About "linux" on monperrus.net

by Martin Monperrus
August 30, 2018: Backup on box.com with lftp on Linux
I discover that I can automatically backup my home directory on box.com with lftp on Linux. Set up your box.com password Save your login information Create a lftp script Run the script Password If box. >>> read more
July 02, 2017: Linux on a HP Elitebook Folio G1
Tips and tricks to run Linux on Hewlett-Packard "HP EliteBook Folio G1" (from ''dmidecode | grep -i Product''). Considered distribution: Debian. Bios By default, the function keys f1 .. are disabled, which is an issue for Alt-F4 (close window), etc. >>> read more
June 10, 2017: Connecting to Microsoft Exchange Calendar from Mozilla Thunderbird
To connect to a calendar hosted on Microsoft Exchange from Mozilla Thunderbird, there are several solutions: ExQuilla, Exchange Calendar, TbSync and DavMail. >>> read more
March 02, 2017: How to index FODT and FODP files with recoll?
It is possible to index the new file formats FODT and FODP of LibreOffice with recoll. Those files are plain XML files, usable in Git. You have to add to $HOME/.recoll/mimeconf: [index] application/vnd.oasis.opendocument.text-flat-xml = execm rclxml.py application/vnd.oasis.opendocument. >>> read more
October 04, 2016: Notes on connecting to eduroam with networkmanager
Do you have problems to connect to eduroam with networkmanager? (some error messages below) One potential issue is that wpa_supplicant's driver fails, one solutions is to set, wifi-wext-only=true in section [main] of /etc/NetworkManager/NetworkManager. >>> read more
September 18, 2016: How to use recoll to index maildir folders
The Recoll desktop search tool can be used to index a maildir directory, for instance that comes from Thunderbird when the maildir format has been activated -- user_pref("mail.server.server2.storeContractID", "@mozilla.org/msgstore/maildirstore;1");). Here is how. >>> read more
September 10, 2016: SSH over VPN with openconnect and ocproxy
I have a VPN access that uses the openconnect stack. I want to access a machine on the private network via SSH. However, I don't want to route all my traffic network through VPN. Here is the solution. >>> read more
January 23, 2016: Accessing STMP on port 443 using SSLH
In order to use my Thunderbird everywhere, I want to access a SMTP server on HTTPS port 443, which is open in many networks and proxy. The solution I use sslh, an applicative protocol multiplexer. The idea is that the SSL traffic to myserver. >>> read more
September 29, 2015: One million files on Git and Github
I want to create a Github repository with 1,700,000 files. Yes, more than one million files on Git. Even worse, I want to put them in the same directory. Why? Well for creating a scientific dataset of software engineering data: a dataset of all commits of the Apache Repository. >>> read more
June 24, 2015: How-to backup your data on hubic using duplicity
Here is a small how-to to backup your data on hubic using a backup tool called duplicity. Done on a Debian box. Your mileage may vary. Howto 1. Install duplicity aptitude install duplicity python-pip # the hubic backend of duplicity requires pyrax pip install pyrax 2. >>> read more
May 10, 2015: What are Thunderbird MSF files?
I have recently dig into the *.MSF file of the Mozilla Thunderbird email client. What is the MSF file format? It's simply a file-based Mork database. Mork is a database format that has been invented by Netscape. >>> read more
April 25, 2015: Notes on troubleshooting BTRFS
I've recently come across a hard file-system error: BTRFS critical (device sda2): corrupt leaf, slot offset bad: block=43231330304,root=1, slot=47 It was on my BTRFS file system on top of an SSD (Solid-state drive). >>> read more
December 17, 2014: Linux on a HP Elitebook 820
I run GNU/Linux on my HP Elitebook 820. Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991, BIOS L71 Ver. 01.20 07/28/2014 (from dmidecode) Graphics Graphics works with the "intel" driver of xorg and the "i915" kernel module. >>> read more
January 25, 2014: Compiling: where is function "_start"?
When linking programs, by convention, function "_start" is the entry point. Hence, it has to somewhere in the object files or libraries that are linked. >>> read more
January 05, 2014: Compiling C code with dietlibc and tcc
Tcc (aka Tiny C Compiler, or tinycc) is a very lightweight C compiler. Dietlibc is lightweight libc (as opposed to GNU libc). Using a tiny C compiler and a tiny libc is a kind of software minimalism. First download tcc and install dietlibc (apt-get install dietlibc-dev). Then compile tcc as follows. >>> read more
October 09, 2012: How to change the priority order of shared libraries with ld?
