Linux boots failed with “sulogin: can not open password database” while the /etc/passwd and /etc/shadow files look fine. How to fix this? The OS is Fedora 22. You may try this trick Step 1: boot Linux with rw init=/bin/bash following this tutorial. Step 2: after Linux booted, disable SELinux following this tutorial. Reboot. If it
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Tag: OS
How to keep master thesis safety and availability on Windows
Posted onWhen you write your master thesis (in Chinese) on windows, you may have following worries. a, Be afraid your master thesis is lost (or can not be accessed) when hard disk/udisk is broken (or something other viruses). b, Keep master thesis availability (7×24) and safety. c, Do not want anyone else to access it before
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How to get file size in Python?
Posted onHow to get a file’s size in Python from the full path of a file? You can use this piece of Python code: os.path.getsize(file_path) It returns the size in bytes. It raises os.error if the file does not exist or is inaccessible. Manual of os.path.getsize(): https://docs.python.org/2/library/os.path.html#os.path.getsize
How to iterate all files and directories under a directory in Python?
Posted onHow to iterate all files and directories under a directory in Python? For example, I would like to iterate each file and directory under /mnt/data/ /mnt/data/ |– file.txt `– great That is: /mnt/data/files.txt /mnt/data/great You can use the os.walk to do this: root, dirs, files = os.walk(path).next() root will be the path.dirs will contain the
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How to get the file extension from a filename in Python?
Posted onHow to get the file extension from a filename in Python? For example, I would like to get “.txt” from “file.txt”. The Python code: >>> name, ext = os.path.splitext(‘file.txt’) >>> name ‘file’ >>> ext ‘.txt’ Manual of os.path.splitext: https://docs.python.org/2/library/os.path.html#os.path.splitext
How to configure Linux to use the scanner in an HP all-in-one printer?
Posted onHow to configure Linux to use the scanner (not only the printer) in an HP all-in-one printer? The OS is Fedora 22 and the connection between the HP all-in-one printer and the PC is through wireless. The printer is working well. You can check this post for configuring the printer and scanner of HP All-In-One
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Skype crashes because it cannot read data from “C:Documents and SettingsAdministratorLocal SettingsTemp”
Posted onOn my laptop, I install windows xp because it is user-friendly for me. However, Skype cannot be open because “The system is not unavailable”. At last, I find the “Skype” directory under “C:Documents and SettingsAdministratorLocal SettingsTemp” cannot be accessed. “C:Documents and SettingsAdministratorLocal SettingsTemp” is like temporary directory for specific user under Linux OS. Actually, for
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VirtualBox report “Kernel driver not installed” on Fedora 21
Posted onVitualBox is installed on Fedora 21 by # yum install VirtualBox The following packages are installed kmod-VirtualBox-3.18.7-200.fc21.x86_64-4.3.20-4.fc21.4.x86_64 VirtualBox-4.3.20-3.fc21.x86_64 There is the kernel modules package installed. However, when running virtualbox (after reboot), it reports: [zma@laptop:~]$ virtualbox WARNING: The vboxdrv kernel module is not loaded. Either there is no module available for the current kernel (3.18.7-200.fc21.x86_64) or
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Any good Web browser in command line in Linux?
Posted onWhat suggested web browser in command line? This will be very useful for browsing the Internet from a command line via SSH. You may use Lynx, a fully-featured World Wide Web (WWW) client for users running cursor-addressable, character-cell display devices, in Linux. Homepage: http://lynx.isc.org/ Lynx is a fully-featured World Wide Web (WWW) client for users
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How to dynamically attach a disk to running DomU in Xen?
Posted onI want to attach a disk to a DomU. The Xen DomU is running and should not be rebooted. Hence, changing its configuration file is not an option. How to dynamically attach a disk to running DomU in Xen? To attach phy:vg_xen/vm-228-large to vm-228 as xvdb, run this on Dom0: # xl block-attach vm-228 phy:vg_xen/vm-228-large
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How to config network in host (wireless network) for QEMU guest os
Posted onThe host os is connected into network by wireless one so how to let its guest os connect network. Take [1] as a reference. I run it successfully with following steps. 1, create /etc/qemu-ifup script and chmod it. 2, start a qemu guest os with command sudo ./qemu/qemu-system-x86_64 -enable-kvm -m 1024 -drive file=marss_dram.qcow2 -vnc 127.0.0.1:0
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Cannot connect QEMU guest os with vncviewer
Posted onThe question is as follows. harry@debian:~/workshop1/qemu_test/version1/test$ qemu-system-x86_64 -hda qcow2.img -cdrom domU-x86_64-FS.img -boot d -m 1024 VNC server running on `::1:5900′ harry@debian:~/workshop1/qemu_test/version1/test$ vncviewer 127.0.0.1:1 vncviewer: ConnectToTcpAddr: connect: Connection refused Unable to connect to VNC server Solution (add -vnc parameter for qemu-system-x86_64): harry@debian:~/workshop1/qemu_test/version1/test$ qemu-system-x86_64 -hda qcow2.img -cdrom domU-x86_64-FS.img -boot d -m 1024 -vnc 127.0.0.1:2 harry@debian:~/workshop1/qemu_test/version1/test$ vncviewer 127.0.0.1:2
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How to un-trust a computer that I have trusted with iOS 7 device?
