what is different between the following type i get qemu-kvm ? boths are use centos 6.4.
yum install qemu-kvm ,then show the version:
[root#centos6 qemu-kvm]# /usr/local/bin/qemu-system-x86_64 --version
QEMU emulator version 1.2.50 (qemu-kvm-devel), Copyright (c) 2003-2008 Fabrice Bellard
get the source code and build it by gcc.
[root#centos6 qemu-kvm]# /usr/libexec/qemu-kvm --version
QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2), Copyright (c) 2003-2008 Fabrice Bellard
Qemu uses 2 kinds of cpu virtualization, TCG (tiny code generator) and KVM. TCG emulates all instruction of guest code with plain c code, it translates guest code to host code in real-time. While KVM lets the host directly runs guest code, KVM requires the guest and the host to have the same instruction set (basically, the same cpu), not every cpu can do this, for intel cpus, it requires VMX feature. Which I assume you have understood these.
Qemu-kvm is obsolete, KVM comes with QEMU now if you download the latest code, you just have to compile it with "--enable-kvm" option. Your QEMU source code is very old, the latest version of QEMU is AFAIK, 1.7.
Your yum source provide 1.2.50 version of qemu. Try "yum install qemu", and try running with -enable-kvm if you don't want to build from source code (I haven't tried though)..
Qemu is Hypervisor.
KVM isn't. It is an accelerator(linux module which does the code translation fast) and used with Qemu, because Qemu when used with TCG is slow.
Related
I have installed intel compiler on my Ubuntu 18.04 machine through the following link: https://www.intel.com/content/www/us/en/developer/articles/tool/oneapi-standalone-components.html#dpcpp-cpp
I specifically installed Intel® DPC++/C++ Compiler for Linux.
I am trying to run some benchmarks and they require to source the path <icc_installdir>/bin/compilervars.sh but I can not find this file.
The installation says that Intel compiler was installed in /opt/intel/oneapi but I looked up this directory and there is no bin folder or compilervars.sh. Does anyone know how can I install this file?
Could you please try using the below command to initialize/source the Intel® DPC++/C++ Compiler for Linux?
source /opt/intel/oneapi/compiler/latest/env/vars.sh
And also, to confirm whether it is initialized you can check the version of DPCPP compiler by using the below command.
dpcpp --version
For more information, please find the below link:
https://www.intel.com/content/www/us/en/develop/documentation/oneapi-programming-guide/top/oneapi-development-environment-setup/use-the-setvars-script-with-linux-or-macos.html
Note: This problem, which I have already solved, is a very different problem from every other similar question on Stack Overflow. I have posted this question and answer in the hopes that it will help someone else experiencing the same issue (or so that, when I have this problem again in 3 years, I'll find this answer).
I am running VirtualBox 6.1.26 on macOS Catalina 10.15.7. I am emulating centOS 7:
$ uname -r
3.10.0-1160.36.2.el7.x86_64
I "inserted" the VirtualBox Guest Additions CD and followed the auto-run prompts to install the Guest Additions. Part way through, it aborted, saying:
This system is currently not set up to build kernel modules.
Please install the gcc make perl packages from your distribution.
Note that I have gcc, make, perl, kernel-devel, and kernel-headers all installed. It also prompted me to check the file /var/log/vboxadd-setup.log for more details. The contents of that log were interesting:
Building the main Guest Additions 6.1.26 module for kernel 3.10.0-1160.36.2.el7.x86_64.
Error building the module. Build output follows.
make V=1 CONFIG_MODULE_SIG= CONFIG_MODULE_SIG_ALL= -C /lib/modules/3.10.0-1160.36.2.el7.x86_64/build M=/tmp/vbox.0 SRCROOT=/tmp/vbox.0 -j4 modules
arch/x86/Makefile:96: stack-protector enabled but compiler support broken
arch/x86/Makefile:166: *** CONFIG_RETPOLINE=y, but not supported by the compiler. Compiler update recommended.. Stop.
make: *** [vboxguest] Error 2
modprobe vboxguest failed
Extensive searching for these errors yields multiple forum posts and Stack Overflow questions whose replies and accepted answers reveal either that I'm missing one of those installed packages (I'm not) or that my GCC version is less than 7.3 (when support for CONFIG_RETPOLINE=y was added). However:
$ gcc --version
gcc (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
This is > 7.3, so it does support this feature. I should note that I installed GCC using the Yum devtoolset packages in order to use this newer compiler:
$ sudo yum list installed|grep devtoolset
...
devtoolset-8-gcc.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
devtoolset-8-gcc-c++.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
devtoolset-8-gcc-gdb-plugin.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
...
devtoolset-8-make.x86_64 1:4.2.1-4.el7 #centos-sclo-rh
...
And I do not have any other GCC versions installed:
$ sudo yum list installed|grep gcc
devtoolset-8-gcc.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
devtoolset-8-gcc-c++.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
devtoolset-8-gcc-gdb-plugin.x86_64 8.3.1-3.2-el7 #centos-sclo-rh
libgcc.x86_64 4.8.5-44.el7 #anaconda
And I have this in ~/.bashrc to enable devtoolset upon login:
...
source scl_source enable devtoolset-8
...
What am I doing wrong?
It turned out the problem wasn't that I was using the wrong GCC version (not possible) or that I was missing any installed packages (I wasn't). Instead, it was a consequence of how the VirtualBox Guest Additions "auto-run" works. Something about the way it runs results in a "fresh" environment without devtoolset-8 properly sourced. As a result, it cannot find the installed GCC 8.3.
