Gionn.net

EVA Florence 2012: Open low-cost HA cluster cloud

gionn — Thu, 10 May 2012 19:14:18 +0000

During these first hot-days in Florence, I've attended the EVA Florence 2012 conference, presenting a talk with Cristiano Corsani about a project for the National Library of Florence (BNCF), covering the deployment of a small Private Cloud using exclusively open source software, for serving internal and public BNCF services.

The proposed solution includes a virtualization stack running on commody hardware, using the Linux KVM hypervisor, managed by Proxmox 2.0 and with a GlusterFS shared storage.

I hope to write down some article to share the most interesting bits of this configuration, but time is not our friend.

Using Hurricane Electric tunnel to provide IPv6 connectivity to your entire LAN

gionn — Sat, 28 Apr 2012 11:03:10 +0000

Few days ago Hurrican Electric launched a new project about a certification process involving some online tests to prove people that they are able to understand how IPv6 works and be able to correctly configure it.
Beside getting IPv6 connectivity through an IPv6 tunnel, I've easily achieved how to provide IPv6 connectivity to an entire LAN network using an unique tunnel.

cannot create zfs volume: one of the devices is part of an active md or lvm device

gionn — Sun, 22 Apr 2012 13:32:00 +0000

During the migration of a RAID1 mdadm on Ubuntu server to a ZFS mirror, I got stuck at the initial zfs volume creation with the following error:

cannot create 'tank': one or more vdevs refer to the same device, or one of the devices is part of an active md or lvm device

Obviously I've removed the device from the old mdadm array with:
sudo mdadm /dev/md3 --set-faulty /dev/sdb3 sudo mdadm /dev/md3 --remove /dev/sdb3

zram on Debian/Ubuntu for memory overcommitment

gionn — Sun, 11 Mar 2012 20:41:13 +0000

In recent Linux releases, it's available a tiny module called zram, that permits us to create RAM based block devices (named /dev/zramX), which will be kept in memory as compressed data. These ram-based block devices allow very fast I/O, and compression provides a reasonable amounts of memory saving.

We can use it as a drop-in replacement for the well-known tmpfs (used for speeding up compilation tasks or for /tmp), or better as a primary swap device, that will lead to virtually increase memory capacity, at the expense of a slightly increased CPU usage to compress/decompress the swapped data.

Nowadays RAM is very cheap, so why bother with compression? Because there are some situations where you can't upgrade memory (netbooks) or you want to over-commit real resources (virtualization hosts).

Open@BNCF - LinuxDay 2011 a Pisa

gionn — Sat, 22 Oct 2011 17:21:02 +0000

This year I've joined the LinuxDay of Pisa with a talk about my recent works in LiberSoft to the BNCF.

These includes:
* Desktop migration to Ubuntu Linux (10.04 LTS) with centralized login management (OpenLDAP) and shared /home with MooseFS;
* OpenNebula KVM-based Cloud with MooseFS as backend storage (and publishing of the relative transfer manager: https://github.com/libersoft/opennebula-tm-moosefs);
* GlusterFS-based infrastructure for the national italian legal deposit of books (italian article: http://www.bncf.firenze.sbn.it/pagina.php?id=212&rigamenu=Magazzini%20Di...)

ZFS + GlusterFS on Linux

gionn — Sat, 27 Aug 2011 09:44:02 +0000

Time is almost ripe for start using the native ZFS port on Linux (http://zfsonlinux.org/), and to increase the performances, reliability and space usage of our affordable distributed opensource storage solution.

Installing ZFS on Debian/Ubuntu is straightforward: you need first to build the SPL (Solaris Porting Layer) and after ZFS itself.

Download the latest SPL package, unpack it and build:

sudo apt-get install build-essential gawk alien fakeroot linux-headers-$(uname -r) ./configure make deb dpkg -i *.deb

Ubuntu fast boot and application launch with SSD Storage

gionn — Sun, 07 Aug 2011 14:24:36 +0000

Quick and dirty video of Ubuntu Natty 11.04 boot-up and applications launch of my Sony Vaio laptop with a Corsair 60GB SSD (http://twitpic.com/61y3n5)

Damned coincidence

gionn — Tue, 21 Jun 2011 21:24:52 +0000

SMART error (ErrorCount) detected on host: fs
Device: /dev/sdb, ATA error count increased from 0 to 74

=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.11
Device Model: ST3500320AS
[..]
9 Power_On_Hours 0x0032 070 070 000 Old_age Always - 26286

OH wait: 26286 / 24 / 365 = 3,00068493 yr

This disk broke exactly after 3 years. WTF?

