How about running a linux application on windows platform without any OS virtualization.
Lets say we have an linux software installed on windows machine which can run successfully on windows with below mentioned approach:
A normal windows application runs on windows by creating a virtual address space on any Operating system. Program loader loads required libraries for the application from physical drive onto virtual memory address space. All those libraries related to application gets loaded when required by using File System APIs.
Now lets go in different way, instead of creating a virtual address space on local system, we can create a process address space on different machine which is capable to run the application. In our case, create address space for linux application on remote linux machine instead of local windows machine. All file system access can be grab on remote machine and transferred to local windows machine. In this way linux application located on local windows
machine, creates process address space on remote linux machine, access file system on local windows machine. All file system related apis can be remoted and routed to local machine. Linux application UI can be captured on linux machine and sent for display on local windows machine.
In this way different platform applications can be run on other platform as well without need of OS virtualization. What is your opinion on this approach and how much it is feasible. Is there any big fault in this approach which makes this approach non-feasible.
That little word- API that you have used there means translating the entire set of system-calls of an operating system to another. Calls that go into creating a socket connection or a directory to file locking etc, EVERYTHING changes. You've discussed just memory here, the GUI has it's own calls, so do drivers and networks.
By the end of 6 years, that little million-line of code that you would've written to achieve all this, when packaged and bundled, will be called; surprise, surprise- a hypervisor.
Related
I'm new to the WSL2 and wondering if it's possible to run the same WSL2 ubuntu instance on both my desktop and laptop.
Now I am able to use wsl --export and wsl --import method to save and load the system to/from my portable hard drive. But these methods takes a long time.
I notice that wsl --import load a file named ext4.vhdx. Is there a way to load straightly from this file?
Update v2.0:
I was able to get a workaround and it works great.
Thanks to Booting from vhdx here, I was able to load straightly from my vhdx file on my portable hard disk. Windows track down its subsystem with regedit, So we can write our own(p.s: make sure to get BasePath right, it starts with "\\\\?", or you will not be able to access the subsystem' filesystem on your host system.):
Windows Registry Editor Version 5.00
[HKEY_USERS\【your SID here】\SOFTWARE\Microsoft\Windows\CurrentVersion\Lxss\{【UUID here】}]
"State"=dword:00000001
"DistributionName"="distribution name"
"Version"=dword:00000002
"BasePath"="vhdx folder path" 【 e.g. "\\\\?\\E:\\S061\\WSL\\ubuntu-20"】
"Flags"=dword:0000000f
"DefaultUid"=dword:000003e8
I suppose the best way to do this would be to store ext4.vhd on a network storage device accessible to both devices.
I have previosly mentioned how to move ext4.vhd. You can check that out here
Basically you need to export from one machine and import it while making sure the vhd file is configured for wsl to access from the network storage
Since this should *officially* not supported expect some performance hits
Another way would be to run WSL on one computer and ssh/remote desktop to it from another device on the network
I'm of the strong belief that sharing the same ext4 vhd between two VM's simultaneously would be a bad idea. See this and this Unix & Linux StackExchange, including the part about ...
note that sharing LVs/partitions on a single disk between the servers at the same time is NOT very safe. You should only access whole disks from any of the servers at one time.
However, as dopewind's answer mentioned, you can access the WSL instance on one computer (probably the desktop) from another (e.g. the laptop). There are several techniques you can use:
If you have Windows 10 Professional or Enterprise on one of the computers, you can enable Remote Desktop, which allows you to access pretty much everything on one computer from another. RDP ("Remote Desktop Protocol") even works from other devices such as an iPad or Android tablet (or even a phone, although that's a bit of a small screen for a "desktop"). That said, there are better, more idiomatic solutions for WSL ...
You could enable SSH server on the Windows 10 computer with the WSL instance (instructions). This may sound counterintuitive to some people, since Linux itself running in the WSL instance also includes an SSH server (by default). But by SSH'ing from (for example) your laptop into your desktop's Windows 10, you can then launch any WSL instance you have installed (if you choose to install more than one) via wsl -d <distroName>. You also avoid a lot of the network unpleasantness in the next option ...
You could, as mentioned above, enable SSH on the WSL instance (usually something like sudo service ssh start) and then ssh directly into it. However, note that WSL2 instances are NAT'd, so there's a whole lot more hackery that you have to do to get access to the network interface. There's a whole huge thread on the WSL Github about it. Personally, I'd recommend the "Windows SSH Server" option mentioned about to start out with, then you can worry about direct SSH access later if you need it.
