Several Host Isolation

Imagine a scenario where we had a HA of four nodes cluster spread on a campus with two nodes in one place and two in the other. What would the host isolation response if the network connection between the two sites has been lost?

If we lose a host then the TI is known to be isolated after 12 years and then failed aftet 15s. If we lose two, however, nobody is isolated and I am assuming that nothing happens.

Now; Imagine that we have warehouses of data which are all shared, but some are in one site and some are in the other. Guests running on local data warehouses would be unaffected. Guests who are running on data warehouses remote fails. The question is: what will happen to the hosts failed?

Thank you

Warren Barnes

Before you answer this in detail, I want to make sure I'm clear on my assumptions:

1. There are 4 hosts in the cluster, two on each side of the stretch. If this is the case, then all 4 hosts are primary. (The first 5 guests in any cluster are primary, so you get only secondary when there are 6 or more hosts).

2 If the network fails between the two sites, storage will be split-brain as well? I guess that Yes, based on one of your comments.

If, in view of the #1 site hosts A and B, and site #2 a hosts C a D...

If, after the split between site 1 and 2, and B can still heart rhythm with each other, and C and D can pulse between them then there is no answer tried insulation. Answers insulation kick only in when a host can not with any of the other primitives of the heart rate, and it can also ping the address of isolation (usually the gateway (s)) for networks that host is on.

So what happens is that A & B site 1 to conclude that C & D at site 2 have failed. And vice versa. A and B will try to power - on the virtual machines that are running on C and D, even for C & D - they will try and power on virtual machines that have been on A and b. Now, because the storage of some virtual machines can be found at site 1 and storage other virtual machines are at site 2, some of the power-ons may fail because the storage is not accessible. But as A & B will attempt to power on the set of the VMS C & D and C & D will attempt to power on the set of virtual machines of A & B (that means that admission control allows all of these power-ons) then each VM will end up under tension correctly on each site 1 or site 2.

Now for the ugly part - if any of the VMS to site 1 lost their storage in the score, or vice versa, then the vmware-vmx process who represent these virtual machines always operate on one or more hosts on the side of the partition that has lost the storage and there is now a process vmware-vmx representative the same virtual machine running on a host across the partition that has now acquired a lock on this VM. None of this is a problem until the partition joined. This is so the behavior described by Elisha happens - that is to say the virtual machine appears to bounce back between the two hosts until the answer to the question on the lock lost by pointing the VC client directly to the host. And as he pointed out, the question will be auto-répondu by VC to vSphere 4.0 U2 and above.

-Ron

Tags: VMware

Similar Questions

  • HA retry time host isolation?

    Suppose the network breaks for some a host and host isolation response is stopped. After 12 seconds he will make his test of isolation, then will launch to stop the virtual machines running on the host.

    Other hosts will detect the host missing after 15 seconds and try to start them. However, because virtual machines very, probably not even to stop the locks on files are in place. Let's say that according to the workload inside the guest, it will take all of 20 seconds to several minutes to make a gradual stop. (I know there is a sunset that goes off after 5 minutes).

    But my question is, how long and how often other hosts will try to restart the VMs system which vmdk files become available one after the other?

    Duncan Epping describes the behavior of the http://www.yellow-bricks.com/2010/06/30/how-does-das-maxvmrestartcount-work/ reboot

    André

  • OS command to several hosts of licensing issue of library work

    Hi all

    Is creating jobs and running OS command to several hosts draws from employment requires an additional license in grid 12 c?

    Thank you in advance!

    Jeffrey

    Hello Jeff,.

    No it is not necessary.

    Sincere greetings,

    Ansari

  • Deploy multiple virtual machines on several hosts evenly?

    Hello people!

    I wrote a small script to deploy many virtual machines on several hosts at random.

    But I would rather deploy a virtual machine to each host in a table and then start over again until the number of virtual machines to deploy exhausted.  Distribution of the burden of deployment as evenly as possible.

    Anyone have a suggestion?  Example of nested loops?

    PowerShell beginner, here.

    Thank you

    romatlo

    One way to do this is with the modulo operator (%), something like this

    $numVMs = 11

    $tgtEsx = get-Cluster "Westcreek | Get-VMHost-name z420 *.

    1.. $numVMs | %{

    [New-VM-name 'Test $($_)' $tgtEsx[$_%$tgtEsx.Count - VMHost]

    }

  • The host Isolation response

    Hello

    Can I know what is "host isolation response '.

    Thank you

    Prashant

    In short: ESXi hosts running in a HA cluster communicate with each other by sending heartbeats. If a host does not receive the heartbeat of the other hosts more and also cannot each address isolation it triggers the response of isolation.

    For more information on HA, please take a look at http://www.yellow-bricks.com/vmware-high-availability-deepdiv/

    André

  • Host isolation response Question

    So, there were a few questions recently in our company on the host isolation response works in vCenter server 4.1.  Given the descriptions on the options available to the virtual machine power on or at the bottom of the current virtual machine, how HA determines that an isolated host is really isolated and running compared to completely failed (offline)?

