One of HDFS cluster’s hdfs dfsadmin -report reports: Under replicated blocks: 139016 Blocks with corrupt replicas: 9 Missing blocks: 0 The “Under replicated blocks” can be re-replicated automatically after some time. How to handle the missing blocks and blocks with corrupt replicas in HDFS? Understanding these blocks A block is “with corrupt replicas” in HDFS
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Tag: Tutorial
How to make AdSense responsive ads show rectangle ads instead of horizontal ones?
Posted onI noticed that many sites with AdSense responsive ads show large rectangle ads (336px x 280px) or large rectangle text ads (full width x 280px). However, in my own website (640px width content area), it shows most of time horizontal ones. How to make AdSense responsive ads show rectangle ads instead of horizontal ones? At
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How to find a network adapter’s speed in Linux?
Posted onI have a Linux box and it is connected to a network through a network adapter, say gate. How to find what is the current speed (10Mbps, 100Mbps or 1000Mbps) of the adapter? You can find the network adapter speed by the ethtool command: ethtool: query or control network driver and hardware settings For example,
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How to find a wireless network adapter’s speed in Linux?
Posted onHow to find a wireless adapter‘s speed in Linux? ethtool does not show the speed of the wireless adapters. For finding the configured speed of wireless adpaters in Linux, you can use the iwconfig tool. iwconfig: configure a wireless network interface For example, to find the speed of the wireless adapter wlp8s0: # iwconfig wlp8s0
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Printing “powernow-k8 transition frequency failed” after install XEN
Posted onAfter I installed XEN hypervisor, the tty0 (CTRL+ALT+F1) prints “powernow-k8 transition frequency failed” to STDOUT continously, how to solve it? sudo rmmod powernow_k8 From https://lists.debian.org/debian-user/2013/01/msg00754.html How to make the settings persistent (take effect after reboot)? 1, Create script file ‘/etc/init.d/stop_pwoerk8.sh’ as follows. harry2vera@node1:/etc/init.d$ cat stop_pwoerk8.sh #! /bin/sh rmmod powernow_k8 2, Add the full PATH of
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How to disable SSH reverse DNS lookup on Linux?
Posted onHow to disable the reverse DNS lookup by the SSD server on Linux? To turn off reverse DNS lookups of the SSH daemon, log on the server and add UseDNS no to /etc/ssh/sshd_config. And remember to restart the sshd service by service sshd restart or systemctl restart sshd.service or other commands depending on your system.
rtnetlink answers file exists
Posted onWhen you replace dynamic IP to static IP, you may need to restart your netwrok on Debian as follows. $sudo /etc/init.d/networking restart … …. reconfiguring network interfaces…rtnetlink answers file exists … However, error happens here “rtnetlink answers file exists”. How to solve it??? Run following commands could solve this problem # ip addr flush dev
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Vim turns to be slow after enabling some plugins, how to find which leads the problem?
Posted onVim itself is very fast. But it turns to be slow after enabling some plugins. How to find which plugin leads the slowness of Vim? You may use the profiling mechanisms in Vim. Please check a tutorial on profiling Vim. For profiling Vim startup: vim –startuptime profile.log For profiling certain actions in Vim: :profile start
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How to exclude last N columns in Bash on Linux?
Posted onHow to exclude last N columns of a string in bash? The point is that the number of columns in each line is uncertain (but > N). For example, I would like to remove the last 2 columns separated by ‘.’ in the following lines. systemd.3.gz systemd.mount.3.gz systemd.mount.f.3.gz The simple cut command cut -d’.’ -f1
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How to sort all files recursively by modification time in a directory on Linux?
Posted onHow to sort all the files in a directory and subdirectories recursively by modification time on Linux? You can make use of find (GNU find, or plus stat), sort and sed together to achieve recursively sort files by modification time: find . -type f -printf ‘%T@ %pn’ | sort -k 1 -n | sed ‘s/^[^
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How to make WordPress regenerate the thumbnails after I changing the media aspects?
Posted onI recently changes the media aspects. The problem is that the existing thumbnails are not changed to the new aspects. How to make WordPress regenerate the thumbnails after I changing the media aspects? The “Regenerate Thumbnails” works like a charm for me: https://wordpress.org/plugins/regenerate-thumbnails/ . It allows you to regenerate your thumbnails after changing the thumbnail
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How to edit eps file?
Posted onI have made some eps figures for my paper but now I wanna modify them. How to edit them now? You may try inkscape on Linux: https://inkscape.org/en/ It can edit eps files.
How to find which program or process is listening on a certain port in Linux?
Posted onMy program reports that the port is already used. How to find which program or process is listening on a certain port in Linux? You can use netstat to do this. netstat can print network connections. For example, to find which program is listing on port 9999 netstat -pln | grep 9999 You will need
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How to move all the files under Users for a user to another drive on Windows?
Posted onUnfortunately, my C: drive is almost full. Most of the space are used by the user home under C:Users. How can I move the home directory to another drive while not affecting the user’s usage of Windows. On Linux/Unix, moving the directory to another drive/partition and then keeping a softlink is enough. But how to
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How to redirect WordPress search query to Google CSE?
Posted onHow to redirect WordPress search query to Google CSE? You can configure Google CSE to read the query variable (by default, it is q). Then, in your WordPress’s .htaccess file, add these 2 lines RewriteCond %{QUERY_STRING} ^s=(.*)$ RewriteRule ^ https://www.google.com/cse/publicurl?cx=xyz&q=%1 [R,L] Here, “https://www.google.com/cse/publicurl?cx=xyz” is your CSE’s public URL or the webpage that contains the Google
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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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How to limit the network rate used by scp in Linux?
Posted onI am using a shared network and scp to upload files. I do not want to use most of the bandwidth available. How to limit the network rate used by scp in Linux? You can use the -l option of scp to limit the rate of bandwidth. -l limit Limits the used bandwidth, specified in
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How to quite VirtualBox scale mode?
Posted onHow to quite VirtualBox scale mode? Use this hot key shortcut to quit VirtualBox scale mode Right_Ctrl + c
How to use OpenVPN together with Ovpn Spider on iPhone?
Posted onBut.. how to use the OpenVPN together with Ovpn Spider on iPhone? You can check OpenVPN + Ovpn Spider: Free VPNs for iPhone Users.
How to configure interface bonding in Linux?
Posted onHow to configure interface bonding to bound to 2 eth interfaces together in Linux, specifically CentOS/RHEL? This tutorial Configuring Interface Bonding on CentOS/RHEL/OEL 6.x introduces setting up interface bonding well on CentOS / RHEL / OEL 6.