The Hard Drive Shortage of 2012

As has been widely reported, the recent and unprecedented flooding in Thailand will cause a worldwide shortage in hard disk drives for at least the next 6 to 8 months. Most hard drive manufacturing facilities in the region are completely unusable and even if they were operational, much of the local supply chain has been wiped out. This prolonged shortage of hard disk drives could significantly impact deliveries of new servers, desktops and laptops.

As supplies dry up starting in the fourth quarter of 2011, we will begin to see the price of affected units increase. This of course is coming at a time when the consumption of storage is at an all-time high.

Most reports indicate that enterprise storage systems will not be affected by the shortage, at least from a supply perspective. These are the top tier of customers for the hard drive manufacturers and they will get first pick of any available hard drive inventory. It may however raise the price of enterprise storage because, while they will be able to get the units, enterprise vendors may have to pay more for them.

Most affected by this shortage will be PCs and laptops and users can expect lower availability along with higher prices. While this may cause some disruption in the business it’s certainly not a major ordeal for the enterprise if manufacturers delay their latest consumer computer rollouts. It may also spur more organizations to accelerate their virtual desktop deployments.

However, in between enterprise storage systems and user laptops are servers. While the bulk of server data is stored on a SAN or a NAS, hard disk drives in servers still play an important role in the enterprise infrastructure. They often, at a minimum, are used to boot the server before it can access shared storage and in many cases are the storage area for virtual memory swap space and log files. A shortage in server hard drives is a much bigger problem for the data center, where delaying rollouts of servers may not be an option.

Data centers need to make solving the shortage of hard drives for servers a priority decision. Fortunately there is a viable alternative in the form of flash-based storage. As covered in a recent Storage Switzerland article "DIMM SSDs Provide a Better, Faster Boot Drive" solid-state storage is an ideal server class technology and given the current shortage of hard disk drives, now may be an ideal time to switch.

By some estimates there are approximately 10 million hard disk-based boot drives being used in enterprise-class servers. About 50% of those use $80-$100 drives to provide business important boot and data storage to these systems. The remaining 50% use very inexpensive, approximately $40, HDDs and typically do not provide business important functions. For those servers in the first group that use the higher-quality, higher performing hard disk drives, it makes obvious sense to consider a flash storage alternative.

There are several options available to the storage manager when selecting the appropriate memory based storage device for their server environment. There are disk drive form factor SSDs, PCIe-based SSDs and the newer DIMM form-factor SSDs. The question is which of these makes the most sense for today's data center to select as the alternative choice for HDD technology?

One of the important factors when selecting a flash-based storage device for server class systems is the capacity and the performance of that device. Capacity is important because most servers, especially those that are getting the bulk of their data from a SAN or NAS, don’t need much storage. In other words, ‘less is more’ for the server-class solid state server drive. Actually, a device that’s about 64GB in size may be ideal. This provides enough capacity to store the base OS or hypervisor, as well as additional space to potentially store the application and the various memory swap files.

PCIe SSDs can quickly be eliminated from consideration for this type of use case. While they definitely provide very high performance most cannot perform a boot function and many have starting capacities in the 400 GB range making them overkill for a server that is going to access most of its data from a shared storage system anyway.

Hard drive form factor SSDs are a viable alternative. Because they are typically SATA or SAS based they can be booted from and can be found in relatively small capacities. They do of course, consume a hard drive slot which may prove valuable later when high-capacity hard drives are once again readily available in the market.

SSDs on a DIMM module can also be booted from and can be found in relatively low capacities, typically about 64 GB. Most importantly, they don’t consume a hard drive slot, instead are inserted into a memory DIMM slot that for many servers will never be used. For example, Viking provides a 64 GB MLC-based SATADIMM for less than $100. This configuration matches the price point that most data centers are paying for server class hard drives.

Performance requires more of a balance. Most servers would certainly benefit from a solid state system drive, since they will likely be used not only for boot but also for swap memory and log functions. But they don’t need the extreme high-end performance that PCIe SSD provides. This is an area where an SSD on a DIMM module can shine. It provides a high-performance 6 Gb per second interface at a relatively low cost.

Solving the hard drive shortage problem with a technology like SATADIMM opens up new opportunities for the data center. For example, thanks to high-speed virtual memory performance the servers may not need as much DRAM as they have in the past. Repeated tests have shown that the difference in virtual memory performance of a flash-based storage device compared to regular DRAM is almost unnoticeable. In short the DIMM form-factor SSD becomes more than just a tier of storage it also becomes a tier of DRAM.

Data centers can resolve the current drive disk shortage by using SSDs, for roughly the same price as hard disk drives. And they can do this while substantially improving the performance of not only the server boot process, but also virtual memory performance. As a result data centers could come out of the HDD shortage of 2012 with a better solution that has ample supply.