Rethinking the guest?
I love working in the IT industry. Apart from being involved in an industry that is constantly changing and evolving, there are also lots of smart people out there who are doing & saying stuff that is interesting & challenging. I read a lot of blogs, and I read a lot of blogs of people who are working with competitors technology, or doing things that aren’t in my area of focus. I read an interesting post recently on the vinternals.com site called Rethinking the guest. I was going to comment on the post there, but thought I would blog my response instead.
Stu who posts there is a VMware guy and has a lot of interesting things to say. This post touches my area of work (Systems Management) and challenged me to think about how we do stuff, and how our world might evolve – thanks Stu!
Stu’s theory is that agent based management of guests needs to change, and posted four key areas where things could be done better. I find myself half agreeing and half disagreeing with him.
His first point is that managing patching with an agent is probably not efficient, and a sub point was that an enterprise software management system will likely do other stuff like hardware & software inventory, but we should disable hardware inventory because Vcenter captures that. I think that misses the important point that a lot of these systems that capture inventory then pass that information up to other systems (like your CMDB) and it’s nice to have a consistent place to capture that. I know that with System Center Configuration Manager I can grab all the information about my Windows inventory (software & hardware, physical or virtual) from a single place, and with partners like Quest I can grab information about my non-Windows environment as well from the same location. Do we need to complicate our environment by splitting our virtualised hardware inventory from our physical hardware inventory, or from our desktop inventory? And what if we want to do other things with our inventory system like baselining our desired configurations?
And agentless patch management is not without it’s problems. What about when the machine is turned off or unreachable (maybe the Windows Firewall is switched on)? What about when we want more control over when things happen – agentless patching can be good, but I think we give up control of a lot.
His second point is that agentless monitoring is also possible with the new Windows eventing subsystem. Again, that only gives us a subset of the information that we might care about. If all I care about is what events are being logged in the event log then sure, maybe that’s a potential solution. But what if I want deeper information? What if I want to be alerted when my disk space is low? What if I want deeper information about what an application is doing? If I really want to understand what my application is doing, merely looking at Windows events simply isn’t enough. I need to look at more metrics than events expose. That’s where System Center Operations Manager excels – and then using the PRO functionality inside Virtual Machine Manager we can use that contextual information to make smart decisions about remediating problems. Which might be live migrating/Vmotioning a machine to another node, or it might be provisioning a new VM to take the extra load because we’ve hit an OS limit that providing extra resource can’t solve.
And don’t get me started on SNMP. SNMP is an overcomplicated, insecure (at least until SNMP v3) mess that is great for monitoring simple network devices, but it really shows it’s age. And you simply don’t get the depth of information about Windows devices with SNMP.
His third point – backup. All I can say is, good to see VMware catching up on the great backup tools we have available with System Center Data Protection Manager which provides the same functionality but across physical and virtual environments. :)
I’ll skip VMsafe for now, I don’t know enough about it to comment – but I guess virtualisation will require security models to evolve, and VMsafe looks like one step in the process.
But his overall point – this will hinder the move to the cloud. This is where I start to agree. I think it probably will, and it’s one of the things people will have to consider when they look at their cloud strategy. So he’s right in that things have to change, but I’m not sure that the alternatives he’s proposed are good ones yet. It’s going to be interesting to see how the management tools industry does evolve to take into account the cloud. I’m just glad I’m here to see what happens!