vSphere 5.1 Clustering Deep Dive promotion & major milestone

This week when looking at the sales numbers of the vSphere Clustering Deep Dive series and Frank and I noticed that we hit a major milestone! In September 2014 we passed the 45000 copies distributed of the vSphere Clustering Deep Dive. Frank and I never ever expected this or even dared to dream to hit this milestone.

When we first started writing the 4.1 book we had discussions around what to expect from a sales point of view and I recall having a discussion with Frank around the sales number, Frank said he would be happy with 100 and I said well 400 would be nice. Needless to say we reset our expectations many times since then… We didn’t really follow it closely in the last 12-18 months, and as today we were discussing a potential update of the book we figured it was time to look at the numbers again just to get an idea. 45000 copies distributed (ebook + printed) is just remarkable, and we are very humbled, baffled and honoured!

We’ve noticed that the ebook is still very popular, and decided to do a promo. As of Monday the 13th of October the 5.1 ebook (kindle) will be available for only $ 0.99 for 72 hours, then after 72 hours the price will go up to $ 3.99 and then after 72 hours it will be back to the normal price. Make sure to get it while it is low priced!

You can pick it up here on Amazon.com! The only other kindle store we could open the promotion up for was amazon.co.uk, so that is also an option.

das.maskCleanShutdownEnabled is set to true by default

I had a couple of questions on the topic of das.maskCleanShutdownEnabled today. For those who have not read the other articles I wrote about this topic, this is in short what it does and why it was introduced and how I explained it in an email today:

When a virtual machine is powered off (or shut down) by a user a property is set to true named runtime.cleanPowerOff”. To vSphere HA this indicates that the virtual machine was powered off by a user and as such when a host fails it knows that for this virtual machine it doesn’t need to take action. By default this property is set to true. If for whatever reason the virtual machine is killed by ESXi than this property is set to false.

vSphere HA provides the ability to respond to a storage failure (PDL). When a PDL occurs it can kill a virtual machine and then restart the virtual machine. However, runtime.cleanPowerOff” default is “true” and vSphere HA cannot access the datastore (PDL remember) to change the property! So this means if the VM is killed after the PDL, then it won’t be restarted as HA assumes it was cleanly powered off.

This is where das.maskCleanShutdownEnabled comes in to play. By setting this to “true”, vSphere HA assumes that VM is not cleanly powered off. Only when you cleanly power it off the property is set. In other words, In a PDL situation it will now restart the VM even though the datastore was unavailable when the VM was killed!

Back to the original question, what is das.maskCleanShutdownEnabled set to in 5.1 and later? Do you need to set it manually? No you do not, by default it is set to true! So when you configure a cluster, be aware of this… Especially in a stretched cluster environment where a PDL scenario is not unlikely.

** do not forget to also set terminateVMonPDL described in this blog post if you want VMs to be automatically killed when a PDL occurs! **

VPLEX Geosynchrony 5.2 supporting up to 10ms latency with HA/DRS

I was just informed that as of last week VPLEX Metro with Geosynchrony 5.2 has been certified for a round trip (RTT) latency up to 10ms while running HA/DRS in a vMSC solution. So far all vMSC solutions had been certified with 5ms RTT and this is a major breakthrough if you ask me. Great to see that EMC spent the time certifying this including support for HA and DRS across this distance.

Round-trip-time for a non-uniform host access configuration is now supported up to 10 milliseconds for VPLEX Geosynchrony 5.2 and ESXi 5.5 with NMP and PowerPath

More details on this topic can be found here:

ESXi DCUI Shutdown vs vCenter Shutdown of a host

Today on the community forums someone mentioned he had shutdown his host and that he expected vSphere HA to restart his virtual machines. For whatever reason he got in a situation where all of his VMs were still running but he couldn’t do much anymore with them and as such he wanted to kill the host so that HA could safely restart the virtual machines. However when he shutdown his host nothing happened, the VMs remained powered off. Why did this happen?

I had seen this before in the past, but it never really sunk in until I saw the questions from this customer. I figured I would test it just to see what happened and if I could spot a difference in the vSphere HA logs. I powered on a VM on one of my hosts and moved off all other VMs. I then went to the DCUI of the host and gave a “shutdown” using F12. I tailed the FDM log on one of my hosts and spotted the following log message:

2014-04-04T11:41:54.882Z [688C2B70 info 'Invt' opID=SWI-24c018b] [VmStateChange::SavePowerChange] vm /vmfs/volumes/4ece24c4-3f1ca80e-9cd8-984be1047b14/New Virtual Machine/New Virtual Machine.vmx curPwrState=unknown curPowerOnCount=0 newPwrState=powered off clnPwrOff=true hostReporting=host-113

In the above scenario the virtual machine was not restarted even though the host was shutdown. I did the exact same exercise again, but only this time I did the shutdown using the vCenter Web Client. After I witnessed the VM being restarted I also noticed a difference in the FDM log:

2014-04-04T12:12:06.515Z [68040B70 info 'Invt' opID=SWI-1aad525b] [VmStateChange::SavePowerChange] vm /vmfs/volumes/4ece24c4-3f1ca80e-9cd8-984be1047b14/New Virtual Machine/New Virtual Machine.vmx curPwrState=unknown curPowerOnCount=0 newPwrState=powered on clnPwrOff=false hostReporting=host-113

The difference is the power-off state that is reported by vSphere HA. In the first scenario the virtual machine is marked as “clnPwrOff=true” which basically tells vSphere HA that an administrator has powered off the virtual machine, this is what happened when “shutdown” was initiated through the DCUI and hence no restart took place. (It seems that ESXi initiates a shutdown of all running virtual machines.) In the second scenario vSphere HA reported that the VM was not cleanly powered off (“clnPwrOff=false”), and as such it restarted the virtual machine as it assumed something bad had happened to it.

So what did we learn? If you, for whatever reason, want vSphere HA to restart your virtual machines which are currently running on a host that you want to shutdown, make sure that you use the vCenter Web Client instead of the DCUI!

Disclaimer: my tests were conducted using vSphere 5.5 Update 1. I believe that at some point in the past “shutdown” via the DCUI would also allow HA to restart the VMs. I am now investigating why this has changed and when. When I find out I will update this post.

Startup News Flash part 16

Number 16 of the Startup News Flash, here we go:

Nakivo just announced the beta program for 4.0 of their backup/replication solution. It adds some new features like: recovery of Exchange objects directly from compressed and deduplicated VM backups, Exchange logs truncation, and automated backup verification. If you are interested in testing it, make sure to sign up here. I haven’t tried it, but they seem to be a strong upcoming player in the backup and DR space for SMB.

SanDisk announced a new range of SATA SSDs called “cloudspeed”. They released 4 different models with various endurance levels and workload targets, of course ranging in sizes from 100GB up to 960GB depending on the endurance level selected. Endurance level ranges from 1 up to 10 full drive writes per day. (Just as an FYI, for VSAN we recommend 5 full drive writes per day as a minimum) Performance numbers range between 15k to 20k write IOps and 75 to 88K read IOps. More details can be found in the spec sheet here. What interest me most is the FlashGuard Technology that is included, interesting how SanDisk is capable of understanding wear patterns and workloads to a certain extend and place data in a specific way to prolong the life of your flash device.

CloudPhysics announced the availability of their Storage Analytics card. I gave it a try last week and was impressed. I was planning on doing a write up on their new offering but as various bloggers already covered it I felt there was no point in repeating what they said. I think it makes a lot more sense to just try it out, I am sure you will like it as it will show you valuable info like “performance” and the impact of “thin disks” vs “thick disks”. Sign up here for a 30day free trial!