Side note: Even though I have SSH enabled on my WSL instances, I still use Windows SSH to proxy to them, to avoid these networking issues.
I have the following task:
I installed Linux for Windows in Windows 10 Pro computer;
I installed Ubuntu 18.04 LTS;
I have a separate volume in Windows computer, which doesn't have a drive letter assigned to it;
I need to find a way to mount this Windows volume without letter in WSL Ubuntu.
I know the volume id in case it is required.
Any ideas how to achieve this?
Thx, Vlad.
First of all, my question wasn't completely right, I wrote Linux for Windows but in fact I was talking about "Windows Subsystem for Linux".
The idea is to have 1 disk drive as hardware configured RAID 0 storage which is built with 2x Samsung SSD 1Tb. But for protection of data on RAID 0, I want to use HDD which will sync data with rsync or any cloud service. I selected ownCloud.
Finally, I want to hide the HDD from the system and configure WSL to use it.
Hereby how it works for me:
1) I created a folder here: c:\Users\Public\wsl
2) I mounted the HDD in the folder created above.
3) After the HDD is mounted, I created a subfolder for my favorite Linux distribution: c:\Users\Public\wsl\ubuntu
4) I installed Ubuntu 18.04 in this folder as it described here: Installing WSL on Windows 10 without MS Store
5) The point above allows to install ownCloud server on hidden HDD. Now, in order to get it running at system boot, one can create scripts as described here: how to autoload apache2 and mysql in WSL at Windows boot
6) And finally, to get ownCloud Server running at system boot, even before any user login, one needs to do as follows:
*) Open Windows task scheduler;
*) add a task which runs autostart.sh (see how to make this script on a link above) on system boot;
*) use wscript.exe (from windows system32) as the command to run and the vbs script as parameter. Check this link if you need more details;
7) Finally, we need to setup ownCloud client on the computer and connect it with the server by using http://localhost as the server url.
So, as result of this setup, one gets faster disk system based on 2x SSH configured in RAID 0 and to protect data, one uses a local cloud server in virtual machine to get personal content synchronized with standard HDD.
If the system uses actively SSD, the cloud won't get time for syncing data. But as soon as resources are available, system will sync data in background mode into the HDD, which requires more time to write the same data.
This setup allows to use SSD system at full speed as it is required by applications and it does not limit dramatically the performance of SSD subsystem while keep syncing data in slow HDD as computer resources are available and SSD resources are available.
What's the difference between process virtual machine with system virtual machine?
My guess is that process VM is not providing a kind of an operating system for the whole application for that OS, rather providing an environment for some specific application.
And system VM is providing an environment for an OS to be installed just like VirtualBox.
Am I getting it correct?
Another question is the difference between the two different implementation of system VM: hosted vs. stand-alone.
I'm a beginner studying OS, so easy and understandable answer would be greatly appreciated :)
A Process virtual machine, sometimes called an application virtual machine, runs as a normal application inside a host OS and supports a single process. It is created when that process is started and destroyed when it exits. Its purpose is to provide a platform-independent programming environment that abstracts away details of the underlying hardware or operating system, and allows a program to execute in the same way on any platform.
A System virtual machine provides a complete system platform which supports the execution of a complete operating system (OS),Just like you said VirtualBox is one example.
A Host virtual machine is the server component of a virtual machine , which provides computing resources in the underlying hardware to support guest virtual machine (guest VM).
The following is from http://airccse.org/journal/jcsit/5113ijcsit11.pdf :
System Virtual Machines
A System Virtual Machine gives a complete virtual hardware platform with support for execution
of a complete operating system (OS).
The advantage of using System VM are:
Multiple Operating System environments can run in parallel on the same piece of
hardware in strong isolation from each other.
The VM can provide an instruction set architecture (ISA) that is slightly different from
that of the real machine
The main draw backs are:
Since the VM indirectly accesses the same hardware the efficiency is compromised.
Multiply VMs running in parallel on the same physical machine may result in varied
performance depending on the workload imposed on the system. Implementing proper
isolation techniques may address this drawback.
Lets say I am running Windows 7 with two major processes I will call V and P.
V is a virtual machine running another instance of Windows 7, while P is the process that I want information about and both are on the 'top-level' operating system.