Posted onHow to un-trust a computer that I have trusted with iOS 7 device, such as iPhone? You can delete the Lockdown folder to reset the trust/un-trust status of iPhones. Apple provides tutorials for Max OS X and Windows at: http://support.apple.com/kb/TS5335 (archived) . If you are using Linux, the Lockdown folder is: /var/lib/lockdown Answered by Lucy.
Enlarging Linux UDP buffer size
Posted onOne of the most common causes of UDP data gram lost on Linux is an undersized receive buffer on the Linux socket. How to enlarge Linux UDP buffer size? On Linux, you can change the UDP buffer size (e.g. to 26214400) by (as root): sysctl -w net.core.rmem_max=26214400 The default buffer size on Linux is 131071.
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How to fetch a webpage as a mobile browser with curl on Linux?
Posted onOn Linux, how to download a webpage as a mobile browser? You can change the agent of curl to be a mobile browser’s and the remote webserver may be consider the request from a mobile browser: curl -A “Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_3 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) CriOS/28.0.1500.12 Mobile/10B329 Safari/8536.25”
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How to change default OS for windows dual boot manager in Windows 7?
Posted onHow to change default OS for windows dual boot manager in Windows 7? The c:/boot/ in older Windows does not exist anymore. Open the Control Panel and click on the System icon. In the left pane, click on the Advanced system settings link. Under the Advanced tab, click on the Settings button under Startup and
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Xen HVM DomU configuration file
Posted onAn example of Xen HVM DomU configuration file. An example for install the OS from an ISO: name=”10.0.1.235″ vcpus=2 memory=2048 shadow_memory=8 disk=[‘file:/lhome/xen/vm-10.0.1.235/vmdisk0,xvda,w’, ‘file:/lhome/Linux-x86_64-DVD.iso,xvdc:cdrom,r’] vif=[‘bridge=xenbr0′] kernel=’/usr/lib/xen/boot/hvmloader’ builder=’hvm’ device_model=’/usr/lib64/xen/bin/qemu-dm’ extra=” vnc=1 vnclisten=”0.0.0.0″ vncpasswd=’1234567′ # vncdisplay=1 vncconsole=1 on_reboot=’restart’ on_crash=’restart’ An example for run the VM after installation: name=”10.0.1.235″ vcpus=2 memory=2048 shadow_memory=8 disk=[‘file:/lhome/xen/vm-10.0.1.235/vmdisk0,xvda,w’] vif=[‘bridge=xenbr0′] kernel=’/usr/lib/xen/boot/hvmloader’ builder=’hvm’ device_model=’/usr/lib64/xen/bin/qemu-dm’ extra=” vnc=1
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HTML form generation from the database and store value into the database
Posted onI have a “t_form” table and a “t_attribute” table. It looks a little bit like below. Form table form_id | form_name | description ———————————– 1 | Laptop | Possible attributes are Model, Screen Size, OS, Cd Player 2 | Mobile | Possible attributes are Model, OS 3 | Tablet | Possible attributes are Model, Screen
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Installing Dropbox on Linux
Posted onHow to install Dropbox on Linux ? Just follow Dropbox’s instruction here: https://www.dropbox.com/install?os=lnx A quick command for 64-bit Linux: $ cd ~ && wget -O – “https://www.dropbox.com/download?plat=lnx.x86_64” | tar xzf – Use the dropx CLI:Â http://www.dropboxwiki.com/Using_Dropbox_CLI Download dropbox.py: $ wget -O ~/bin/dropbox.py “https://www.dropbox.com/download?dl=packages/dropbox.py” Set the permissions: $ chmod +x ~/bin/dropbox.py Start Dropbox: $ dropbox.py start Status:
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NET Core 2.1 Release: Feature To Expect in 2018
Posted onWhat surprises are awaiting the tech world with .NET Core 2.1 Release in 2018? Technology is one of the most dynamic spheres these days. Every single year you will find a new version of an existing software and .NET Core is not an exception. The intentions of these upgradation is to make online activities seamless,
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