unix

Bookmarks for 30 apr 2014 through 6 mag 2014

These are my links for 30 apr 2014 through 6 mag 2014:

  • Ralentir le débit de postfix pour wanadoo/orange – Le blog de Michauko – Si vous avez un serveur d’envoi de mails (je ne parle pas d’être un spammeur) et beaucoup d’abonnés chez Wanadoo et Orange, vous risquez fort le rejet temporaire de votre serveur si le débit d’envoi est trop fort. C’est ce qui m’est arrivé et hop, 5000 mails entassés dans la file de postfix.
  • smtp-in.orange.fr refused to talk to me: postfix solution | floriancrouzat.net – Orange sadly limits inbound connexion to it’s MX to 1 connexion per IP, which is a total pain in the ass when you try to deliver newsletter, or manage a MTA. Here is a sample log from their MX: Jul 4 10:42:42 smtp.example.com postfix/smtp[32347]: 0123456789: host smtp-in.orange.fr[193.252.22.65] refused to talk to me: 421 mwinf5c34 ME Trop de connexions, veuillez verifier votre configuration. Too many connections, slow down. OFR004_104 [104] However, since they won’t change anything, we have to take mesures, here’s what you can do if you run postfix: you have to set a per-destination concurrency limit.
  • Aral Balkan: Historical Archive — How to revert (roll back) to a previous revision with Subversion – Here, then, is a very simple, plain English explanation of how to revert to a previous version of your application in Subversion, to help anyone who may be starting out with it and is lost.
  • Tmux: A Simple Start – In all likelihood, you’ve probably already heard of tmux. However, you may not be using it everyday. If tmux is on your “Someday” list because you think it is too complicated (I mean, c’mon, the word “multiplexer” is just plain scary), then I am here to show you just how easy it is to put tmux into your workflow.
  • Tyblog | Yet Another Vim Setup – Vim is an excellent text editor. I’ve used it for many years and like most vim users, have collected a fairly large collection of settings in my .vimrc and learned how to grok my vim usage effectively through a lot of trial and error. To that end, I’ve tried to assemble a useful overview of my experience with vim.

Bookmarks for 28 mar 2014 through 29 mar 2014

These are my links for 28 mar 2014 through 29 mar 2014:

  • LDAP org chart | bitcube.co.uk – For centralised authentication and authorisation, LDAP is the de-facto standard. Whether in its pure form on Unix or in Active Directory guise on Windows, everyone uses it. What many people don't realise is that you can store all sorts of useful (and not so useful) information in LDAP. One field which can be useful is the "manager" attribute. One of our customers use that and so we've written a small script to graph it using the excellent Graphviz tool. It will probably need customising for specific cases, however we hope that people find it useful nonetheless. If you want to alter the output, do have a look at the record format documentation.
  • Puppet errors explained | bitcube.co.uk – Puppet is a wonderful system automation tool, however the learning curve can be a little steep. We've collected some of the errors messages and "strange" behaviour you may come across together with explanations to help overcome these hurdles and boost adoption of this fabulous tool. If you have any useful errors and explanations, please do send them in and we'll update this article.
  • SCAP: Guide To The Secure Configuration of Red Hat Enterprise Linux 5 – This guide has been created to assist IT professionals, in effectively securing systems with Red Hat Enterprise Linux 5.
  • DNS Load Balancing and Using Multiple Load Balancers in the Cloud – […] Load balancing in general is a complicated process, but there's some secret sauce in managing DNS along with multiple load balancers in the cloud. It requires that you draw from a few different sets of networking and “cloudy” concepts. In this second article in my best practices series (my first post covered how to use credentials within RightScale for storing sensitive or frequently used values), I'll explain how to set up load balancers to build a fault-tolerant, highly available web application in the cloud. Here's what you’ll need: Multiple A records for a host name in the DNS service of your choice Multiple load balancers to protect against failure […]
  • gdnsd – gdnsd is an Authoritative-only DNS server which does geographic (or other sorts of) balancing, redirection, weighting, and service-state-conscious failover at the DNS layer. gdnsd is written in C using libev and pthreads with a focus on high performance, low latency service. It does not offer any form of caching or recursive service, and notably does not support DNSSEC. There's a strong focus on making the code efficient, lean, and resilient. The code has a decent regression testsuite with full branch coverage on the core packet parsing and generation code, and some scripted QA tools for e.g. valgrind validation, clang-analyzer, etc. The geographically-aware features also support the emerging EDNS Client Subnet draft for receiving more-precise network location information from intermediate shared caches.