OpenNebula shared storage with MooseFS

gionn — Thu, 21 Apr 2011 17:42:03 +0000

I've written a post for the OpenNebula official blog about the usage of MooseFS as shared storage:

http://blog.opennebula.org/?p=1512

squeeze-backports repository for updated pidgin anche chromium-browser

gionn — Fri, 25 Mar 2011 18:33:23 +0000

I decided to publish on my own Debian repository some packages I've rebuilded from testing/unstable for Squeeze.

Add to your sources.list:
deb http://deb.gionn.net/ squeeze-backports main

This repository currently holds:
Pidgin 2.7.11-1~bpo60+1
Chromium 10.0.648.133~r77742-1~bpo60+1

I wouldn't assure that I will maintain this repository in the future, but for now enjoy!

Debian on Sony Vaio VPCS13V9E

gionn — Thu, 03 Mar 2011 19:59:20 +0000

After selling my macbook pro, I decided to go back to PC world and searching for something more suitable for a roadwarrior sysadmin.

I've bought a 13,3" Sony Vaio (VPCS13V9E), and I have found some rusty after having successfully installed Debian Squeeze.

Vendesi macbook pro 15'' unibody 5,1 usato

gionn — Sun, 06 Feb 2011 11:39:22 +0000

Se ci fosse qualche aspirante mac user all'ascolto, ho deciso di vendere il mio macbook pro (ironman edition) e ho inserito un annuncio su macusato.it.

~~Il prezzo fissato è di 999 €.~~ VENDUTO!

Riporto anche qui le caratteristiche hardware:

Help protecting privacy of internet users with unused bandwidth of your VPS

gionn — Sat, 05 Feb 2011 11:19:35 +0000

The internet nowadays isn't a privilege, is a right. Helping the world to get full access to it, it's a must for everyone.

If you own a server, a dedicated one or a VPS (like me, on Linode) you can use your spare bandwidth to help people that live in places where internet censorship it's the standard way to deal with information.

I've setup a tor relay to help the community to maintain a fast and stable link for tor users. To get minimal harassment, that I really don't have time to deal with, I allow no exit from my node, the tor traffic will pass on my node from a node to another one.

How to create a simple Activity Stream Weekly Digest using CCK and Views

gionn — Sun, 09 Jan 2011 16:39:17 +0000

I was researching for an easy method to publish as a single post my latest {month|week|day} activities on twitter aggregated by Activity Stream.

This is how I did it:

Welcome Drupal

gionn — Sun, 19 Dec 2010 16:01:23 +0000

Finally, I achieved to migrate my mini-tiny-shiny blog from the big-bug-bloat Wordpress platform to the fast-simply-powah Drupal.

For the import, I've used the wordpress_import module (if you use php5.3, check this), that use the WXR file generated by Wordpress->Tools->Export procedure.

Every feature I was used by on Wordpress, it's not lost because Drupal has a very large base of flexible modules. Here is a list of the most import modules I use on this site:

Android speech recognition behind NAT/firewall

gionn — Sat, 11 Dec 2010 09:57:59 +0000

For speech recognition to work on Android, you need to enable the forwarding on your firewall of the 19294 tcp port.

References: http://code.google.com/support/bin/answer.py?answer=62464

Slides corso Ubuntu Server al GOLEM (maggio 2010)

gionn — Mon, 01 Nov 2010 09:15:45 +0000

Rimettendo a posto i files dei vari documenti sparsi che si sono accumulati negli ultimi mesi, sono incappato nella slides che avevo preparato per il mini-corso di 8 ore gratuito che ho tenuto al GOLEM mesi fa, e che mi ero promesso di pubblicare da qualche parte, prima o poi.

MiniCorso_Linux_server_GOLEM_2010

OpenOffice diventa mainstream

gionn — Sat, 16 Oct 2010 11:46:06 +0000

Da pochi giorni, Microsoft ha deciso di rendere noto quanto OpenOffice sia un diretto concorrente alla loro suite da ufficio, pubblicando un video di testimonianze.

Windows Seven and WPAD (Proxy Autodiscovery)

gionn — Wed, 08 Sep 2010 20:58:59 +0000

Don't works for me.

Here a clue:

Suggestions (other than SUCKS)? Google doesn't help.

How to circumvent the 417 Expectation failed behind a Squid proxy

gionn — Tue, 07 Sep 2010 09:53:14 +0000

Many applications rely on using a special HTTP/1.1 header (Expect: 100-continue) when doing a POST, which is not happily supported by Squid.

RFC2616 says:

The purpose of the 100 (Continue) status (see section 10.1.1) is to allow a client that is sending a request message with a request body to determine if the origin server is willing to accept the request (based on the request headers) before the client sends the request body.