Can a process, C, which is being run by the Windows 7 inside V, get information about processes such as P from within V? In other words, can a process being run inside a virtual machine get any information about processes being run by the operating system which is also maintaining the virtual machine process? I feel like it would rely on the ability of the virtual machine process, if it is not programmed to specifically retrieve such information then it will not be possible.
I have read another topic about the difficulty of even detecting whether a process is being run by a virtual machine or not. Some feel it is not reliable or possible. I am not sure that there is a standard way to find this out yet, I believe the post was roughly 4 or 5 years ago.
So can this be done by process C, or will there need to be more standard routines to accomplish this task?
I don't believe it's possible for an operating system running under a virtual machine manager (e.g. (VMWare et al) to directly access information relating to the host operating system because by default most virtual machine managers attempt to fully isolate the host and guest systems.
That being said most virtual machine managers have mechanisms which allow the virtual machine to share data and communicate with the host system. By using these mechanisms it is possible for the host operating system to convey information about itself to the guest.
Option 1: A shared file
With shared networking between the host and the guest it would be possible to have the host system write the information to a file in the shared location and have the guest open and parse this file using CreateFile and a UNC path e.g. \\host\sharename\file.txt
Option 2: Data transfer via a socket or named pipe
Shared networking between the host and the guest would allow you to use the Windows Sockets or Named Pipe APIs to create TCP or UDP sockets, or a named pipe through which data can be exchanged.
This approach would involve a server application running on the host application, which writes the process information you're after to the socket or pipe, where it can be read by the guest system which runs a client process.
Option 3: Remote Windows Management Instrumentation (WMI) Query
WMI provides a standard means of getting information and interacting with many aspects of the windows operating system including information about processes.
This is probably the most complex option because by default WMI does not accept queries from remote hosts (ie. your VM), so the host machine would need to be configured to allow remote WMI queries.
Once configured WMI is easily usable via the WMI command line client (wmic.exe) so you could invoke it with a query like this:
In this example:
%HOST_NAME% Is the name of the system hosting your Windows 7 VM
%TARGET_PROCESS% is the process name of the process you want
information about
wmi \node:%HOST_NAME% process where name='%TargetProcess%' get executablepath
This particular query gets the executable path of %TargetProcess% but there are many more properties available as per the documentation for the Win32_Process WMI Class documentation1.
Option 4: Shared clipboard
Some virtual machine managers allow the guest system to access the host's clipboard so information can be exchanged between applications running on the guest and host.
I appreciate it's probably the least conventional option but you could conceivably use the Windows Clipboard API to write the process info to the host's clipboard, and then read the information into a process on the guest system.
1NB:Although the Win32_Process class documentation lists properties in title case (ExecutablePath) I found they only worked properly in a wmic query when written in all lower case (executablepath)
What I would like to do is create a clean virtual machine image as the output of a build of an application.
So a new virtual machine would be created (from a template is fine, with the OS installed, and some base software installed) --- a new web site would be created in IIS, and the web app build output copied to a location on the virtual machine hard disk, and IIS configured correctly, the VM would start up and run.
I know there are MSBuild tasks to script all the administrative actions in IIS, but how do you script all the actions with Virtual machines? Specifically, creating a new virtual machine from a template, naming it uniquely, starting it, configuring it, etc...
Specifically I was wondering if anyone has successfully implemented any VM scripting as part of a build process.
Update: I assume with Hyper-V, there is a different set of libraries/APIs to script virtual machines, anyone played around with this? And anyone with real practical experience of doing something like this?
Checkout Powershell Management library for Hyper-V on CodePlex. Some features:
Finding a VM
Connecting to a VM
Discovering and manipulating Machine states
Backing up, exporting and snapshotting VMs
Adding and removing VMs, configuring motherboard settings.
Manipulating Disk controllers, drives and disk images
Manipluating Network Interface Cards
Working with VHD files
You can actually script a fair number of tasks in MS Virtual Server:
http://www.microsoft.com/technet/scriptcenter/scripts/vs/default.mspx?mfr=true
http://msdn.microsoft.com/en-us/library/aa368876(VS.85).aspx
Also Virtual PC guy has got a ton of stuff on his blog about scripting Virtual Server/PC and now Hyper-V here:
http://blogs.msdn.com/virtual_pc_guy/default.aspx
VMware has similar capabilities:
http://www.vmware.com/support/developer/scripting-API/