When use gitbook to generate ebook, Calibre reports this: RuntimeError: X server required. If you are running on a headless machine, use xvfb After xvfb is installed, it does not work either. How to make gitbook/Calibre work on a headless server? You need to wrap the command ebook-convert with xvfb-run. However, in gitbook (lib/generate/ebook/index.js), ebook-convert
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Tag: Command line
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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How to change number of replications of certain files in HDFS?
Posted onThe HDFS has a configuration in hdfs-site.xml to set the global replication number of blocks with the “dfs.replication” property. However, there are some “hot” files that are access by many nodes. How to increase the number of blocks for these certain files in HDFS? You can the replication number of certain file to 10: hdfs
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How to get logs of a specific time range on Linux?
Posted onThe logs I am processing is Hadoop log (log4j). It is in format like: 2014-09-20 21:55:11,855 INFO org.apache.hadoop.nfs.nfs3.IdUserGroup: Updated user map size: 36 2014-09-20 21:55:11,863 INFO org.apache.hadoop.nfs.nfs3.IdUserGroup: Updated group map size: 55 2014-09-20 22:10:11,907 INFO org.apache.hadoop.nfs.nfs3.IdUserGroup: Update cache now 2014-09-20 22:10:11,907 INFO org.apache.hadoop.nfs.nfs3.IdUserGroup: Not doing static UID/GID mapping because ‘/etc/nfs.map’ does not exist. Now, I
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How to read email in Maildir on Linux?
Posted onHow to read email in Maildir on Linux? You can use mutt by: mutt -f /path/to/mail/dir/
Making Hadoop Java process heap larger?
Posted onIn Hadoop 2.5.0, I use ‘ps -aux’ and find the Java process has options: -Xmx1000m However, my nodes have 32GB memory. How to make Hadoop Java process heap larger? In yarn-env.sh, you can find: # For setting YARN specific HEAP sizes please use this # Parameter and set appropriately # YARN_HEAPSIZE=1000 In hadoop-env.sh, you can
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How to capture camera photo/video using MPlayer on Linux?
Posted onHow to capture camera photo/video using MPlayer on Linux? You can watch the video from the camera by MPlayer: # mplayer tv:// Note that you need the root privilege to play the tv://. You can use mplayer to capture photos by: # mplayer -vo png -frames 3 tv:// If will store files 0000000{1..3}.png in the
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How to unlock a locked SSH terminal accidentally by ctrl-s on Linux?
Posted onI find I sometimes lock the SSH terminal accidentally by ctrl-s on Linux. How to unlock/unfreeze it? Ctrl-s: lock the SSH terminal. Ctrl-q: unlock the SSH terminal.
How to find and change a user’s UID on Linux?
Posted onHow to find and change a user’s UID on Linux? Find the UID of a user: id -u $USER_NAME Change a user’s UID: # usermod -u $NEW_UID $USER_NAME
How to back up emails from the email server?
Posted onofflineimap actually does “synchronization”—if an email is deleted from the server, the email will be deleted from the local Maildir (http://offlineimap.org). This is good for mail sync. However, for backing up emails,one would like to keep the email even if it is deleted from the server. How to achieve this? You may use `getmail` which
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How to backup iPhone on Linux?
Posted onHow to backup iPhone on Linux? Not using iTunes or Windows. You can backup iPhone using libimobiledevice. By the time I replied here, it supports up to iOS 7. Please check this post for a tutorial. Actually, the methods introduced can be used on Linux systems with the libimobiledevice installed. Backup iPhone: idevicebackup2 backup ~/iPhoneBackups/
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How to find the history of updated packages by apt-get or aptitude?
Posted onHow to find the history of updated packages by apt-get or aptitude? The history is in log files of dpkg and apt: /var/log/dpkg.log /var/log/apt/history.log /var/log/aptitude To check the recently installed packages: cat /var/log/dpkg.log | grep ” install ” To list history of recently installed packages by apt-get: cat /var/log/apt/history.log | grep ” install ” To
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Manage Linux console screen by commands?
Posted onHow to manage Linux console screen by commands? When the screen will be blanked? Put the screen into powerdown mode or power off the screen? 2 tools are useful for managing the console screen on Linux: setterm – set terminal attributes.vbetool – run real-mode video BIOS code to alter hardware state. When the screen will
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How to monitor temperatures of laptop on Linux
Posted onHow to monitor temperatures of laptop on Linux? This works on Linux Mint: sudo aptitude install lm-sensors hddtemp For lm-sensors, first detect the sensors by: sudo sensors-detect To detect the temperature in the system: sudo sensors To detect the HDD (e.g. sda) temperature: sudo hddtemp /dev/sda An example of the output: [zma@mini:~]$ sudo sensors acpitz-virtual-0
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How to boot Linux Mint to the console by default?
Posted onHow to boot Linux Mint to the console by default? (that is, the run level 3). 2 methods introduced here to boot Linux Mint to console/command line. Method 1 (may only work for earlier releases; check method 2 below): set kernel option. Edit /etc/default/grub and add text to GRUB_CMDLINE_LINUX_DEFAULT: GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash text” Then, re-generate grub
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How to rotate a .mov video from iPhone by 90 degree on Linux?
Posted onThe video files copied from iPhone is rotated by 90 degree when they are played on Linux. How to rotate a .mov video from iPhone by 90 degree on Linux? Specifically: 1) Play the video by rotating 90 degree. 2) Edit the video by rotating 90 degree and save it. You may check Rotating Video
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How to turn a BIOS-based Linux Mint 17 installation to UEFI booting?
Posted onI installed Linux Mint 17 in the traditional BIOS mode. However, Windows 8.1 on my computer can only boot in the UEFI mode. I do not want to reinstall the Windows or erase it. How to turn a BIOS-based Linux Mint 17 installation to UEFI booting? You may refer https://help.ubuntu.com/community/UEFIBooting for some information.
Finding Which Package Provides a File in Ubuntu Linux and Linux Mint
Posted onHow to find which package provides a file in Debian based releases, such as Linux Mint, Ubuntu? You can use `dpkg`: $ dpkg -S /path/to/the/file -S or –search is the option to make dpkg do a “search”: -S, –search filename-search-pattern… Search for a filename from installed packages. To search which package provides a command file
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How to set the number of mappers and reducers of Hadoop in command line?
Posted onHow to set the number of mappers and reducers of Hadoop in command line? Number of mappers and reducers can be set like (5 mappers, 2 reducers): -D mapred.map.tasks=5 -D mapred.reduce.tasks=2 in the command line. In the code, one can configure JobConf variables. job.setNumMapTasks(5); // 5 mappers job.setNumReduceTasks(2); // 2 reducers Note that on Hadoop
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Replacing with a string with newline in Emacs?
Posted onHow to replacing a string with another string with newline in Emacs? For example, to replace: good editor with good editor: Emacs What you need is actually to input a newline in Emacs: C-q C-j C-q is for quoted-insert, and C-j is a newline (0xa).