Top 10 blog posts for 2011

Merry Christmas! Buon Natale! Frohe Weihnachten! by Jakob Montrasio (cc) (from Flickr)
Merry Christmas! Buon Natale! Frohe Weihnachten! by Jakob Montrasio (cc) (from Flickr)

Happy Holidays.

I ranked my blog posts using a ratio of hits to post age and have identified with the top 10 most popular posts for 2011 (so far):

  1. Vsphere 5 storage enhancements – We discuss some of the more interesting storage oriented Vsphere 5 announcements that included a new DAS storage appliance, host based (software) replication service, storage DRS and other capabilities.
  2. Intel’s 320 SSD 8MB problem – We discuss a recent bug (since fixed) which left the Intel 320 SSD drive with only 8MB of storage, we presumed the bug was in the load leveling logic/block mapping logic of the drive controller.
  3. Analog neural simulation or digital neuromorphic computing vs AI – We talk about recent advances to providing both analog (MIT) and digital versions (IBM) of neural computation vs. the more traditional AI approaches to intelligent computing.
  4. Potential data loss using SSD RAID groups – We note the possibility for catastrophic data loss when using equally used SSDs in RAID groups.
  5. How has IBM researched changed – We examine some of the changes at IBM research that have occurred over the past 50 years or so which have led to much more productive research results.
  6. HDS buys BlueArc – We consider the implications of the recent acquisition of BlueArc storage systems by their major OEM partner, Hitachi Data Systems.
  7. OCZ’s latest Z-Drive R4 series PCIe SSD – Not sure why this got so much traffic but its OCZ’s latest PCIe SSD device with 500K IOPS performance.
  8. Will Hybrid drives conquer enterprise storage – We discuss the unlikely possibility that Hybrid drives (NAND/Flash cache and disk drive in the same device) will be used as backend storage for enterprise storage systems.
  9. SNIA CDMI plugfest for cloud storage and cloud data services – We were invited to sit in on a recent SNIA Cloud Data Management Initiative (CDMI) plugfest and talk to some of the participants about where CDMI is heading and what it means for cloud storage and data services.
  10. Is FC dead?! – What with the introduction of 40GbE FCoE just around the corner, 10GbE cards coming down in price and Brocade’s poor YoY quarterly storage revenue results, we discuss the potential implications on FC infrastructure and its future in the data center.


I would have to say #3, 5, and 9 were the most fun for me to do. Not sure why, but #10 probably generated the most twitter traffic. Why the others were so popular is hard for me to understand.


vSphere 5 storage enhancements

Doyle on a Riemann Sphere by fdecomite (cc) (from Flickr)
Doyle on a Riemann Sphere by fdecomite (cc) (from Flickr)

Twitter was all abuzz yesterday about the recent VMware vSphere 5 announcement. Although there were quite a few changes that came out, the ones of most interest to me were all in the data storage arena:

  • DAS storage appliance – VMware vSphere 5 now has a virtual machine that can take server DAS and offer a shared storage service to other VMs.  The storage appliance is only available for the Essentials+ and below licensing options and is restricted to a three physical ESX server environment.
  • Host based replication service – vSphere 5 now offers a software only replication option to support disaster recovery.  The host-based replication service is not considered high-bandwidth and will not compete with storage or other hardware replication products but can be used to support heterogeneous storage replication.
  • Storage DRS – For vSphere 5 Enterprise edition and above once storage pools have been defined, Storage DRS can migrate VMs to other storage within a pool to automatically load balance IO activity.
  • Storage performance guarantees – For Enterprise edition and above vSphere 5 can provide a QOS capability for IO activity allowing designated, high priority VMs to gain preferential access to IO queues and such so that they perform better in a noisy, mixed environment.
  • IO performance improvements – VMware claims a 4X improvement in storage throughput with vSphere 5.
  • Linked clones – VMware now offers a storage option that can chain two read-writeable copies of a VMDK together and only store the changes needed for the second copy enabling quicker and more efficient storage provisioning for similar VMs.

DAS appliances have been around for awhile now but have never been really popular. However for smaller shops, this might be just the thing to help them start down the virtualization path.  Similarly the VMware host- based data replication is a low-end capability that might help these customers virtualize, although this may be a bit more sophisticated than most SMB data centers need.

Storage performance guarantees, DRS, and automatic provisioning seem to be targeted at the higher end shops with vast storage farms to manage.  Such shops would like to automate (as much as possible) some of the performance management, provisioning and service management that they currently need to do manually to ease VMware’s storage admins workloads.

Linked clones and IO performance improvements will benefit all shops. However, IO improvements should enable bigger more mission critical applications to be virtualized.  On the other hand, linked clones will help all customers quickly and more efficiently deploy lot’s of similar VMs.


The big complaint on Twitter yesterday was on VMware’s licensing change. Apparently vSphere is licensed on a vRAM basis (the amount of virtual memory assigned to all VMs in a shop).  How this will impact customer costs is subject to debate but each vSphere processor license gets a certain amount of vRAM available to it (from 24GB to 48GB of vRAM per slot, depending on license level).

There’s been lot’s of talk about VASA and VAAI capabilities that are being rolled out by storage vendors but that will need to wait until another post.