SRDF
Encyclopedia
SRDF is a family of EMC
products that facilitates the data replication from one Symmetrix storage array to another through a Storage Area Network
or IP
network.
SRDF logically pairs a device or a group of devices from each array and replicates data from one to the other synchronously or asynchronously. An established pair of devices can be split, so that separate hosts can access the same data independently (maybe for backup), and then resynchronised.
In synchronous mode (SRDF/S), the primary array waits until the secondary array has acknowledged each write before the next write is accepted, ensuring that the replicated copy of the data is always as current as the primary. However, the latency due to propagation increases significantly with distance.
Asynchronous SRDF (SRDF/A) transfers changes to the secondary array in units called delta sets, which are transferred at defined intervals. Although the remote copy of the data will never be as current as the primary copy, this method can replicate data over considerable distances and with reduced bandwidth requirements and minimal impact on host performance.
Other forms of SRDF exist to integrate with clustered environments and to manage multiple SRDF pairs where replication of multiple devices must be consistent (such as with the data files and log files of a database application).
EMC Corporation
EMC Corporation , a Financial Times Global 500, Fortune 500 and S&P 500 company, develops, delivers and supports information infrastructure and virtual infrastructure hardware, software, and services. EMC is headquartered in Hopkinton, Massachusetts, USA.Former Intel executive Richard Egan and his...
products that facilitates the data replication from one Symmetrix storage array to another through a Storage Area Network
Storage area network
A storage area network is a dedicated network that provides access to consolidated, block level data storage. SANs are primarily used to make storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers so that the devices appear like locally attached devices...
or IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
network.
SRDF logically pairs a device or a group of devices from each array and replicates data from one to the other synchronously or asynchronously. An established pair of devices can be split, so that separate hosts can access the same data independently (maybe for backup), and then resynchronised.
In synchronous mode (SRDF/S), the primary array waits until the secondary array has acknowledged each write before the next write is accepted, ensuring that the replicated copy of the data is always as current as the primary. However, the latency due to propagation increases significantly with distance.
Asynchronous SRDF (SRDF/A) transfers changes to the secondary array in units called delta sets, which are transferred at defined intervals. Although the remote copy of the data will never be as current as the primary copy, this method can replicate data over considerable distances and with reduced bandwidth requirements and minimal impact on host performance.
Other forms of SRDF exist to integrate with clustered environments and to manage multiple SRDF pairs where replication of multiple devices must be consistent (such as with the data files and log files of a database application).
See also
- Symmetrix storage arraySymmetrixThe Symmetrix system is EMC Corporation's flagship enterprise storage array. The Symmetrix development has been led by Moshe Yanai, who joined EMC in 1987, until shortly before his leaving EMC in 2001. There have been many generations of Symmetrix hardware, with the first appearing in 1990 and the...
- EMC CorporationEMC CorporationEMC Corporation , a Financial Times Global 500, Fortune 500 and S&P 500 company, develops, delivers and supports information infrastructure and virtual infrastructure hardware, software, and services. EMC is headquartered in Hopkinton, Massachusetts, USA.Former Intel executive Richard Egan and his...
- Storage replication
- Storage Area NetworkStorage area networkA storage area network is a dedicated network that provides access to consolidated, block level data storage. SANs are primarily used to make storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers so that the devices appear like locally attached devices...
- Super-resolution Direction Finding