Introduction
EMC combines its Clariion and Celerra products to offer the EMC VNX Unified Storage. This is a robust platform for consolidation of legacy block storage, file servers, and direct-attached application storage, and enables organizations to cost-effectively manage multi-protocol file systems and multi-protocol block storage access.
Figure 1 below depicts the architecture of the EMC VNX Unified Storage.
Figure 1 : The architecture of the EMC VNX Series
The VNX series implements a modular architecture concurrently supporting native NAS, iSCSI, FC and FCoE protocols for host connectivity and 6Gb SAS backend topology. There are 12 CPU cores dedicated to high performance Block serving using six core CPUs on two SPs. There can be up to 48 CPU cores dedicated to networked File system management and data sharing via six core CPUs on eight X-Blades. Block connectivity is via FC, FCoE, and iSCSI, and File is via NAS including NFS, CIFS, MPFS, pNFS.
Like a CLARiiON each SP has an associated Management Module which provides the SP management connections via one Ethernet (RJ-45) port.
The VNX series includes SAS I/O module in slot 0 for connectivity to DAEs. Each port on this module represents a backend bus. The number of ports depends on system model. An 8 Gb FC I/O Module, located in slot 4, provide connectivity to the X-Blades (NAS head). They are factory installed in unified and file only systems. The rest of the I/O slots are used for block server access.
VNX DPE components include redundant SPs, two Power Supply/Cooling Modules, and the first set of drives for the VNX5500, VNX5300, and VNX5100 storage systems. The VNX DPE has the same management and service connections as the SPE based models. There are two RS-232 DB-9 serial ports, a Power LED and Fault LED, and two RJ-45 ports.
The VNX series comes with 2 DAE options: a 2U DAE may contain up to 25 2.5 inch, 6Gbit SAS drives and a 3U DAE may contain up to 15 3.5 inch, 6Gb SAS drives. Both types of DAEs may be installed in the same array. Each DAE can contain a mixture of all drive types (Flash, SAS, and NL SAS). The DAEs are connected via a 4 lane, 6Gb/s per lane connection which results in a 24Gb/s SAS connection.
The DAE includes 15 disk drives, two Link Control Cards (LCC A and LCC B), and two Power Supply/Cooling Modules (PS A and PS B). The LCCs and Power Supplies are locked into place using captive screws to ensure proper connection to the midplane.
The VNX series Data Mover Enclosure can contain one or two X-Blades. The X-Blades provide File connectivity via DART Operating System. X-Blades include a four port 8 Gb Fibre Channel I/O Module in slot 0. Two ports are for connectivity to the Storage Processors and two are for connectivity to a backup tape device. The rest of the I/O slots are used for File connectivity and there must be at least one network I/O Module in each X-Blade. The VNX series storage systems also support X-Blade failover.
Owing to this ‘fail-proof’ architecture, the EMC VNX series is widely used in large physical and virtualized server farms to provide reliable storage services. As data integrity and accessibility is key in such environments, even the smallest of slips in the performance of this storage platform - be it a gradual erosion of storage space in a file system, a slight increase in the I/O activity on a disk, or a negligible dip in cache hits - will not be tolerated. To ensure the 24x7 availability and peak performance of the EMC VNX series, administrators need to closely monitor the operations and overall
