Yea, some would say this post is probably overdue but lately I have sincerely been thinking. Have we been drinking some Kool-Aid around this feature? I couldn’t help but have some concerns around possible implementation of this feature in VCD installments. I in particular, am not sold on it completely. Here are just some quick reasons for me that didn’t exactly sell me.
- It’s a very “new” feature in regards to VCD which is still early in its years as a cloud platform.
- No way of currently updating those linked clones unlike VMware View. (some admin over head as well as using local and shared catalogs)
- Added complexity (with linked images, snap chains, and how you have handle storage motion)
- By Default ALL linked clone images are mis-aligned. (VMware has yet to address this problem) In some cases this could be a compounding factor causing some additional I/O overhead.
- Design has to be highly considered and evaluated with a max of 8 node clusters (This will affect current installments as well)
So yeah, I know I look like the bad guy but I seriously think this release was just a target more to SMB than anything. IMO, this is more like a feature for those of smaller businesses because now they don’t have to go out and spend all that crazy dough on a VAAI capable array (Hooray for them :)) which begs to question….
Why do you need to enable this feature if you already leverage VAAI capable arrays?
It just seems to me that Fast Provisioning is a little pre-mature in its release. Although VCD continues to improve I think this features needs some serious improving before some bigger shops may decide to utilize it. The other down is that we have yet to see any real progress on the UNMAP problem and it’s now treated as a manual task we should run during certain times… or outages I should say. That really blows because we all know what kinds of benefits and problems thin provisioning on some array can cause. For the most part, it’s just really bad reporting… lol.
Here are some other sources I would recommend reading and I seriously think you should read them and learn for yourself if it’s really worth it. Also, be careful not to put the cart before the OX and do your homework. Some people drink the kool-aid and don’t think to question or ask “What’s really under the hood?”. Fast Provisioning should never be compared to VMware View… It’s similar but not identical.. I would definitely recommend reading Nick’s blog it opened my eyes to what he calls the “Fallacies” and of course Chris has a good read.
Well, I wasn’t sure how to name this blog as VMware continues to use all kinds of different lingos for all of their bells and whistles. I had the unique opportunity to begin working with migrating management interfaces or also know as vmkernel interfaces around from VSS to the DVS switching. This present a lot of struggles but it seems to me that VMware has really improved this functionality in the later versions of vSphere. I recall running into many kinds of issues when doing this on 4.0. So far using a vCenter 5 server with a mix of 4.1 and 5.0 host testing has proved to be seamless and non-interruptive. However, I would still highly recommend considering all your options and testing this method THOROUGHLY before ever touching production environments.
I was able migrate a single physical NIC running ESXi management from a VSS to a VDS. This video covers how I did that. The reason for the video was because I got all kinds of senseless google links when trying to search for something documented. So, I did myself a favor and published one.
Remember, this is a test and this is only applicable for me to use in a few environments. In most cases I use redundant NICs. Now the real kicker about this is that to migrate from a VDS to a VSS requires a bit more thinking and planning. Especially if you only got access to a single PNIC. Maybe I will cover that some other time… for now try to use two. Also, this may be a solution for environments running single 10GB and need to use PVLANS or centralize managment.