Bookmarks for 25 mar 2014 through 28 mar 2014

These are my links for 25 mar 2014 through 28 mar 2014:

  • blblack/gdnsd – gdnsd is an Authoritative-only DNS server. The initial g stands for Geographic, as gdnsd offers a plugin system for geographic (or other sorts of) balancing, redirection, and service-state-conscious failover. The plugin system can also do things like weighted address/cname records. If you don't care about these features you can ignore them :).
  • How to Create and Apply Patches in GIT using diff and apply Command – Creating a patch in GIT is a great way to share changes that you are not yet ready to push to a public branch of a project.
  • Your own Dynamic DNS in 3 steps | The Nexus – This is a "niche" post: it will really only appeal to you if you have access to your own — or a friend's — name servers and want to use your own domain to track your dynamic IP addresses, such as your home router's. You will still have to buy your own domain, cheap if you go to internet.bs or namecheap.com. I hear that the latter even provide their own dynamic DNS service although I cannot tell you anything about its quality/flexibility. So, why this post? It's for you, my friends, budding entrepreneurs who wish to bootstrap your business and know that every cent counts. Maybe you feel that you could host your product's web site on a home computer. Maybe you need more control over what happens on that server. Or maybe you want to be able to log on to your development machine from anywhere in the world. Whatever your reasons, you're still here. So let's get started.
  • Apache – Prefork or Worker | Code Bucket – Apache is the most common and famous webserver. Everyone knows about apache and most of us also have hands on experience with apache. But few of us know that apcahe2 comes with 2 multi processing modules(MPMs): 1. Prefork 2. Worker
  • Ottimizzazione di Apache, dall’analisi ai parametri – […] I recenti sviluppi nel campo della virtualizzazione hanno accelerato la moltiplicazione di ambienti virtuali vps a basso costo, molto convenienti ma a volte carenti dal punto di vista delle risorse di sistema. Molto spesso questi ambienti vengono utilizzati a scopo di testing o come ambienti di produzione all'interno dei quali viene implementato l'utilizzo di un web server. Apache, come ben sappiamo ,e uno dei web server piu diffusi e nella maggioranza dei casi rappresenta la scelta di default su un grandissimo numero di installazioni […]

Bookmarks for 8 ago 2013 through 12 ago 2013

These are my links for 8 ago 2013 through 12 ago 2013:

  • Shuttle | A simple SSH shortcut menu for OS X – A simple SSH shortcut menu for OS X
  • Unix FAQ/shell Index –
  • Portable Shell – Autoconf – When writing your own checks, there are some shell-script programming techniques you should avoid in order to make your code portable. The Bourne shell and upward-compatible shells like the Korn shell and Bash have evolved over the years, and many features added to the original System7 shell are now supported on all interesting porting targets.

Bookmarks for 15 gen 2013 through 16 gen 2013

These are my links for 15 gen 2013 through 16 gen 2013:

  • Simplify Advanced Shell Scripting With Ruby | AIX | IBM Systems Magazine | System p, System p5, Power System | Ruby, SSH, shell scripting, Bull Freeware, sysadmin, – IBM Systems Magazine – Ruby is just for experienced programmers. right? False! Originating in the mid-1990s, Ruby is a fantastic language, made popular recently by the Web application framework—Ruby on Rails. It’s a massively flexible and easy language to learn. You can find Ruby for AIX in the AIX Toolbox at the Bull Freeware. The script we’ll be creating will do the following:

     

    * Go through a large list of servers.
    * SSH them and determine whether the server is AIX.
    * If so, it will go through all disks, returning their type.
    * It will do all of this completely in parallel in batch at 25 sub-processes at a time.

  • Recovering a lost partition table with a VMFS volume | vInfrastructure Blog – Vi possono essere diversi motivi che portano alla perdita della tabella delle partizioni o alla sua corruzione. Nel caso di datastore VMFS le possibili cause sono: resignature da un altro sistema (ad esempio il backup server, nel caso funzioni in SAN mode), un errore umano (basta eseguire, su dischi condivisi, da vSphere Client un Datastore / Delete da un ESXi non ancora collegato al vCenter Server), o anche a causa di qualche problema lato storage (mi è capitato proprio questo caso di recente su uno storage entry level)[…]

    (Mi è capitato, ho seguito la kb di vmware e ne sono uscito. Comunque sto sudando ancora adesso…)

  • DataFart – DataFart lets you easily graph data from the command line.

Bookmarks for 20 dic 2012 through 21 dic 2012

These are my links for 20 dic 2012 through 21 dic 2012:

  • ROOTVG.NET AIX Hints and Tips – Frequently Asked Questions (FAQ) from the AIX User and System Administrator Courses.
  • http://archive.rootvg.net/adminquickref.htm – Quick Reference Administering AIX V5.2 version 1.0
  • MaxClients, MaxKeepAliveRequests e KeepAliveTimeout: ottimizzazione di Apache HTTP Server | Panix websiting – Oggi sappiamo quanto sia importante la velocità di caricamento della pagina sia in termini di usabilità ed user experience, sia in termini SEO, in quanto i motori di ricerca hanno inserito la velocità di caricamento delle pagine nei loro algoritmi di ranking.

