VMware Fault Tolerance possible Tests - vmware

I have been thinking about how I can test my Fault Tolerance machines.
But I can't seem to come with a proper test.
How can I possibly calculate the time it took for VMware to switch from the primary virtual machine to the secondary one?

Ping the VM and kill the host where the primary runs, how many pings do you loose? This should give you a feeling for the time it takes vSphere to switch from the primary virtual machine to the secondary.

Related

How to change External IP of a Google Cloud VM instance to my 'normal' IP

I'd firstly like to point out that I am not an expert with computers, so if I ask any nonsensical questions, then I would hope that you would forgive me!
I have lately been using the Google cloud virtual machines. I am unsure why, but they are a lot faster than the virtual machines that I install with VirtualBox. So I have been using Google cloud virtual machines to play browser games where computer and internet speed is important. However, the browser game that I play does not permit the use of proxies/VPNs. So I quickly get banned when a Human does a manual review of my account, because these virtual machines give one of googles proxies.
So I would like to find a solution for this. Would it be possible to somehow change the virtual machine's IP to the IP that my host operating system uses?
If this is not possible, then I would appreciate if anyone could brainstorm some alternative solutions. I have thought about Residential proxies, as these proxies cannot be detected when site owners run it in one of those websites that reveal datacenter proxy users. But, these proxies cost a bit too much.
I have one final question. Why are these Google cloud virtual machines so fast in comparison to virtual machines that are manually installed?
If you use a VM without specific IP, called static IP, simply restarted the VM (perform stop and start, not a reset). The ephemeral IP will change.
Then, about speed, it's hard to answer without knowing exactly the other VM that you speak about. VMs, with the same CPU and memory, are globally equivalent. However, localisation and network can change. Google have a great network with low latency

How to restart network Interfaces on virtual machine instead of complete machine reboot/reset using pyvmomi API

I am working on a application which cloned virtual machines from a running machine on a specific event in poweredon state. The machines later communicate each other based on event and I have to fetch out (sniff) the network packets through netmon virtual machine which is routed between them but I can't do so directly, I have to reboot the guest on virtual machines manually and then I can access the network reports.
I also tried to rebootguest of vm using pyvmomi but the machine guest will take too much time to be in initial state after boot, I also do poll in loop to check virtual machine guest tool status and network status as well but nothing work, I got the empty network reports.
I did some research and found this is the right place to post this question, please let me know I am in wrong direction.

Alternative to VMWare Server on Windows Server 2008 R2

Currently we are running a VMWare Server on a Windows Server 2008 R2. The hardware specs of the machine are very good. Nonetheless, performance in virtual machines is not at all acceptable when two or more virtual machines are running at the same time (just running, not performing any CPU or disk intensive tasks).
Hence we are looking for alternatives. VMWare's website is full of buzz words only, I cannot figure out if they provide a product fitting our requirements. But alternatives from other suppliers are also welcome.
There are some constraints:
The virtualization product must run on Windows 2008 R2 - the server will not be virtualized (hence esx is excluded)
Many Virtual Machines already exist. They must be usable with the new system, or the conversion process must be simple
The virtualization engine must be able to run without an interactive user session (hence VMWare Player and VirtualBox are excluded)
It must be possible to reset a machine to a snapshot and to start a machine via command line from a different (i.e. not the host) machine (something like the vmrun command)
Several machines must be able to run in parallel without causing an enormous drop in performance
Do you have some hints for that?
Have you considered Hyper-V (native hypervisor in Windows)?
However I would suggest troubleshooting the performance issues (the most common is not enough RAM for VM or host - which result in paging and poor performance)
Though I could not find a real alternative to VMWare Server with the constraints given, I could at least speed the performance up:
changing the disk policies from "Optimize for safety" to "Optimize for performance" reduced the time of most build projects by a third
installing IP version 6 protocol on the XP machines typically brought another 10%
The slowest integation testing project (installation of Dragon Naturally Seaking 12) is now done in 20 minutes instead of 2h20min.
Still, when copying larger files from the host to the virtual machine, performance is inacceptable - while copying them from a different VM on the same host works far better...
I would still consider esxi and 2008 on top of that if i would be in your place.
We used vmware server and performance is simply not comparable to esxi especially if you are using IO intensive applications.