On Linux, shared libraries (aka dynamically linked libraries) are handled with the ld* set of tools from libc-bin. I've recently encountered some bugs related to this, here are some raw notes on this technology. >>> read more
February 14, 2012: Installing a Samsung ML-2525W on Linux
I've just successfully installed a printer Samsung ML-2525W on two Linux machines (Debian and Ubuntu). Here is what I did. >>> read more
February 11, 2012: Running mldonkey-server in headless server and bittorrent mode
Here is a small howto (for Linux/Debian/Ubuntu) to set up mldonkey to serve large files (to "seed" files on a "seedbox" in the P2P terminology), for instance to seed scientific datasets . >>> read more
January 23, 2012: Backing-up a Gmail IMAP account
To backup an IMAP account (e.g. Gmail on imap.gmail.com), mbsync (from the isync software package) is a very good solution. It backs-up all emails in a Maildir directory. Prerequisite Install isync: $ aptitude install isync Configuration file Create a file .mbsyncrc in your home directory. >>> read more
January 16, 2012: Lightweight estimation of disk misalignment performance penalty
Modern disks have a physical sector size that is larger than 512B, but the software chain (BIOS, OS, partitioning tools) generally assumes a sector size of 512B. As a result, first, I/O requests that are smaller than the physical sector size are actually translated to larger requests. >>> read more
December 01, 2011: Notes on network printing with cups
Cups is a printing software system that supports network printing. For instance, if a machine Timoleon is connected to a USB printer, one can access Timoleon over the network to print on the USB printer. The network printing facility also holds for network printers. >>> read more
November 05, 2011: Installing Debian on Amazon EC2
It is not straightforward to install a Debian server on Amazon EC2. Indeed, Amazon provides as quick start Red Hat Linux, Suse Linux and their own Amazon Linux but not Debian linux. Fortunately, RightScale provides a very good public AMI image of Debian Squeeze (the latest stable version of Debian). >>> read more
August 26, 2011: Fixing UnknownHostException bug for jmdns on linux
Here is a description of a bug I encountered while working with jmdns. Problem Aug 26, 2011 12:16:52 AM javax.jmdns.impl.HostInfo newHostInfo WARNING: Could not intialize the host network interface on nullbecause of an error: beethoven: beethoven java.net. >>> read more
August 02, 2011: Linux on a DELL Latitude E4200
I run GNU/Linux (Debian/Ubuntu) on my DELL Latitude E4200. =====Graphics===== Graphics works perfectly with the "intel" driver of xorg. I have a nice WXGA widescreen (1280x800), I am able to use a docking station and can switch to a video projector with [[http://www.thinkwiki. >>> read more
July 12, 2011: Precisely measuring the maximal disk latency
See also http://www.monperrus.net/martin/performance-of-amazon-elastic-block-store The maximal end-to-end latency of a hard-drive is achieved with accessing a random sector (it includes transfer time). The program seeker.c published at http://www.linuxinsight.com/how_fast_is_your_disk. >>> read more
July 11, 2011: Scheduler queue size and resilience to heavy IO
My server regularly stalled, freezed and sometimes crashed under heavy write accesses (open-iscsi on root filesystem). I solved the problem by changing the scheduler and increasing the maximal I/O queue size (nr_requests). >>> read more
July 10, 2011: I/O Scheduling for SAN and Virtualization
I recently encountered performance and reliability problems using iSCSI. One of the most efficient solutions was to set the I/O scheduler to "noop". Noop is the simplest elevator/scheduler in Linux. It is based on FIFO -- first request in, first out. >>> read more
July 01, 2011: Heads and sectors for partition alignment
There are many cases where [[http://www.ibm.com/developerworks/linux/library/l-4kb-sector-disks/index.html?ca=dgr-lnxw074KB-Disksdth-LX|aligning the disk partitions yields better perfomance]], for instance for database partitions, solid-state disks (SSD), and SAN storage with iSCSI. >>> read more
June 14, 2011: Performance of read-write throughput with iscsi
