shared by every host in the host cluster. The system uses internal protocols to manage access to the volumes and ensure consistency of the data. Host objects that represent hosts can be grouped in a host cluster and share access to volumes. New volumes can also be mapped to a host cluster, which simultaneously maps that volume to all hosts that are defined in the host cluster. - Host mapping
Mapping is the process of controlling which hosts or host clusters have access to specific volumes within the system. - Host objects
A host object is a logical object that represents a list of worldwide port names (WWPNs) and a list of iSCSI names that identify the interfaces that the host system uses to communicate with the system. Fibre Channel connections use WWPNs to identify host interfaces to the system. iSCSI names can be either iSCSI qualified names (IQNs) or extended unique identifiers (EUIs). - I/O governing rate
The I/O governing rate sets the maximum amount of I/O activity that a host sends to a volume. The governing rate can be expressed in I/Os per second or MB per second. - I/O group
A pair of nodes is known as an input/output (I/O) group. An I/O group is defined during the system configuration process. - Internal storage
Internal storage is directly attached to the system. The system can manage a combination of internal and external storage and represents all the detected storage as MDisks. - Inventory information email
An inventory information email summarizes the hardware components and configuration of a system. Service personnel can use this information to contact you when relevant software updates are available or when an issue that can affect your configuration is discovered. It is a good practice to enable inventory reporting. - Management GUI
The system includes an easy-to-use management GUI to help you to monitor, manage, and configure your system. - MDisks
A managed disk (MDisk) is a logical unit of physical storage. MDisks are either arrays (RAID) from internal storage or volumes from external storage systems. MDisks are not visible to host systems. - Nodes
Each node is a single processing unit within a system. - Object naming
All objects in a system have names that are user-defined or system-generated. - Object overview
Before you set up your system, you must understand the concepts and the objects in the environment. - Performance statistics
Real-time performance statistics provide short-term status information for the system. The statistics are shown as graphs in the management GUI. - SAN fabric overview
The SAN fabric is an area of the network that contains routers and switches. A SAN is configured into a number of zones. A device that uses the SAN can communicate only with devices that are included in the same zones that it is in. A system requires several distinct types of zones: a system zone, host zones, and disk zones. The intersystem zone is optional. - SANs
A storage area network (SAN) is a pool of storage systems that are interconnected to the servers in an enterprise. A SAN administrator is the person responsible for administering the various resources that make up the SAN. - Setting up an SSH client
Secure Shell (SSH) is a client/server network application. It is used as a communication vehicle between the host system and the system command-line interface (CLI). - Service and support
The system provides several options to help you to identify and resolve problems that may require assistance from service support personnel. - Standard and persistent reservations
The SCSI Reserve command and the SCSI Persistent Reserve command are specified by the SCSI standards. Servers can use these commands to prevent ports in other servers from accessing particular LUNs. - Storage Management Initiative Specification
The Storage Management Initiative Specification (SMI-S) is a design specification of the Storage Management Initiative (SMI) that is launched by the Storage Networking Industry Association (SNIA). - Storage pools
In general, a pool or storage pool is an allocated amount of capacity that jointly contains all of the data for a specified set of volumes. The system supports standard pools (parent pools and child pools) and data reduction pools. - Supported operating platforms
Use one of the supported operating hardware platforms to host the system software. - Switches
The system connects to host systems and storage devices on the storage area network (SAN) through switches. Switches from different vendors can be used together in the system configuration. - Systems
Systems are collections of nodes. Systems can consist of between two to eight nodes. - System layers
The system layer affects how the system interacts with a SAN Volume Controller system and other external Storwize® family systems. - Technician port
The technician port is an Ethernet port on the back panel of 2145-SV1 and 2145-DH8 nodes that you use to configure the node. - Throttles
Throttles are a mechanism to control the amount of resources that are used when the system is processing I/Os on supported objects. The system supports throttles on hosts, host clusters, volumes, copy offload operations, and storage pools. If a throttle limit is defined, the system either processes the I/O for that object, or delays the processing of the I/O to free resources for more critical I/O operations. - Transparent cloud tiering
Transparent cloud tiering is a licensed function that enables volume data to be copied and transferred to cloud storage. The system supports creating connections to cloud service providers to store copies of volume data in private or public cloud storage. - User roles
Each user of the management GUI must provide a user name and a password to sign on. Each user also has an associated role such as monitor, copy operator, service, administrator, or security administrator. These roles are defined at the clustered system level. For example, a user can be the administrator for one system, but the security administrator for another system. - Virtualization
Virtualization is a concept that applies to many areas of the information technology industry. - Vital product data
Vital product data (VPD) is information that uniquely records each hardware and licensed-internal-code element in the nodes. - Volumes
A volume is a logical disk that the system presents to attached hosts.
Parent topic: Product overview