Is there a way for the cache to stay up without timeout after crash in AppFabric Cache?

First my setup that is used for testing purpose:
3 Virtual Machines running with the following configuration:
MS Windows 2008 Server Standard Edition
Latest version of AppFabric Cache
Each one has a local network share where the config file is stored (I have added all the machines in each config)
The cache is distributed but not high availibility (we don't have Enterprise version of Windows)
Each host is configured as lead, so according to the documentation at least one host should be allowed to crash.
Each machine has the website I testing installed, and local cache configured
One linux machine that is used as a proxy (varnish is used) to distribute the traffic for testing purpose.
That's the setup and now on to the problem. The scenario I am testing is simulating one of the servers crashing and then bring it back in the cluster. I have problem both with the server crashing and bringing it back up. Steps I am using to test it:
Direct the traffic with Varnish on the linux machine to one server only.
Log in to make sure there is something in the cache.
Unplug the network cable for one of the other servers (simulates that server crashing)
Now I get a cache timeout and I get a service error. I want the application to still be up on the servers that didn't crash, and it take some time for the cache to come back up on the remaining servers. Is that how it should be? Plugging the network cable back in and starting the host cause a similar problem.
So my question is if I have missed something? What I would like to see happen is that if one server crashes the cache should still remaing upp since a majority of the leads are still up, and starting the crashed server again should bring it back gracefully into the cluster without any causing any problems on the other hosts. But that might no be how it works?
I ran through a similar test scenario a few months ago where I had a test client generating load on a 3 lead-server cluster with a variety of Puts, Gets, and Removes. I rebooted one of the servers multiple times while the load test was running and the cache stayed online. If I remember correctly, there were a limited number errors as that server rebooted, but overall the cache appeared to remain healthy.
I'm not sure why you're not seeing similar results, but I would try removing the Varnish proxy from your test and see if that helps.

How to keep a VMWare VM's clock in sync?

