Linux Kernel 4.9.60 Release

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This post summarizes Linux Kernel new features, bugfixes and changes in Linux 4.9.60 Release. Linux 4.9.60 Release contains 24 changes, patches or new features. In total, there are 64,224 lines of Linux source code changed/added in Linux 4.9.60 release compared to Linux 4.9 release. To view the source code of Linux 4.9.60 kernel release online,
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Release Notes For Linux v2.0

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This is the release notes for linux release v2.0 (source code: linux-2.0.tar.gz) with format adjusted by removing/replacing tabs/spaces/new lines/formatting marks. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post. Intro This document contains a list of
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Release Notes For Linux v1.0

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This is the release notes for linux release v1.0 (source code: linux-1.0.tar.gz) with format adjusted by removing/replacing tabs/spaces/new lines. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post. CHANGES since 0.99 patchlevel 15: removed all the
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Linux Kernel 4.19.70 Release

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This post summarizes new features, bugfixes and changes in Linux kernel release 4.19.70. Linux 4.19.70 Release contains 95 changes, patches or new features. In total, there are 101,521 lines of Linux source code changed/added in Linux 4.19.70 release compared to Linux 4.19 release. To view the source code of Linux 4.19.70 kernel release online, please
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Linux Kernel: fs: handle SEEK_HOLE/SEEK_DATA properly in all fs’s that define their own llseek

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This change “fs: handle SEEK_HOLE/SEEK_DATA properly in all fs’s that define their own llseek” (commit 06222e4) in Linux kernel is authored by Josef Bacik <josef [at] redhat.com> on Mon Jul 18 13:21:38 2011 -0400. Description of “fs: handle SEEK_HOLE/SEEK_DATA properly in all fs’s that define their own llseek” The change “fs: handle SEEK_HOLE/SEEK_DATA properly in
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Allowing root Access to NFS Directories

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For local filesystems, root usually has full access (read/write) to directories/files inside of it. But for NFS directory mounted from network, root usually has no permission to write to directories or files within the NFS directory. How to make root act similarly in an NFS directory to the behavior in local directories? The reason that
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How do I force Linux to unmount a filesystem?

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Some time, Linux fails to unmount a filesystem reporting “device is busy”. I understand that this helps avoid data lost by disallowing unmouting a filesystem when it is being used. But for some situations, I am sure there is something wrong happened or I care not data lost, such as a NFS mounting while the
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How to force umount a NFS directory on Linux?

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The NFS server is down. It is reported “Stale NFS file handle”. I tried ‘umount’ and ‘umount -f’. But neither succeeded. # umount /mnt/store umount.nfs: /mnt/store: Stale NFS file handle # umount -f /mnt/store umount.nfs: /mnt/store: Stale NFS file handle How to force umounting the NFS without rebooting the Linux server? I usually have to
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How to get logs of a specific time range on Linux?

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The 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 Export an NFSv4 Server to External Networks

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We ever discussed fixing ports used by NFSv3 so that it can be easily exported to external networks. For NFSv4.1 or higher, things are much easier. The ports for mountd, statd, and lockd are not required in a pure NFSv4 environment. We have less ports to control or allow for connections. Only port 111 and
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Forcing Linux to Unmount a Filesystem Reporting “device is busy”

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Linux may report “device is busy” when we try to umount a filesystem. This behavior is reasonable as it can help us avoid data loss by disallowing unmouting a filesystem when it is being used. But for situations when we are sure there is something wrong happened or we care not data lost such as
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Controlling Filesystem Mounting on Linux using /etc/fstab

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Controlling the mounting of filesystems is a useful technique for managing Linux systems. The mounting configurations are mostly in the /etc/fstab file. In this post, we will discuss 2 common and useful techniques for controlling the filesystem mounting by playing with the /etc/fstab file: allowing non-root users to mount/unmount filesystems and avoiding mounting failures blocking
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Fixing Ports Used by NFSv3 Server

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The ports used by NFS server can be dynamically assigned by rpbind to any higher number. We need to fix the ports used by NFS server to configure firewall or port forwarding mechanism. The ports used by NFS server and how to fix these ports will be introduced in this post. There are seven ports
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Unified Linux Login and Home Directory Using OpenLDAP and NFS/automount

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In this post, how to unified Linux login and home directory using OpenLDAP and NFS/automount will be introduced. 0. System environment This solution is tested on Fedora 12 systems and CentOS 5. LDAP and NFS server: IP: 10.0.0.2 OS: Fedora 12 x86_64 ldap base dn: “dc=lgcpu1″ Clients: IP: 10.0.0.1/24 OS: Fedora 12 x86_64 1. LDAP
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How to Set Up and Configure NFS Server and Clients

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NFS is widely deployed and used even after more than twenty year. NFS is easy to set up and easy to use. This introduces how to set up the NFS server and clients. We use the Fedora system as the example. The tutorial here is for RHEL/CentOS/Fedora and derived Linux OSes. Set up an NFS
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Linux Cluster Solutions

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Solutions to Linux cluster construction and management such as unified account management, NFS home directory, network configurations are summarised in this post. The post is keeping updating while new solutions is added to this site. ===Account and storage management=== [[unified-linux-login-and-home-directory-using-openldap-and-nfsautomount|Unified Linux Login and Home Directory Using OpenLDAP and NFS/automount]] [[backup-linux-home-directory-using-rsync|Backup Linux Home Directory Using rsync]]
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Setting Up a NFS Server on Top of tmpfs /dev/shm

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tmpfs has blazing speed. Why not set up a high speed NFS server on top of tmpfs? A little trick is required for setting NFS server on top of /dev/shm. If we add a normal entry in /etc/export and them run # exportfs -a exportfs will give us a warning like this: exportfs: Warning: /dev/shm
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