Storage Nation

I recently spoke to two storage analysts about the effect of server virtualization on storage resources. Both agreed that the effect of virtual machines will be to increase the I/O workload coming from the VM hardware platform by the number of VMs that are virtualized and that the resulting I/O would be very random.   They agreed that the increasing workload required a storage system that could scale up as well as scale out as I noted in my previous post on  Scale up or Scale out.  Their next question was about the need for cache when I/O loads are random, since random I/Os are unpredictable and do not benefit from cache prefetch or cache reuse.

If you saw the comments by EMC’s Barry Burke to my last blog post, Barry give his explanation of how VMAX works.

I visited a customer last week who was trying to run four 6 node ESX clusters with 200 to 240 instances per cluster on a large modular storage system.  It was not surprising that the modular storage system could not support that workload.