I had a question last week around HA’s datastore heartbeating, the question was if datastore heartbeating still worked if you only have 1 datastore in your environment. I can understand where the question comes from as HA throws this error that you need to have 2 datastores at a minimum for HA datastore heartbeating to function correctly. I want to point out that even though HA says that 2 datastores is the minimum, even when only one datastore is available it will be used for heartbeat purposes. Yes this error will be there on your cluster, and yes you can suppress it using “das.ignoreInsufficientHbDatastore“. I figured others might be hitting the same error and have the same question so why not document it?!
Server
Minimum bandwidth requirements per concurrent vMotion?
I have been digging for a long time now to figure out what the minimum bandwidth requirements are per concurrent vMotion. After a long time I finally managed to get a statement. In the past the statement was made that 622Mbps was the minimum required bandwidth for vMotion, it appears that this is incorrect for vSphere 5.0 and higher. With vSphere 5.0 a new feature called Stun During Page Send (SDPS) was introduced and this has decreased the bandwidth requirements from 622Mpbs down to 250Mbps per concurrent vMotion.
Always nice to know right?!
ESXi “Management traffic” tickbox, what does it do?
I have seen this popping up various times over the last few years. That little tickbox on your VMkernel NIC that says “Management traffic” (aka management network) what is it for? What if I untick it, will SSH to that VMkernel still work? Will the HA heartbeat still work? Can I still ping the VMkernel NIC? Those are all questions I have had in the past, and I can understand why… I would say that the term “Management traffic” is really really poorly chosen, but why?
The feature described as “Management traffic” does nothing more than enabling that VMkernel NIC for HA heartbeat traffic. Yes that is it. Even if you disable this feature, management traffic, you can still use the VMkernel’s associated IP address for adding it to vCenter Server. You can still SSH that VMkernel associated IP address if you have SSH enabled. So keep that in mind.
Yes I fully agree, very confusing but there you have it: the “management traffic” enables the HA heartbeat network, nothing more and nothing less.
My VMworld US 2013 schedule…
It seems that the dust has finally settled, it is clear what my VMworld schedule will look like. Well for now at least, as I will expect some “one on one” slots to be added, as part of the Expert track. If one of the sessions fills up there might also be a repeat, who knows… I will use this blogpost though to keep track of my agenda, for those who care:
- Monday August 26th, 16:00 / 17:00 – BCO1000-GD – High Availability Futures with Keith Farkas and Duncan Epping
- Tuesday August 27th, 11:00 / 12:00 – VSVC4569 – Ask the Expert vBloggers with Rick Scherer, William Lam, Scott Lowe, Vaughn Stewart and Duncan Epping
- Wednesday August 28th, 08:30 / 09:30 – BCO4872 – Operating and Architecting a vSphere Metro Storage Cluster based infrastructure with Lee Dilworth and Duncan Epping
I had the question various times if there will be a chance to meet up. Typically my schedule is packed with various customer meetings, however as mentioned there are the “one on one” slots that can be signed up for during VMworld. Also, feel free to come up to me when you see me walking in the hallway / after my session / at a social event. Don’t be afraid, I love to talk to readers and understand what keeps you guys up at night. (No, I am not as grumpy/grouchy in real life as I sometimes seem to be on twitter.) Talking about Social Events, which seems to become a bigger and bigger part of VMworld every year, these are the ones I am aiming to attend:
- Saturday: vBeers, Cheiftain
- Sunday: VMworld Welcome Reception
- Monday: Nimble Storage, VMUG Reception
- Tuesday: PernixData, CloudPhysics, VMware CTO Event, Lightspeed, Veeam
- Wednesday: VMworld Party AT&T Park
Yes, busy times ahead… Now lets see if I can finalize that presentation.
PS: If you don’t prefer using the VMworld.com website, there is an app for Android and iOS. I just installed the iOS app, you never know when you need it right!
Startup News Flash part 1
I am on PTO this week so have tried to avoid spending time behind my mac/iPhone/iPad, well tried I guess… It is difficult as most of you probably know and have realized. While on vacation a couple of interesting things happened, hence this Startup New Flash blog post. The primary focus of this article is Startup news / Flash-related news. Preferably in the storage/flash space. This can be flash caching, flash arrays, hybrid arrays, flash drives… you name it! I guess “new technologies from old companies” would even fit. Will try to make this a regular thing… Or at least use the same title when there is something flashy announced or worth calling out.
For those who have been living under a rock the last week, besides introducing a brand new logo, PernixData announced general availability of FVP 1.0. On Monday my RSS reader was filled with Pernix related articles, and I was almost at the point of muting “Pernix” on twitter. So why the excitement, what did they announce? Hopefully, most of you have read my article on Pernix, or have been following Frank’s series of articles. I guess everyone is aware that Pernix offers a hypervisor-based flash virtualization platform. Meaning that their solution is installed as a “vib” within ESXi, indeed not an appliance-based approach. But others are doing this as well, so what is so unique about it? Write-back caching… Clustered write-back caching that is, so guaranteeing consistency of your IO. In other words, when within FVP you enable “write-back” caching, you can select how many relicas of the IO you want. (Currently, it ranges from 0 to 2.) Pricing for the enterprise solution was also announced, $ 7500,- per host. The announcement mentions there will be a different SKU for SMB, so looking forward to hear the details on that. One thing which I didn’t know is that Pernix also has optimization for View environments, it contains a form of “dedupe” for the base images… Frank revealed this on the APAC podcast (episode 77) he was on, hosted by Mike Laverick. (Recommend listening to it.) All in all an exciting and unique 1.0 release… I guess you might wonder where I think they should focus on, for me that would be NFS support and potentially support for other hypervisors, but if I recall correctly Satyam or Frank mentioned that those are being worked on.
Diablo announced Memory Channel Storage (MCS). The next logical step if you ask me when it comes to reducing latency and increasing bandwidth. MCS basically brings flash closer to your CPU by leveraging the memory bus instead of PCIe/SAS/SATA. Interesting concept, something worth exploring. Especially considering you can present it as either normal memory (how about TBs of memory for a fraction of the price?) or as a block device. This means that you could potentially use Diablo as a target for a flash caching solution. One of the benefits many people listed is that this solution would be very useful in blade environments or hyperconverged due to the fact that it eliminates the need for a PCIe slot or a disk slot… I guess that is somewhat true, in many of those cases the number of memory slots will also be limited so it doesn’t really solve those types of constraints immediately. Nevertheless, an interesting solution which is worth exploring and definitely offers new opportunities.
Another interesting announcement came from a startup called Crossbar. Crossbar came out of stealthmode this week, and is working on RRAM. With 20x faster write performance at 20x lower power consumption and much higher capacity density compared to best-of-breed flash solutions you can understand why people are excited about Crossbar. The market opportunity is huge here, and various companies have been working on it… So far not many have been able to execute on it at scale, so congrats to Crossbar, and definitely a company and a solution to keep your eye on. I know I will, I have already added them to my twitter startup watch list.