    Can someone explain in detail a bit more technical that what the VMware article pages kb explain works host isolation response?

    Reading of how insulation host configurations can be defined, if you set the parameters of insulation "leave the virtual machine running", in case of total failure of host (offline) the other cluster hosts not to try the virtual machine online on another host?  And it is recommended to set the response of isolation to "turn off" so that the other hosts in the cluster can bring the virtual machine online?

    I still don't understand how a host can be determined as 'remote' from the 'offline '.  Isolation is simply the communications network have failed and are virtual machine always happily along on the isolated host.  A host simply default and past in offline mode (power failure Physics for example) is a completely different scenario.  Locks are not released correctly (not be able to any type of response of isolation configuration) and the virtual machine is not running on the host offline

    To the HA cluster if communication is lost to a node of the cluster assumes that the node has failed and will be Jean-Marie to restart the virtual machine on nodes in the cluster of rremaining - locks are constantly updated so if the host is not responding is rather isolated that failed he'll again be refreshing locks on the VMDK files. and virtual machines does not start - it is this feature which allows the AP to work - because with what you describe HA would never--work

    In the scenario were the host disconnects and the virtual machine is not running and the response of isolation is set to "leave the virtual machine running" how other hosts in the cluster determin the host is really low?

    The other guests guess always the isolated host is really down and try to restart the VMs - isloated host system is the machine that will follow response of isolation parameters - either the vms on power or powered by letting off the coast

  • host isolation question

    When ESX host is isolated from the network? Once, he loses the Service Console or the management network WLAN?

    Network isolation occurs when:

    • Host online cannot receive heartbeat of the other primary guests AND

    • The impossible host isolation ping address

    Although your always up and running Layer2 switch and your dependent hos-to-host communication on the basis of the existence, of course network isolation switches will happen.

    http://www.no-x.org

  • The host Isolation response / loss of iSCSI connectivity - what if scenario

    The other thread on automatic shutdown made me think at our facility:

    1. when our building lost power, we lose cooling and networking, but remains on our servers/UPS systems, as they are connected to a backup generator.

    2 Yah, so, it's not good, cooling is lost, and the servers are will heat up, then we must begin to stop them until the coolant has been restored.

    Our 2 ESX systems connect to our SAN via iSCSI - with the lost power, the SAN and the ESX servers are no longer speaks, so I turned off our ESX servers, until the coolant has been restored, as no negative consequences on the correct virtual machines?

    With the connection of networking\iSCSI lost between ESX servers and SAN, that State will be our being for most Windows virtual machines?  They're going to be trashed?  Or ESX has some kind of verification in place for this type of ailment?

    In our current situation, what would be the recommended host Isolation response parameter?

    Thanks for any idea,

    Chad

    Our 2 ESX systems connect to our SAN via iSCSI - with the lost power, the SAN and the ESX servers are no longer speaks, so I turned off our ESX servers, until the coolant has been restored, as no negative consequences on the correct virtual machines?

    It shouldn't - but this will depend on all wht that the VM, the operating system and the application were doing at the time of the accident-

    With the connection of networking\iSCSI lost between ESX servers and SAN, that State will be our being for most Windows virtual machines? They're going to be trashed? Or ESX has some kind of verification in place for this type of ailment?

    ESX does not check this condition - from your virtual machines is on the iSCSI SAN you will find crashed.

    If you find this or any other answer useful please consider awarding points marking the answer correct or useful

  • several hosts aaa server for authentication vpn

    ASA5510 - 7.2 (1)

    Using the following configuration, I try to have several radius servers configured for authentication backup in case of failure of the primary vpn. This seems to work ok. But once the main server upward when the asa will begin to use it again. The release of "aaa-Server 172.25.4.20 host" said

    Server status: FAILURE, server disabled at 08:04:25.

    How do reactivate you it?

    RADIUS protocol AAA-server adauth

    adauth AAA-server 172.25.4.20

    key *.

    authentication port 1812

    accounting-port 1813

    adauth AAA-server 172.25.4.40

    key *.

    authentication port 1812

    accounting-port 1813

    tunnel-group group general attributes

    address pool pool

    authentication-server-group adauth

    by default-group-policy

    You can add the option in the Group aaa-server:

    "reactivation in timed mode.

    This causes a dead server is added to the pool after 30 seconds.

    The following link has some good info on the options available. I suggest looking for the doc for the "reactivation".

    http://www.Cisco.com/univercd/CC/TD/doc/product/multisec/asa_sw/v_7_2/cmd_ref/crt_711.PDF

    -Eric

    Be sure to note all the useful messages.

  • vCenter 6 web gui - host isolation response

    Hello

    I was looking at the option of isolation of host and then noticed that he not there no "leave it on" option on vcenter 6 web gui (version 6.0.0 2656761). However, "leave it on" option is still available on the client. As you can see from the screenshots, I chose the option "leave on" on the heavy and used customer "turn off and restart the virtual machines ' option on web gui.

    I really appreciate if someone provides the details to clarify my confusion because I'm not sure what settings will apply in case of isolation of the host.