    Di recente ho avuto modo di lavorare sull'ottimizzazione di un server web, ed è interessante notare come sia possibile ottenere ottimi risultati intervenendo su tre semplici parametri di configurazione del web server Apache:

    MaxClients
    MaxKeepAliveRequests
    KeepAliveTimeout
    parametri la cui importanza è spesso sottovalutata e che non sempre garantiscono le migliori prestazioni alle loro impostazioni di default.

Bookmarks for 29 nov 2012 from 15:24 to 16:55

These are my links for 29 nov 2012 from 15:24 to 16:55:

  • PowerShell Commands (CMDLETs) for Active Directory by Quest – The ActiveRoles Management Shell for Active Directory is a set of free, predefined commands for Windows PowerShell, the powerful command line and scripting language developed by Microsoft. These commands are designed to help administrators automate common, repetitive and bulk management tasks for Active Directory, such as creating, removing or updating objects in AD.
  • PowerGUI.org – Free Windows Powershell Community – Welcome to PowerGUI.org – a free community for PowerGUI, a graphical user interface and script editor for Microsoft Windows PowerShell!
  • ksh_timer – An interface to evaluate function execution time in shell script in each function or in user-defined sections

    Summary:  ksh_timer helps ksh script developers or administrators to find out quickly and with minimal change in their script, what functions or user-defined sections are time consuming. By default, ksh_timer will time the overall script and each function defined and used in the script. Users can define additional sections of the scripts they need to be timed.

Bookmarks for 2 nov 2012 from 15:23 to 18:09

These are my links for 2 nov 2012 from 15:23 to 18:09:

  • USEFUL ONE-LINE SCRIPTS FOR SED – (Unix stream editor) Dec. 29, 2005
    Compiled by Eric Pement – pemente[at]northpark[dot]edu version 5.5
  • IBM devscan tool – United States – The devscan tool is a supplemental tool used by AIX support personnel to gather debugging data for Storage Area Networks. The package download includes a manual page that is also available on this site at the Usage tab.
  • mysqlreport :: Make easy-to-read MySQL status reports – mysqlreport makes a friendly report of important MySQL status values. mysqlreport transforms the values from SHOW STATUS into an easy-to-read report that provides an in-depth understanding of how well MySQL is running. mysqlreport is a better alternative (and practically the only alternative) to manually interpreting SHOW STATUS.
  • Percona Online Tools – Welcome to Percona's suite of productivity tools for MySQL database administrators and developers. One free account lets you access all of the tools below, and keeps you updated when new tools or enhancements are available. Registration is required.

    Optimize your MySQL Server:
    Leverage our expertise to create a good starting configuration for a MySQL server.
    This tool will walk you through all of the steps necessary to create a ready to use MySQL configuration file in about 5 minutes.

    Analyze an SQL Query:
    Find out when your SQL is potentially buggy, hard for MySQL to optimize, or confusing.
    This tool will analyze your SQL code and warn you when it detects problems that we've encountered while optimizing thousands of queries in real applications.

Bookmarks for 3 set 2012 through 5 set 2012

These are my links for 3 set 2012 through 5 set 2012:

  • OneLook Reverse Dictionary – How do I use OneLook's reverse dictionary feature?

    OneLook's reverse dictionary lets you describe a concept and get back a list of words and phrases related to that concept. Your description can be a few words, a sentence, a question, or even just a single word. Just type it into the box above and hit the "Find words" button. Keep it short to get the best results. In most cases you'll get back a list of related terms with the best matches shown first.

    [ via http://blog.terminologiaetc.it/2012/09/04/onelook-reverse-dictionary/ ]

  • missing disks, dump devices, mirroring, etc. – Waldemar Mark Duszyk – Since, we are pretty much always learning …. Some of us on a more elementary, intermediate, or advanced level but regardless of the level we all always learn or re-learn (because what we have mastered we had an ample time to forget – not doing it for a while), here it is a reminder of how to deal with a volume group (in this case it is rootvg which for some reasons lost one of it disks. The loss could be a function of SAN, VIO or other event. It could be a permanent loss – a disk is dead, broken, no longer functioning or the loss was/is temporary in nature; AIX kernel detected a timeout (without any disk errors associated with device failure) long enough for the kernel to mark the disks missing.
  • Authenticating RedHat with ActiveDirectory and Kerberos – Waldemar Mark Duszyk – One of my previous posts deals with authentication of RedHat LINUX using Tivoli Directory Server (TDS LDAP). As I was working on this project, my colleague Igor was busy configuring RedHat authentication with Active Directory and Kerberos (already configured on AD).