EMC VNX Components and their purpose

Components and their purpose

Standby Power Supply – SPS – This is a 1u uninterruptible power supply designed to hold the Storage processors during a power failure for long enough to write any data in volatile memory to disk.

Disk Processor Enclosure – DPE (VNX5100/5300/5500/5200/5400/5600/5800/7600 models) – This is the enclosure that contains the storage processors as well as the Vault Drives and a few other drives. It contains all connections related to block level storage protocols including Fiber Channel and iSCSI.

Storage Processor Enclosure – SPE (VNX5700/7500/8000 models) – This is the enclose that contains the storage processors on the larger VNX models. It is in place of the DPE mentioned above.

Storage Processor – SP –  Usually followed by “A” or “B” to denote if which one it is, all VNX systems have 2 storage processors. It is the job of the storage processor to retrieve data from the disk when asked, and to write data to disk when asked. It also handles all RAID operations as well as Read and Write caching. iSCSI and additional Fiber Channel ports are added to the SP’s using UltraFlex modules.

UltraFlex I/O Modules – These are basically PCIe Cards that have been modified for use in a VNX system. They are fitted into a metal enclosure that is then inserted into the back of the Storage Processors or Data Movers, depending on if it is for Block or File use.

Control Station – CS –  Normally preceded by “Primary” or “Secondary” as there are at least 1, but most often 2 control stations per VNX system. It is the job of the control station to handle management of the File or Unified components in a VNX system. Block only VNX arrays do not utilize a control station. However in a Unified or File only system the Control stations run Unisphere and pass any and all management traffic to the rest of the array components.

 Data Mover Enclosure – Blade Enclosure – This enclosure houses the data movers for file and unified VNX arrays.

Data Movers – X-Blades – DM – Data movers  (aka X-Blades) connect to the storage processors over dedicated fiber channel cables and provide File (NFS, pNFS, and CIFS) access to clients. Think of a data mover like a linux system which has SCSI drives in it, it then takes those drives and formats them with a file system and presents them out one or more protocols for client machines to access.

Disk Array Enclosure – DAE – DAE’s come in several different flavors, 2 of which are depicted in the quick reference sheet. One is a 3u – 15 disk enclosure which holds 15 – 3.5″ disk drives; the second is a 2u – 25 disk enclosure which holds 25 – 2.5″ disk drives; and finally the third is a 4u – 60 disk enclosure which holds 60 – 3.5″ drives in a pull out cabinet style enclosure. The third type is the more rare and are not normally used unless rack space is at a premium.