Last week, fellow IBMer Ron Riffe started his three-part series on the Storage Hypervisor. I discussed Part I already in my previous post [Storage Hypervisor Integration with VMware]. We wrapped up the week with a Live Chat with over 30 IT managers, industry analysts, independent bloggers, and IBM storage experts.
This week, Ron continues this meme with his post [Enabling Private IT for Storage Cloud -- Part II (management controls)]. Here's an excerpt:
A storage hypervisor increases the utilization of storage resources, and optimizes what is most scarce in your environment. For Linux, UNIX and Windows servers, you typically see utilization rates of 20 to 35 percent, and this can be raised to 55 to 80 percent with a storage hypervisor. But what is most scarce in your environment? Time! In a competitive world, it is not big animals eating smaller ones as much as fast ones eating the slow.
If this sounds all too familiar, it is similar to the benefits that one gets from a server hypervisor -- better utilization of CPU resources, optimizing the management and administration time, with the agility and flexibility to deploy new technologies in and decommission older ones out.
Arthur Cole disagrees. His blog post asks [
'Storage Virtualization' or 'Vir
Jon Toigo on his DrunkenData blog brings back the sanity with his post [Once More Into the Fray]. Here is an excerpt:
Did you miss out on last Friday's Live Chat? We are doing it again this Friday, covering parts I and II of Ron's posts, so please join the conversation! The virtual dialogue on this topic will continue in another [Live Chat] on September 30, 2011 from 12 noon to 1pm Eastern Time.
Continuing my coverage of last week's Data Center Conference 2009, my last breakout session of the week was an analyst presentation on Solid State Drive (SSD) technology. There are two different classes of SSD, consumer grade multi-level cell (MLC) running currently at $2 US dollars per GB, and Enterprise grade single-level cell (SLC) running at $4.50 US dollars per GB. Roughly 80 to 90 percent of the SSD is used in consumer use cases, such as digital cameras, cell phones, mobile devices, USB sticks, camcorders, media players, gaming devices and automotive.
While the two classes are different, the large R&D budgets spent on consumer grade MLC carry forward to help out enterprise grade SLC as well. SLC means there is a single level for each cell, so each cell can only hold a single bit of data, a one or a zero. MLC means the cell can hold multiple levels of charge, each representing a different value. Typically MLC can hold 3 to 4 bits of data per cell.
Back in 1997, SLC Enterprise Grade SSD cost roughly $7870 per GB. By 2013, Consumer Grade 4-bit MLC is expected to be only 24 cents per GB. Engineers are working on trade-offs between endurance cycles and retention periods. FLASH management software is the key differentiator, such as clever wear-leveling algorithms.
SSD is 10-15 times more expensive than spinning hard disk drives (HDD), and this price difference is expected to continue for a while. This is because of production volumes. In 4Q09, manufacturers will manufacturer 50 Exabytes of HDD, but only 2 Exabytes of SSD. The analyst thinks that SSD will only be roughly 2 percent of the total SAN storage deployed over the next few years.
How well did the audience know about SSD technology?
SSD does not change the design objectives of disk systems. We want disk systems that are more scalable and have higher performance. We want to fully utilize our investment. We want intelligent self-management similar to caching algorithms. We want an extensible architecture.
What will happen to fast Fibre Channel drives? Take out your Mayan calendar. Already 84mm 10K RPM drives are end of life (EOL) in 2009. The analyst expects 67mm and 70mm 10K drives will EOL in 2010, and that 15K will EOL by 2012. A lot of this is because HDD performance has not kept up with CPU advancements, resulting in an I/O bottleneck. SSD is roughly 10x slower than DRAM, and some architectures use SSD as a cache extension. The IBM N series PAM II card and Sun 7000 series being two examples.
Let's take a look at a disk system with 120 drives, comparing 73GB HDD's versus 32GB SSD's.
There are various use cases for SSD. These include internal DAS, stand-alone Tier 0 storage, replace or complement HDD in disk arrays, and as an extension of read cache or write cache. The analyst believes there will be mixed MLC/SLC devices that will allow for mixed workloads. His recommendations: