Solid-State Disk….What is it and who needs it?

Solid-State Disk, (SSD) is seen by the Operating Systems as a standard SCSI disk drive. However, unlike disk based arrays, Solid State Disk is made of DDR Ram. This allows for throughput of over 250,000 IOPS vs. fewer than 10,000 IOPS in the fastest of disk based arrays.

Think back over the past decade and look where we are today comparatively in regards to speed on a network:

• We were at 10BaseT networks, now we’ve got 10Gb Networks – A 100X increase


• We had 133MHz processors, we’re now approaching 4GHz – A 35X increase


• Per Gilder’s law- Aggregate bandwidth grows at 3x the speed of processor speed.


• Hard Disk Speed over this same time period has increased less than 5% A YEAR

The mechanical natures of today’s storage arrays cause this delay and therefore cause latency and I/O bottlenecks. Unfortunately, as the networks and servers become even faster, and the densities of the disk drives become greater, the performance gap will only widen and create even larger degrees of latency and I/O problems.

Because Solid-State Disks add no moving parts in the datapath, the speed is cut from an average 3-6ms. access time to roughly 15/1000’s of a millisecond. This creates dramatic improvements in I/O and reduced latency--translating to faster network performance & greater user satisfaction.

Why Not Add More Servers or Spindles?

Add Processors			Add Disk Spindles
	Increases Rack Space			Increase Rack Space
	Increases Mgmt. Costs			Increases Mgmt. Costs
	Increases Warr/Svc Costs			Increases Warr/Svc Costs
	Increases Recurring Softw. Costs

Why Not Just Cache Servers?

Increasing server cache is a great idea. The problem is that cache on a server only helps that server. What
if you could take the same or even a greater capacity of cache than the server is capable of upgrading to and serve it up on the network as cache that any and all servers can use, regardless of O/S, platform or mixtures of each? Because SSD presents itself as a disk, now you have the opportunity to put large segments of cache which can be used by all servers given permissions to do so.

In addition, the average lifecycle of performance servers is less than 36 months. Any investment of cache made to those servers may be lost upon installation of the new CPU’s. With a RamSan, simply unplug the fibre-channel connections from the old server and plug into the new and you’re up and running.

Many organizations will have servers which are only used heavily at certain times of the month. A perfect example is batch processing. With SSD, the administrator simply drags and drops a certain capacity of cache to a LUN created for the batch processing server(s) and batch processing can be done in record time.

What Applications Can Solid-State Disk Improve?

SSD is great for speeding any application where I/O is a problem. Typical applications include Databases, MetaData, Web Hosting/Traffic, Biometrics, Email, Video Editing, etc. Basically, if you have an I/O bottleneck, the Ramsan can GREATLY improve your environment.

In a typical database scenario, as little as 2% of files can be directly linked to 65-80% of overall activity on the network. These files are typically indexes, tables, temps and logs…small in overall capacity, but heavy on accesses. These would be perfect candidates to move to SSD.

Remember, SSD is not meant to replace your RAID or Tape, but to enhance it.

How Can SSD help in Server Consolidation?

By putting the most accessed files on SSD, this takes the majority of the hits off the disk sets. In doing so, the disks then run faster, most importantly, the servers no longer have to wait for the disks, and therefore provide faster overall network performance. In most organizations, the average CPU Utilization, is roughly 50%. This means that servers work ½ the time and wait ½ the time. By implementing SSD, lighting fast response times results in typical utilizations of over 90%.

The Result: The typical datacenter can do much more with fewer servers to manage and support.

The savings in the reduction of software licenses, maintenance, and database tuning costs make the ROI on solid-state disk extremely attractive.