Hadoop name node fails to load in VirtualBox after sometime - apache

I've configured and am running Hadoop v2.7.2 along with OpenJDK v7 u191. Once the configuration is done, all the process namely name node, data node, secondary name node, etc. runs perfectly (Checked with jps).
I'm running Ubuntu 14.0.4 LTS in Oracle VirtualBox (Currently VirtualBox is running in Windows10).
Once the system is halted (or shut down) for some time, then after restarting Hadoop, name node fails to start. All other processes other than name node is working fine, yet the name node is not.
I've tried reinstalling and reconfiguring the whole thing from the scratch, yet the problem is like it was. Also, I would like to add that there was no error when Hadoop was installed along with other software. I have also tried to reformat HDFS, but that doesn't work either.
I'm new to Big Data and Hadoop, so it would be very helpful if anyone could tell me what exactly is wrong and how to solve it step-by-step.
One more thing, someone previously advised me to configure SSH server to run hadoop properly, so I'd configured SSH server along with.
This is what Happens, when I restart my Ubuntu after sometimes
Image: Ubuntu

Related

WSL2 stopped working with error The system cannot find the path specified

WSL2 stopped working suddenly. If I do a new installation of linux distros. Then it throws the following error, when I click launch button for the linux distro from play store:
Installing, this may take a few minutes...
WslRegisterDistribution failed with error: 0x80070003
Error: 0x80070003 The system cannot find the path specified.
the wsl --help command works properly. All other wsl command hangs or throws error as shown below
like wsl -l command throws this error
The system cannot find the path specified.
I had the same thing happening to me after I moved the directory of my distro.
You have to unregister the distro from WSL;
wslconfig /u Ubuntu-20.04
and then just execute the installed exe and install the whole distro to WSL again.
I had to reinstall the windows to fix the issue. Something got corrupted in the OS. However, before reinstalling the OS as I had lot of work stored in the WSL2, I took the backup of the entire WSL2 image, the big .vhdx file. This file is the Virtual Hard Disk of WSL2 Linux. The files inside cannot be directly explored from Windows at the moment.
If one has not moved the file anywhere else, it is stored here: %LOCALAPPDATA%\Packages\<PackageFamilyName>\LocalState\ext4.vhdx
Before reinstalling the OS, after taking the backup, I wanted to test if this backup runs fine on new install of WSL2. For that, I tested it on another machine, by installing the same Ubuntu WSL2 distro and replacing the .vhdx file created with the backup file. It ran fine.
So, it felt safe to do entire OS reinstall and then reinstalling WSL2 Ubuntu and finally replacing the .vhdx file with the old backup .vhdx file. So, I did loose some time. But, my data and all the applications/programs on WSL2 were intact.
I know this is old but I had the same problem after deleting a driver associated with Hyper V and fixed it by uninstalling the virtual machine platform and Windows Hypervisor along with WSL, rebooted, reinstalled all 3 and then I could install Ubuntu again
This is my first answer on stack overflow and English is not my first language.
So, I will answer this question in images. My solution would not delete the date in any existing installed Linux distribution, at least for me.
Hope you can solve this problem successfully.
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"Enable" Virtualization from your bios settings.
Settings may differ from bios to bios (search for your machine options)

Ubuntu on WSL doesn't launch

I have installed Ubuntu 18.04 for windows subsystem for linux on windows 10, after enabling WSL in Powershell (instructions here: https://learn.microsoft.com/en-us/windows/wsl/install-win10).
I've done this before on a desktop but now I'm doing it on a laptop. I had no issues with the previous installation but this time around ubuntu will not launch. I get the ubuntu console popping up briefly before disappearing.
Also trying to run bash.exe from the command line fails silently (doesn't hang, just exits with no message), which may be related.
I'm struggling to figure this out as I have no idea where any error messages might be logged. Does anyone know how I can investigate further why this is happening?
Setup is a windows 10 Pro, os build 17134.376, everything up to date.
I'm struggling to figure this out as I have no idea where any error messages might be logged. Does anyone know how I can investigate further why this is happening?
Check with wslconfig.exe /l all registered distros, try to deregister the one you have problem with ( e.g. wslconfig.exe /u Ubuntu [^1]) and run the ubuntu.exe in your distro once again. Just a wild guess, it might be also a problem, if you have more than one copy of the linux distribution in you home directory.
[^1]: Warning: deregistering will delete all the associated files!

