When I tried to apply new configuration in /etc/sysctl.conf, I got following message. warning: /etc/sysctl.conf(44): invalid syntax, continuing… Sounds like your changed /etc/sysctl.conf has problem. You may post the content of your /etc/sysctl.conf here to let other have a check. net.ipv4.ip_forward = 0 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.default.accept_source_route = 0 kernel.sysrq = 0 kernel.core_uses_pid = 1
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Tag: configuration
how change my policy of scheduling in hadoop?
Posted onI want to change policy of scheduling in Hadoop, how to I can change job order in map reduce automatically. Assume you are using Hadoop 2 / YARN. The configuration parameter named yarn.resourcemanager.scheduler.class controls the class to be used as the resource scheduler for YARN/Hadoop. The default value for the scheduler class (check more at
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How to configure ifcfg-eth0 network scripts on Fedora/RHEL Linux?
Posted onHow to configure the ifcfg-* network script files under /etc/sysconfig/network-script/ on Fedora/RHEL Linux? Following is a very typical ifcfg-eth0 file setting static IP/gateway/network mask: DEVICE=eth0 BOOTPROTO=none ONBOOT=yes NETMASK=255.255.0.0 IPADDR=192.168.1.151 GATEWAY=192.168.1.10 USERCTL=no More options are supported, here you can find a reference: Interface Configuration Files (a easier to read PDF from F15 doc).
How to open a URL in a new window in JavaScript?
Posted onHow to open a URL in a new window in JavaScript? For example, to open a new window to browse “http://www.systutorials.com“. Open the URL in a new window: url = “http://www.systutorials.com”; window.open(url); Some browser will open the window in a new tab depending on the configuration. If you want to force the browser to open
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How to force ssh client to authenticate using password on Linux?
Posted onssh client can use many authentication methods like password, keys. On a server, I set password-less log in with private/public key. Now, I want to try whether the new password is set correctly by log on using ssh. By default, the key-based authentication method is used again. How to force ssh client to authenticate using
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How to allow websites’ .htaccess files in Apache2?
Posted onHow to allow websites to use .htaccess files in Apache2 web servers? The AllowOverride directive controls this: http://httpd.apache.org/docs/current/mod/core.html#allowoverride To allow AllowOverride in a directory, add the following rules to the /etc/httpd/conf/httpd.conf or similar configuration file for your apache installation: <Directory “/var/www/www.example.com”> Options FollowSymLinks # # AllowOverride controls what directives may be placed in .htaccess files.
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How to enable SSH service on Fedora Linux?
Posted onHow to enable SSH service on Fedora Linux? By default, it seems ssh is not enabled. Fedora may not have sshd service installed/enabled by default. You will need to install and configure it by yourself. The following instructions is for Fedora 22 as an example. First, install the sshd server by # dnf install openssh-server
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How to make Fedora Linux not clean some files in /tmp/?
Posted onOn my Fedora 20, I find that the system automatically clean up file under /tmp/. This is convenient. However, it cause some problems for some programs. For example, HDFS puts its DataNode pid file under /tmp/ by default like hadoop-hadoop-datanode.pid. After it is cleaned up, the hadoop-daemon.sh script will consider there is no DataNode running.
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How to mount LVM volume from an external hard disk on CentOS?
Posted onOn Fedora, after inserting/plugging in an exteranl hard disk with LVM partitions on it, the partitions will appear under /dev like /dev/lvm-group/lvm-partition. However, on CentOS 6, the LVM volumes do not appear automatically. How to mount LVM partitions from an external hard disk on CentOS? What you need on CentOS is to activate the LVM
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What about the master branch for local git configuration in a git repository to make it track remote master branch?
Posted onWhat about the master branch for local git configuration in a git repository to make it track remote master branch? You may append these lines to .git/config in your cloned repository directory: [branch “master”] remote = origin merge = refs/heads/master
Good Cinnamon theme for Fedora 21 Linux?
Posted onAny suggestion on good theme configuration for Fedora 21 Linux? My favorite combination of Window borders, Icons, Controls, Mouse Pointer and Desktop is as follows. All packages and themes are from Fedora repository or the Cinnamon repository. Remember to set the cursor theme for QT application like Google Chrome following: https://www.systutorials.com/4068/configuring-mouse-cursor-style-for-qt-applications-in-gnome-mate-desktop/ For this configuration, the
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How to make Linux automatically reboot after a kernel panic?
Posted onAfter a kernel panic, it is impossible to remotely connect to the Linux server to reboot it by SSH. How to make the panic kernel automatically reboot itself? Linux kernel has a nice feature that reboots itself after a timeout when a kernel panic happened. Usually, it is disabled by default. To turn it on,
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How to enable RPM Fusion for CentOS 6.6?
Posted onHow to enable RPM Fusion for CentOS 6.6? Enable RPM fusion on RHEL 6 or compatible like CentOS: su -c ‘yum localinstall –nogpgcheck http://download1.rpmfusion.org/free/el/updates/6/i386/rpmfusion-free-release-6-1.noarch.rpm http://download1.rpmfusion.org/nonfree/el/updates/6/i386/rpmfusion-nonfree-release-6-1.noarch.rpm’ It will install https://fedoraproject.org/wiki/EPEL. If it fails to install EPEL automatically, you will need to install it manually. Reference: http://rpmfusion.org/Configuration
Basic iptables configuration for Linux
Posted onWhat is a good basic iptables config? Basic rules needed: Allow incoming TCP to 22 for SSH but blocks all others. Allow outgoing TCP/UDP connections. You may consider using the following rules as a start: for tables in iptables ip6tables ; do # Flush existing rules $tables -F # Default policy $tables -P INPUT DROP
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How to configure iptables on Linux Mint 17.1?
Posted onHow to configure iptables and make the configuration persistent across system restarting on Linux Mint 17.1? You can use the ‘iptables-persistent’ tool. To install iptables-persistency pachage: sudo aptitude install iptables-persistent The you can manipulate the iptables by the ‘iptables’ command. To save the current iptables rules: sudo /etc/init.d/iptables-persistent store It will store the rules for
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How to pull your git tree after creating it on remote server
Posted onCurrently, I have created my branch dev-harry but I cannot pull it successfully as follows. harryxiyou@common_vm ~/forest/kvplus/kvplus $ git branch * dev-harry master rc harryxiyou@common_vm ~/forest/kvplus/kvplus $ git pull You asked me to pull without telling me which branch you want to merge with, and ‘branch.dev-harry.merge’ in your configuration file does not tell me, either.
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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 change an running HDFS cluster’s replication factor?
Posted onNow, I have a running HDFS cluster storing lost files. I want to change its default replication factor. How to change it? What will happen after it is changed? For example, I change from 2 to 3. Will HDFS automatically re-replicate the data chunks? First, the replication factor is client decided. Second, the replication factor
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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 make Thunderbird check for new messages in all IMAP folders?
Posted onHow to make Thunderbird check for new messages in all IMAP folders? Under “Edit/Tools > Options > Advanced”, click the “Config Editor” button. In the config editor, set the mail.check_all_imap_folders_for_new configuration to “true“.