Xen: VM failed to boot

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Question: Hello, I am using Xen on Centos 7 and it was working fine from last 3 years. After I reboot the VM I am getting below error: “dracut-initqueue[270]: Warning: dracut-initqueue timeout – starting timeout scripts” “[ 195.426203] dracut-initqueue[270]: Warning: Could not boot. [ 195.435712] dracut-initqueue[270]: Warning: /dev/centos_static/root does not exist [ 195.436499] dracut-initqueue[270]: Warning:
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How to mirror a website using wget on Linux?

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How to mirror a website using wget on Linux? If the command can filter only specific file extensions, such as pdf and docx, it will be much better too. To download all PDF files from https://example.org/path/ as an example, you may use this command: wget –mirror \ –convert-links –no-parent –quiet \ –adjust-extension -A pdf \
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How to enable user themes in Ubuntu 18.04?

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The way for Ubuntu 17 to installing the gnome-shell-extensions package does not work any more for Ubuntu 18.04. How to enable user themes in Ubuntu 18.04? The updated gnome-shell-extensions package actually adds the User Theme extension back. You can use that. First, install the package sudo apt install gnome-shell-extensions Second, log out and login again
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How to get date and time using date command from another timezone in Linux?

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date command on Linux gets the date and time in the system timezone. But how to get date and time using date command from another timezone in Linux? You can make date print the time of another timezone by setting the TZ environment variable. For example, export TZ=Hongkong; date Sat Dec 1 09:39:13 HKT 2018
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How to change the logo shown during booting in Ubuntu?

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How to change the logo shown during booting in Ubuntu? I originally installed Ubuntu MATE 18.04. But I am using GNOME 3 now by replacing the DE. But the log shown during booting is still Ubuntu MATE’s. How to change it to another one? It is plymouth the application that manages the “splash” screen during
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GNOME 3 "Natural scrolling" mouse option does not work

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In GNOME 3 “Settings” -> “Devices” -> “Mouse & Touchpad”, after setting “Natural scrolling” to On, the scrolling is still as the same before (non-natural). How to fix this? This is likely related to the X11 driver. Remove the xorg-x11-drv-synaptics driver if it is installed. And install the xorg-x11-drv-libinput driver if it is not installed.
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How to install GNOME 3 in Ubuntu MATE 18.04?

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How to install the GNOME 3 (gnome-shell) desktop environment in Ubuntu MATE 18.04? To install gnome3 to Ubuntu, install these packages sudo apt install gnome-session gdm3 ubuntu-desktop During installation, the installation tools will let you choose the default display manager. You may choose gdm3. Then reboot you Ubuntu Linux and gdm3 will be shown. Click
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Installing Zlib Library in Ubuntu Linux

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On Ubuntu (18.04 and 20.04), installing zlib reported unable to locate package zlib: $ sudo apt install zlib Reading package lists… Done Building dependency tree Reading state information… Done E: Unable to locate package zlib How to install zlib in Ubuntu? Install zlib in Ubuntu from Ubuntu package repo In Ubuntu, the zlib package is
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How to add Chinese input method to Unbuntu 18.04?

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How to add Chinese input method, such as Pinyin, to Unbuntu 18.04? To input Chinese, first install an input method framework. Here, we use fcitx. Then you need to input the Pinyin input method. You may use fcitx-sunpinyin. Put them all together $ sudo apt-get install fcitx fcitx-sunpinyin After that, set the default input method
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File system Inode flags: difference between FS_IOC_GETFLAGS and FS_IOC_FSGETXATT

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What is the difference between FS_IOC_GETFLAGS and FS_IOC_FSGETXATTR ioctl commands? What flags do both return? The comment in fs.h is clear enough to explain itself. In short, FS_IOC_GETFLAGS was for ext2/ext3 only, and FS_IOC_FSGETXATTR is a generic FS level interface. Full comment as follows for your reference (source): /* * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
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How to call a function by its name as a string in PHP?

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In PHP, how to call a function by its name as a string? The name strings may be known only at run time. If the string containing the function name is $func, you may call the function like $func() or call_user_func($func) using call_user_func(). The call_user_func() function supports more usage patterns, like call_user_func( array($obj,$func), $params )
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