I have noticed that our VMWare VMs often have the incorrect time on them. No matter how many times I reset the time they keep on desyncing.
Has anyone else noticed this? What do other people do to keep their VM time in sync?
Edit: These are CLI linux VMs btw..
If your host time is correct, you can set the following .vmx configuration file option to enable periodic synchronization:
tools.syncTime = true
By default, this synchronizes the time every minute. To change the periodic rate, set the following option to the desired synch time in seconds:
tools.syncTime.period = 60
For this to work you need to have VMWare tools installed in your guest OS.
See http://www.vmware.com/pdf/vmware_timekeeping.pdf for more information
according to VMware's knowledge base, the actual solution depends on the Linux distro and release, in RHEL 5.3 I usually edit /etc/grub.conf and append this parameters to the kernel entry: divider=10 clocksource=acpi_pm
Then enable NTP, disable VMware time synchronization from vmware-toolbox and finally reboot the VM
A complete table with guidelines for each Linux distro can be found here:
TIMEKEEPING BEST PRACTICES FOR LINUX GUESTS
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006427
I'll answer for Windows guests. If you have VMware Tools installed, then the taskbar's notification area (near the clock) has an icon for VMware Tools. Double-click that and set your options.
If you don't have VMware Tools installed, you can still set the clock's option for internet time to sync with some NTP server. If your physical machine serves the NTP protocol to your guest machines then you can get that done with host-only networking. Otherwise you'll have to let your guests sync with a genuine NTP server out on the internet, for example time.windows.com.
Something to note here. We had the same issue with Windows VM's running on an ESXi host. The time sync was turned on in VMWare Tools on the guest, but the guest clocks were consistently off (by about 30 seconds) from the host clock. The ESXi host was configured to get time updates from an internal time server.
It turns out we had the Internet Time setting turned on in the Windows VM's (Control Panel > Date and Time > Internet Time tab) so the guest was getting time updates from two places and the internet time was winning. We turned that off and now the guest clocks are good, getting their time exclusively from the ESXi host.
In my case we are running VMWare Server 2.02 on Windows Server 2003 R2 Standard. The Host is also Windows Server 2003 R2 Standard. I had the VMware Tools installed and set to sync the time. I did everything imaginable that I found on various internet sites. We still had horrendous drift, although it had shrunk from 15 minutes or more down to the 3 or 4 minute range.
Finally in the vmware.log I found this entry (resides in the folder as the .vmx file):
"Your host system does not guarantee synchronized TSCs across different CPUs, so please set the /usepmtimer option in your Windows Boot.ini file to ensure that timekeeping is reliable. See Microsoft KB http://support.microsoft.com/kb... for details and Microsoft KB http://support.microsoft.com/kb... for additional information."
Cause: This problem occurs when the computer has the AMD Cool'n'Quiet technology (AMD dual cores) enabled in the BIOS or some Intel multi core processors. Multi core or multiprocessor systems may encounter Time Stamp Counter (TSC) drift when the time between different cores is not synchronized. The operating systems which use TSC as a timekeeping resource may experience the issue. Newer operating systems typically do not use the TSC by default if other timers are available in the system which can be used as a timekeeping source. Other available timers include the PM_Timer and the High Precision Event Timer (HPET).
Resolution: To resolve this problem check with the hardware vendor to see if a new driver/firmware update is available to fix the issue.
Note The driver installation may add the /usepmtimer switch in the Boot.ini file.
Once this (/usepmtimer switch) was done the clock was dead on time.
This documentation solved this problem for me.
The CPU speed varies due to power saving. I originally noticed this because VMware gave me a helpful tip on my laptop, but this page mentions the same thing:
Quote from : VMWare tips and tricks
Power saving (SpeedStep, C-states, P-States,...)
Your power saving settings may interfere significantly with vmware's performance. There are several levels of power saving.
CPU frequency
This should not lead to performance degradation, outside of having the obvious lower performance when running the CPU at a lower frequency (either manually of via governors like "ondemand" or "conservative"). The only problem with varying the CPU speed while vmware is running is that the Windows clock will gain of lose time. To prevent this, specify your full CPU speed in kHz in /etc/vmware/config
host.cpukHz = 2167000
VMware experiences a lot of clock drift. This Google search for 'vmware clock drift' links to several articles.
The first hit may be the most useful for you: http://www.fjc.net/linux/linux-and-vmware-related-issues/linux-2-6-kernels-and-vmware-clock-drift-issues
When installing VMware Tools on a Windows Guest, “Time Synchronisation” is not enabled by default.
However – “best practise” is to enable time synch on Windows Guests.
There a several ways to do this from outside the VM, but I wanted to find a way to enable time sync from within the guest itself either on or after tools install.
Surprisingly, this wasn’t quite as straightforward as I expected.
(I assumed it would be posible to set this as a parameter / config option during tools install)
After a bit of searching I found a way to do this in a VMware article called “Using the VMware Tools Command-Line Interface“.
So, if time sync is disabled, you can enable it by running the following command line in the guest:
VMwareService.exe –cmd “vmx.set_option synctime 0 1″
Additional Notes
For some (IMHO stupid) reason, this utility requires you to specify the current as well as the new value
0 = disabled
1 = enabled
So – if you run this command on a machine which has this already set, you will get an error saying – “Invalid old value“.
Obviously you can “ignore” this error when run (so not a huge deal) but the current design seems a bit dumb.
IMHO it would be much more sensible if you could simply specify the value you want to set and not require the current value to be specified.
i.e.
VMwareService.exe –cmd “vmx.set_option synctime <0|1>”
In Active Directory environment, it's important to know:
All member machines synchronizes with any domain controller.
In a domain, all domain controllers synchronize from the PDC Emulator (PDCe) of that domain.
The PDC Emulator of a domain should synchronize with local or NTP.
It's important to consider this when setting the time in vmware or configuring the time sync.
Extracted from: http://www.sysadmit.com/2016/12/vmware-esxi-configurar-hora.html
I added the following job to crontab. It is hacky but i think should work.
*/5 * * * * service ntpd stop && ntpdate pool.ntp.org && service ntpd start
It stops ntpd service updates from service and starts ntpd again