    Thank you

    AFAIK the "leave it powered on" in c# client is now called as "Disabled" in the Web Client, which means nothing do, don't react not if the host gets isolated.

    You say that you set the value "leave powered we" in c# client and then when you check the settings for the cluster in the Web Client, it displays "Power Off and restart VM?

    If so, no refreshing or reconnect to the web client result by displaying "Disabled" in the web client?

    I hope this helps.

  • Host Isolation response - VM Shutdown / Restart

    Gents,

    I couldn't find answer to my question myself so maybe you can help me.

    Let's say we have cluster HA VSphere 4.1 with the default settings. On hosts loses the connection to the network and all the HA primary agents start 15 sec count down. The host of problem also begins his 15 sec timer and after 12 seconds, it tries to ping the default gateway and does not answer. So he decides that he is isolated. If the network connection is not restored within 15 s primary HA officers decide that host problems failed and try to restart the virtual machines, but they can do VMS files are always locked by host problem which just initiated the process of virtual machine downtime after 15 s time of isolation.

    So my question is how that VMs are restarted then if they are not be restarted the first time? Primary HA officers constantly try to restart on alternate hosts?  They try always to restart virtual machines even if the host of the problem can't stop for 300 s and then power off? This missing part of information is really boring

    Would be very grateful for any useful information.

    http://www.yellow-bricks.com/2010/06/30/How-does-das-maxvmrestartcount-work/

    All this kind of thing is also explained by the way in my next book! Should be available through my blog in a week.

    Duncan

    VMware communities user moderator | VCDX

    -

  • HA sensitivity of host isolation

    Hello

    I was wondering if it is configurable to meanings?

    When you test the abduction of a switch of my kernel stack, I found that battery restarted in response, resulting in a failure full of about a minute.  This is why I really need to configure somehow HA to react only after, say, five minutes for the isolation of the host.

    Thank you very much

    As I understand it, das.failuredetectiontime should be what you are looking for.

    See HA Deepdive for more details

    André

  • Response of host Isolation and HA

    I was wondering what happens if your cluster 'Response of Isolation host' is set to "leave VM under tension" and you actually have a host fail.  HA will be able to distinguish between a host that is not visible on the network and let these VM under tension and a host that is down and restart these VM elsewhere?

    Thank you

    Yes, a failure of HA, other members can resume the lock that existed prior to the failure of the host for the virtual machine it was running.  In the case of a response of isolation, these locks are not erased, so when other hosts are trying to take over the lock, they are being denied and therefore stay up to the virtual machine and running on the response of isolated, as opposed to the caught locks if the host fails.

    Not the best description and I'm sure I've missed a step or two, but for all purposes, Yes, HA can make a difference between failure and isolation.

    -KjB

  • cRIO several hosts

    Hi all

    is it possible to have a target of crio running a central VI that exchanges data with the host screw turns on different hosts?

    Thank you very much

    Harry

    You must create an exe of the target code and deploy it to the target then run only the codes of the host on different computers. Make sure that you don't have any dependency of the target code in your host code. The error you posted will happen only when you are already running a code on the target, and if you try again to deploy the code in the same target of another computer.

  • Activation of the NAC HA puts several hosts and ASA with processor clocked at 100%

    I installed a NAC Manager and a NAC server in OOB without any problems, but when I configured the AP (high availability) with another server, my ASA and several guests in my network started work ant 100% of the cpu.

    I tried to configure each interface of the NAC on a single DMZ and the problem stops there.

    -That someone had this problem (NAC version 4.7)

    TKX

    Miguel Amaral

    Hello Miguel.

    When I started a NAC InBand HA solution I had a similar problem that I solved the heart rate HA configuration to use ETH0 just instead use ETH0 and ETH1.

    Best regards

    Luciano Carvalho

Maybe you are looking for

  • Adobe flash 11 is installed (?) but not detected

    When I try to use google street view in firefox v. 24 for linux, I get a balloon saying that I have flash player 10 or higher. I tried to install the latest version of flash. When I restarted firefox it says that he was installing new plugins, it see

  • Tecra A10 - how to change the RAM?

    Hello I was wondering I just bought a new Toshiba Tecra A10, I just wondered how the change of the RAM, it comes with 1 GB of Ram I want upgraded to 2 GB or 4 GB. The RAM slots are located at the rear of the Machine or below the keyboard? Any help wi

  • Stor.E TV + White Screen of Death"

    My box packed yesterday, surprisingly 1 day after her 1st birthday! All I get now is a white glitter on the front panel display. Means that the box has not experienced a catastrophic failure, or did I suspect a blockage of the software. If it is the

  • How can I call a stage, which is in a sous-suite, of a different sous-suite

    Hi, could someone me, please? How can I call a stage, which is in a sous-suite, of a different sous-suite. For example: Two sub sequence, is called, it is called B. In the order B, there is a step called BStep. In a sequence, there is a stage called

  • Do I need a Windows service?

    I have to run an .exe file built with LV, using the Exec VI system. I want the called application to run without front. In the application builder there is no option to hide the front panel.How can I solve the problem? Can I create a windows service