I recently encountered some performance issues using iSCSI. I use the open-iscsi implementation on the client side. After hours of googling and trial and errors, here are some points related to the performance of iSCSI. >>> read more
May 22, 2011: ExpandAnimations: Exporting animations to PDF in LibreOffice/OpenOffice
No preview available >>> read more
March 26, 2011: troubleshooting gnome-power-manager and gnome-power-preferences
On a Gnome desktop on Linux, [[http://projects.gnome.org/gnome-power-manager/|gnome-power-manager]] is responsible for handling battery events and physical events (laptop lid closed, power button pressed, etc). The tool ''gnome-power-preferences'' configures it. >>> read more
August 03, 2010: Performance of key-value databases with php
I discovered recently the old key-value database paradigm and I am quite convinced. But what about the performance of different implementations? This document presents a comparison in the context of PHP. >>> read more
June 22, 2010: Linux swap on a regular file (and not a partition)
1/ creating the swap file of 512M (the size is set by parameter "count") $ dd if=/dev/zero of=/swap count=1000000 2/ configuring as swap $ mkswap /swap 3/ Adding "/swap none swap loop 0 0" to the file /ect/fstab 4/ Mounting the swap file. >>> read more
June 21, 2010: Inquiry into a complex bug involving Xorg-Intel-Linux
This document is a complete analysis of a challenging bug related to Xorg, an Intel graphics card and Linux. >>> read more
November 28, 2009: backup from ext3 to vfat with qcow2 images
It's difficult to backup data if the target filesystem of your backup is vfat (e.g. on the external hard drive of your sister), and the source is ext3. The reason is that vfat has much less features compared to ext3 (e.g. the group information). >>> read more
November 16, 2009: Backup from ext3 to vfat with rsync
Rsync is great for backuping data. However, it requires some advanced options to get a smooth backup from an ext3 filesystem to a vfat/fat16/fat32 one (e.g. >>> read more
October 10, 2009: dual head with Intel GM45 on Linux
With a new version of the kernel (2.6.28) and of Xorg (1.6.3), I am able to have a dual screen with my Intel GM45 graphics card. The monitors are plugged on the HDMI-1 and HDMI-2 ports of the docking station. >>> read more
September 11, 2009: using dejavu fonts with x11-xorg
This document presents how to use DejaVu fonts with x11: Ensure that the freetype module is loaded by X (''Load "freetype"'' in the section "Module" of xorg. >>> read more
June 26, 2009: using computer modern type1 fonts with openoffice on linux
You may want to use "Computer Modern" fonts with OpenOffice.org on Linux for several reasons: * to have a latex look'n'feel * to produce PDF files that only contain Type1 fonts (see [[http://cadlab.cs.ucla.edu/~kohcc/sigdacdrom/instruct/fonts.html]]) [[http://www.monperrus. >>> read more
March 28, 2009: lightweight powersave on linux with udev and cpufreq-set
There is a number of tools to save power on Linux by throttling the CPU(s). Some are daemon based for example cpufreqd, powernowd, powersaved, cpudyn. Some are desktop based for example kpowersave or gnome-power-manager. >>> read more
December 12, 2008: automounting usb flash drives on linux with udev and pmount
Here is a solution for automounting usb flash drives / memory sticks on linux using only udev and pmount. add a file ''automount.rules'' in ''/etc/udev/rules.d''. >>> read more
November 29, 2008: A comparison of desktop search tools on Linux
I have been needing a desktop search software for a long time. There are many tools for that, but I could not figure out which one is the best. That's why I made this comparison. >>> read more
November 22, 2008: Linux on a DELL Latitude E5400
I currently have a Dell Latitude E5400, and run Linux on it. =====Graphics===== (OK with default installation of Ubuntu 8.1 Intrepid) Graphics works perfectly with the "intel" driver of xorg (at least as of X.Org version 1.4.2). >>> read more
August 23, 2007: How to make any tunnel via any proxy
Table of Contents Problem Motivations Scheme of resolution Tools used Parameters Solutions 6.1. Assistantless 6.2. With assistant 6.2.1. SSH access on assistant (you do not need to be root) 6.2.2. Root access on assistant 6.2.3. >>> read more