Samsung Enterprise SSD target Virtualization
September 2012, In a briefing for VMWorld, Samsung’s Enterprise SSD group gave us an update and overview on their virtualization solution using their SSD products. As the number of users and processes increases due to the number of VMs per CPU, the queue depth for concurrent I/O requests per storage volume increases rapidly. The standard 15K RPM rotating media HDDs, have a limitation of a functional queue depth of 2-3 due to latency and simultaneous access issues. Enterprise grade SSDs, due to their low latency and high IOPS allow them to address queue depths between 8 and 32 depending on RAID configuration. These enterprise devices are optimized for small data writes and multiple random read requests.
The Samsung SSDs feature all Samsung parts and is the only single vendor components drive on the market, this includes the flash cores, controller and firmware for optimized wear leveling and ECC. These drives are available directly, and through VAR service providers such as EMC. The EMC solution is still primarily based on SLC drives and technology, but are in the process of migration to their MLC and eMLC products which are more optimized for the virtual machine environment.
The configuration that is currently in vogue, is to use 128-256GB drive in a RAID configuration for boot drives and a read cache tier for server class machines in a DAS configuration. One of the keys in the selection of the RAID configuration and the size of the drive is based on the analysis of the workload for the servers and their tasks.
The Enterprise SSD solution also bring a GREEN aspect to the application. Based on the high throughput and IOPS of the drives, using their SATA interface (eMLC and SLC at 3.0Gbps and their 2.5″ MLS and mSATA drives at 6Gbps), the effective duty cycle for read and write is lower than with HDDs. As a result, there is a total run time of operation per day reduction and an overall net power reduction due to the lower power profile of Solid State vs rotating media. At this time there is no SAS configuration of these drives.
These resulting solutions are now being optimized by ODMs such as Pure Storage which is providing both VMWare server solutions and VDI infrastructure. These standard enterprise class DAS storage racks are power optimized and come with multi-drive and multi-rack management software configurations. The Enterprise products have been shipping in high volume for several years and are available to end users, data centers and OEMs/ODMs.
