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.