How to install latest version of Calibre?

ByEric Ma

How to install latest version of Calibre? The version from my distro (Ubuntu, Linux Mint, Fedora) seem at 1.xx while the latest Calibre is already at 2.x. You may check Caibre website’s instruction: http://calibre-ebook.com/download_linux sudo -v && wget -nv -O- https://raw.githubusercontent.com/kovidgoyal/calibre/master/setup/linux-installer.py | sudo python -c “import sys; main=lambda:sys.stderr.write(‘Download failedn’); exec(sys.stdin.read()); main()”

How to install gitbook?

ByEric Ma

How to install gitbook on my own Linux box? First, install node.js following https://www.systutorials.com/qa/1268/how-to-install-node-js-on-fedora or How to install node.js on Ubuntu/Linux Mint depending on your distro. Second, install gitbook by npm to /opt/: # cd /opt/ # npm install gitbook Then, the gitbook can be invoked by /opt/node_modules/gitbook/bin/gitbook.js You may need to install the latest…

How to run gitbook on a headless server (make Calibre run in headless server)?

ByEric Ma

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…

How to config network in host (wireless network) for QEMU guest os

ByWeiwei Jia

The 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…

How to write /etc/fstab entry for –bind mounting?

ByEric Ma

How to write /etc/fstab entry for –bind mounting like mount –bind /home/hadoop/hdfs/store-tmp /home/store/tmp From man 8 mount: Since Linux 2.4.0 it is possible to remount part of the file hierarchy somewhere else. The call is mount –bind olddir newdir or shortoption mount -B olddir newdir or fstab entry is: /olddir /newdir none bind

How to change number of replications of certain files in HDFS?

ByEric Ma

The 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…

How to get logs of a specific time range on Linux?

ByEric Ma

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…

What’s the difference between Reliability, Durability, and Availability for data storage system?

ByWeiwei Jia

Some important concepts in distributed system like Hadoop distributed file system, Google file system and so on. Answer from http://www.quora.com/Whats-the-difference-between-Reliability-Durability-and-Availability-for-data-storage-system The difference between durability and availability is fairly simple. Durability is about what happens when all power goes out everywhere. Has all data been written to stable storage that doesn’t require power (e.g. disk/flash), in…