I love it when a new word is coined in the blogosphere. This one comes from Tony Pearson over at IBM: “blegging.” A “bleg” is, I guess, a blog post that is asking for something from the reader, as I did with my recent de-duplication questionnaire for vendors. Tony, I am going to bleg for something again. (Thanks, by the way, for your response to the de-dupe questionnaire.)
This time the bleg is for your assistance in clarifying a few issues about virtualization using LPARs on an IBM z10.
I am, as you know, favorably predisposed to use LPAR technology, rather than x86 with extents and hypervisor software, to consolidate and virtualize servers and I have written about the value proposition both here and in mainstream pubs. The problem is that some of what I learned from chats and formal interviews and press releases out of Big Blue, and reported in the trades, has caused a ruckus from readers.
Press materials around z10, for example, stated that one could use LPARs and virtualize up to 1500 x86 servers at a fraction of the cost that it would take to do so with VMware. The exact number quoted was “$660 per VM.” Compared to doing the same with VMware, that sounded like a great bargain. A reader now challenges this number, stating that z/OS only supports 60 LPARs. So, where is the 1500 number coming from? Good question. So, I am blegging for an answer.
Second, IBM jocks told me that Sysplex provides a much more robust guarantee against a VM meltdown by enabling load to shift to other processor modules if one fails. This is, of course, much more resilient sounding than a VMware hosting metaphor. Except, the reference to Sysplex, a reader suggests, must have been metaphorical, since z/OS and z10 don’t feature Sysplex technology. I bleg for some clarification on this point. (The fellow also said that while z10 supports multiple processor modules, he didn’t think that the cost for this technology was part of the dollars analysis that went into the “1500 servers for $660 per” statements made by IBM. Does this sound accurate?)
Finally, I had noted that with tools such as DFSMS and DFHSM resource utilization efficiency was better behind a mainframe than behind open servers. The reader gently reminded me that DFSMS and DFHSM had not been fully ported to zOS. Where does this stand? Are their other facilities in the works for zOS that are comparable to SMS and HSM? I bleg to know.
I have directed these questions to IBM through analyst relations channels, but have received no response. Since you seem to be the most responsive IBMer I know, can you clarify this for me, Tony? As I said, IBM’s VMware alternative sounded great to me, and I want to believe. But, this confusion is making that difficult.