Wednesday, June 6, 2012

VMAX architecture


The Symmetrix V-Max family includes 2 options for scalability and growth. The V-Max series scales from 48 to 2,400 disks and provides 2 Peta bytes of usable protected capacity when configuring all 1TB SATA disks. The V-Max SE scales from 48 to 360 disks and is intended for smaller capacity needs that require Symmetrix performance, availability, and functionality.

The V-Max architecture is comprised of up to 8 engines. Each engine is a pair of directors. Each director is a 2-way quad-core Intel Xeon 5400 system with up to 64GB memory.It provides support for Fibre Channel, iSCSI, Gigabit Ethernet, and FICON connected hosts. Front-end and back-end connectivity has doubled over the DMX-4 with up to 128host ports and 128 disk channels. The V-Max also leverages 2.3 Gigahertz multi-core processors. The new Virtual Matrix provides the interconnect that enables resources to be shared across all V-Max engines to enable massive scale out


The Virtual Matrix Architecture replaces individual, function-specific directors with Symmetrix V-Max Engines, each containing a portion of Global Memory and two directors capable of managing front end, back end, and remote connections simultaneously.. Scalability has improved in all aspects: front-end connectivity, Global Memory, back-end connectivity, and usable capacity. The increased usable disk capacity is the result of an increase in Global Memory combined with a significant reduction in metadata overhead allowing 2400 devices to be configured with RAID types other than RAID 1 resulting in a dramatic increase in usable capacity. The Virtual Matrix is redundant and dual active and supports all Global Memory references, all messaging, and all management operations including internal discovery and initialization, path management, load balancing, fail over, and fault isolation within the array. The Symmetrix V-Max array is comprised of 1 to 8 V-Max Engines. Each V-Max Engine contains two integrated directors .Each director has two connections to the V-Max Matrix Interface Board Enclosure (MIBE) via the System Interface Board or SIB ports. Since every director has two separate physical paths to every other director via the Virtual Matrix, this is a highly available interconnect with no single point of failure



Each director also has 8 back-end 4Gb/s FC ports (comprised of quad-port HBAs) and various options for the front-end including 8 4Gb/s FC ports. In the full configuration of 128 4Gb/s FC ports on the front and back ends, the expectation is that this system could deliver 40GB/s if there a no bottlenecks in the system architecture.

V-Max Engine Architecture







The full VMax system comprises 11 racks!



The center rack is for the VMax engines, the other 10 are storage bays. Each storage bay can hold up to 240 drives. There are 160 disk array enclosures, 64 directly connected, and 96 daisy chained. There are 8 VMax engines, as denoted by each color. 

When configuring the Symmetrix, there are different types of Hyper devices that can be configured.For example:

Standard devices (STD) are configured for normal production operations
Business Continuance (BCV) devices are configured for TimeFinder/Mirror replication
Virtual Devices (VDEV) are configured for TimeFinder/SNAP local pointer-based replication
Dynamic Reallocation Volumes (DRV) devices are configured for Symmetrix Optimizer hyper re-location
TDEV devices are virtual cache-only devices that can grow in capacity
Save Devices are configured for Time Finder/SNAP and/or TDEV devices
R1 and R2 for remote replication

Virtual devices can reduce wasted disk space because the actual data is kept in a common pool ;only what is used is allocated in the common pool and the pool is shared by many TDEV devices. Eg: the host has a 100 GB Virtual TDEV device, the TDEV device uses no disk space, the Save pool contains the actual data, and only 20 GB is allocated until more space is required. The allocated capability is managed by EMC software