Openstack recover orphaned instances

I'm using Openstack Havana with one compute node based on kvm and a controller node running in a VM.
After a bad hardware failure I got into a situation where the controller is aware of a subset of the instances (preceding a certain date) and completely lost the newer instances. I suppose we had to restart from an older backup instance of the controller.
All the information about the instances is still available on the compute node (disk, xml) and they even still appear in virsh list --all.
Is there a way to just re-import them into the controller? Maybe by sql or some nova command line?
Thanks.
Ok. We solved the issue the rough way. Converting the disk file produced for OpenStack (OS) instances to VDI (thanks qemu-img) we then run the suitable glance command to import the VDI as an image into OS. From the dashboard we then created an instance on that image and reassigned our floating-ip.
Anyone has counter-indications to this?
Thanks.

boot2docker inside VBox

I would like to use boot2docker for Windows inside a VirtualBox (Windows XP 64-bits, VT-x enabled).
I tried to start the last version of boot2docker (v1.6.2) but the boot2docker start command does not end, both using the Boot2docker shortcut or running directly boot2docker start in Windows terminal.
The "boot2docker init" actually works, but the "boot2docker up" outputs (I waited for one hour, still up):
Waiting for VM and Docker daemon to start..............................................ooooooo
There is no failure, no message, nothing major in Logs from boot2docker-vm and its state is "running".
I tried "boot2docker ssh" in another Terminal but it fails with error "error in run: exit status 255" ("boot2docker ip" fails with "Failed to get VM Host only IP address. Was the VM initialized using boot2docker?").
I guess this issue can be related to the usage of Windows inside a VB by contrast with "native" Windows.
Did someone already successfully use older versions of boot2docker inside a VirtualBox? Or maybe it is not possible...
This happened to me once, and I did a
boot2docker delete
boot2docker init
boot2docker up
and it worked.
It is rather impossible to run boot2docker inside the VirtualBox as boot2docker is based also on VirtualBox and unfortunately such nesting is not supported - here is feature request concerning this (its worth to show your interest there! :).
People are reporting success running nested VirtualBox configuration but they are using 32 bit OS for inner instance and docker supports currently only 64 bit OS.
There are however some unofficial tries to run docker on 32 bit OS but then there is a need of dedicated 32 bit docker images.
It would be interesting if such combination of above have worked for somebody.

NFS unavailable until NFS server restart

I have quite a strange problem with NFS. I have two systems. One is my workstation, Ubuntu 13.04, linux kernel 3.8.0. Here I've got a directory with code I am working on: /home/user/source. The other is a virtual machine running on some remote server. It has Centos 6.3 and mounts the directory at /opt/source. The point is I have got a whole development environment there needed to run my code, but I want to store the code itself on my local machine for easier acces for Eclipse and other development tools.
Unfortunately, when I reboot my local machine, the NFS filesystem is unavailable on the virtual box until I run: /etc/init.d/nfs-kernel-server restart. I cannot figure out why. Here's the only line in /etc/exports on my local machine:
/home/user/source 10.0.19.192(rw,sync,subtree_check)
And here's the line from /etc/fstab on virtual machine, where the NFS is described:
10.10.1.205:/opt/source /opt/WP nfs defaults,nofail 0 0
It looks like your NFS server wasn't started at boot time. I think, even on Ubuntu 13.04, you can still manage this with the "rcconf" program:
sudo apt-get install rcconf dialog
sudo rcconf
Then, check off nfs-kernel-server.
If for some reason this isn't working, try a similar process with the sysv-rc-conf package.