I am using VirtualBox in windows 8 for launching guest OS and NAT as a virtual network adapter.
i want to know whether the guest OS supports network bandwidth control(I should get a notification when data usage crosses a particular limit) or not ?
As far as I know:
Nope. VMWare on the other hand got bandwidth limiting capabilities (like throttling and introducing lag/jitter/loss.)
But bandwidth meter? No.
Use a software for that. It's called "Bandwidth meter". (It's not free, but that's the one I used and the one worked perfectly.)
And with this I totally go into SU scope: Try updating your modem software. Most new software contains a bandwidth meter feature. (In case that's why you are looking for such feature in VBox.)
Related
I have a general question. I made a VPN accessible in mobile platforms, it’s hosted on AWS and everything works fine.
The only problem is it costs a lot of money, (Amazon bill is over $1000) and not because of CPU or memory usage, which are negligible, but because of bandwidth usage.
For our Devops friends- It’s not that I need an orchestrator like Kubernetes, because it works the same way if there are 300 people connected or only 1, everything works fine on a single instance (only the bills changes)
Is there any way to reduce the cost? Did I make the VPN in the correct way? How can I reduce the bandwidth per user?
I used hosted OpenVPN servers on Amazon, Ubuntu 18.04 machine and the clients are mobile applications.
You could probably save a little bit of bandwidth (between the client and server) by enabling compression:
–compress [algorithm]
Enable a compression algorithm.The algorithm parameter may be “lzo”,
“lz4”, or empty. LZO and LZ4 are different compression algorithms,
with LZ4 generally offering the best performance with least CPU usage.
For backwards compatibility with OpenVPN versions before v2.4, use
“lzo” (which is identical to the older option “–comp-lzo yes”).
https://openvpn.net/community-resources/reference-manual-for-openvpn-2-4/
I am wondering if it is possible to limit/control ethernet upload and download speeds on specific transport layers (tcp/udp) using c++? I am trying to make a simple to use program that can control the speeds of any device that the ethernet is connected to. For example: Computer B is connected to computer A via Internet Connection Sharing, I use my program to limit computer B's download or upload speed to 120kbs (or any number i choose), with this I would also like to choose udp or tcp.
Basically, I want to create my own program similar to net limiter and other such software, but I also want to add my own features which many of which lack for my needs. These other features are easy enough, but I have no idea how to go about the actual limting process.
The way forward in the general case you ask about would be to create a virtual network adapter and all the monitored route traffic through it. Once that was done, then you can monitor streams between hosts or on specific ports.
Not an easy job... A starting point would be the Windows device driver kit.
If you were prepared to limit just one app, and could modify it, the task would be much simpler... wget and curl for example both offer limiting.
HTH, Ruth
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.
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
I'm using VMware Workstation 6.0 for simulation of tight clusters of "blades" in a "chassis". Both the host and target OSs are Linux. Each "chassis" uses a vmnet switch as a virtual backplane, to which the virtual blades connect. Other vmnet switches are used to mediate point-to-point connections between mutiple virtual ethernet adapters on each blade VM. The chassis, and thus the VMs, are brought up and shutdown rather frequently. My scripts (python) make heavy use of the VIX api, and also manipulate the .vmx config file.
What do I gain and/or lose going from VMware Workstation to ESX? Do my scripts that use the VIX api still work? Do my rather complicated virtual network topologies, with lots of vmnet switches defined as "custom", still work the same way? Is the syntax and semantics of the .vmx config file the same between Workstation and ESX?Thanks in advance for your help.
The first thing you'll gain by switching will be a substantially more powerful platform that's running directly on the bare-metal of your server.
From my experience, moving up the VMware application stack has never been problematic (Server to Workstation to ESX). However, I would verify this by exporting all of your VMs from the workstation install to an ESX install to make sure you're not seeing any 'weird' issues related to running the high-end tool from VMware.
From my [limited] experience, scripts also carry-over cleanly: each offering moving up their product line doesn't break lower-level tools, but do add substantial improvements.
You get scalability and performance.
ESX scales much better and run much faster than any of VMware desktop products like Workstation or Player.
You should not lose anything. ESXi performs all the functions that Workstation does, plus a lot more. I use ESXi at home and Workstation on my laptop.
You will gain more fine-grained control over the virtual networks, over storage, snapshots, cloning, quiescing guest OSes, and many more advanced options in ESXi configuration.
One thing to note is the considerable expense of the ESX line compared to Workstation. If you're working for a successful company, though, the cost can easily be justified as ESX is (imho) da bomb. Also, FYI, the old free VMware Server options definitely had a whole different interface.