The solution was simple: When the auto-run prompt appeared, I dismissed it and did not run auto-run. Instead, I opened a fresh Terminal window and changed directories to /run/media/[username]/VBox_GAs_6.1.26 (YMMV on the exact location of the mounted disk), then ran this command:
$ sudo ./VBoxLinuxAdditions.run
That command completed successfully, the kernel module compiled, the Guest Additions installed, and they are working properly now.
I recently compiled a perl script using "pp" (Perl Packager) on an x86 linux box running Manjaro. I had someone test it on their x86 Debian 10 box, but it wouldn't run.
He said that since Libperl.so has a dependence on glibc v2.29. Since his OS release only allows up to a v2.28, that it's preventing it from executing.
Is there a way for me to compile my script with my version of the libraries so it will run on any x86 linux machine?
I ran the following command to compile my code:
pp -o oag1025 oag1025.pl
I tried using some of the options outlined here, but I couldn't get anywhere:
http://perl.mines-albi.fr/perl5.8.5/site_perl/5.8.5/pp.html
Does anyone know if it is possible to install lustre client software on a linux machine that has kernel 4+? From what I have experimented so far, all the working examples are on kernel 3.10. And if I try to install kmod-luster-client on 4+ machine, it fails with:
rpm -ivh kmod-lustre-client-2.10.5-1.el7.x86_64.rpm
error: Failed dependencies:
kernel < 3.10.0-863 is needed by kmod-lustre-client-2.10.5-1.el7.x86_64
kernel(PDE_DATA) = 0x44f0d59d is needed by kmod-lustre-client-2.10.5-1.el7.x86_64
According to lustre/ChangeLog in the b2_10 branch, it works with kernels at least 4.4.133-94.33 (SLES12SP3) and 4.4.0-131 (Ubuntu 16.04).
If you are using a newer kernel, you also need to use a newer version of Lustre. The lustre/ChangeLog on the tip of master (almost 2.12 release) reports support for kernels 4.15.0-32 (Ubuntu 18.04).
It looks like you are trying to install a binary kernel module RPM built for the RHEL7 kernel on a non-RHEL kernel. That is never going to work. You need to either get the right RPMs/Debs for your kernel from https://lustre.org/download/ or download the source and rebuild it for your kernel.
The 2.10.x kernels are currently the LTS maintained releases (bugfixes backported to that release), while 2.11.0 is a feature release that does not have bugfixes backported.
I have a HostGator VPS server, and want to be able to run pdftotext, part of xpdf (http://www.foolabs.com/xpdf/download.html).
After testing this out on my Mac, it worked fine, so I went to installing it on my VPS server.
I followed the installation instructions and it all isntalled flawlessly:
Copy the executables (xpdf, pdftotext, etc.) to to /usr/local/bin.
Copy the man pages (*.1 and *.5) to /usr/local/man/man1 and /usr/local/man/man5.
Copy the sample-xpdfrc file to /usr/local/etc/xpdfrc
Then I tested it out:
root#*** [~]# pdftotext
pdftotext: /lib64/libc.so.6: version `GLIBC_2.11' not found (required by pdftotext)
So as you can see, it couldn't find /lib64/libc.so.6. /lib64/libc.so.6 is there, however, as shown by this:
root#*** [~]# /lib64/libc.so.6
GNU C Library stable release version 2.5, by Roland McGrath et al.
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.1.2 20080704 (Red Hat 4.1.2-52).
Compiled on a Linux 2.6.9 system on 2012-03-19.
Available extensions:
The C stubs add-on version 2.1.2.
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
GNU libio by Per Bothner
NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
RT using linux kernel aio
Thread-local storage support included.
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
I then contacted HostGator, where they told me that it will not work on my server, as it can't find /lib64/libc.so.6, and is therefor not available on Centos 6 64bit.
If this is indeed true, are there any alternatives to pdftotext that do a simple and fast conversion that would work on this server? Is it possible that the pdftotext can be complied for a different version, or that I installed it incorrectly with permissions?
Neither of these commands will work:
yum install xpdf
yum install poppler-utils
xpdf will install poppler-utils anyway and this will result in this pdftotext
pdftotext version 0.26.5
Copyright 2005-2014 The Poppler Developers - http://poppler.freedesktop.org
Copyright 1996-2011 Glyph & Cog, LLC
This is not the version you want. You want this one:
pdftotext version 4.03 [www.xpdfreader.com]
Copyright 1996-2021 Glyph & Cog, LLC
This will require going to www.xpdfreader.com and then clicking on "Download". Use the latest versions from this page to set up the newer pdftotext command.
I actually compiled the sources myself:
cd /tmp
wget https://dl.xpdfreader.com/xpdf-4.03.tar.gz
tar -xf xpdf-4.03.tar.gz
cd xpdf-4.03
mkdir build
cmake -DCMAKE_BUILD_TYPE=Release
If successful you should see:
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/xpdf-4.03
Then just type:
make
It should end with:
[100%] Built target pdftotext
Then type
make install
Now when you type pdftotext you should see:
pdftotext version 4.03 [www.xpdfreader.com]
Copyright 1996-2021 Glyph & Cog, LLC
Note: I wrote all my code for pdftotext version 4.03. Took me a while to realise 4.03 and 0.26 produce vastly different results.