21 Ago 14 How to enable apache NameVirtualHost with SSL
If you want to create name based virtualhosts in apache with SSL Certificates, you need openssl with SNI and TLS support (0.9.8f or better) and good apache 2.2.X version.
It’s a simple task, after you’ve read this official article: https://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI
12 Giu 14 How to declare a read only variable in bash
I didn’t know that it was possible to declare a read only variable in bash.
It’s as simple as to run the following statement:
declare -r a=10
This will create a read only variable called $a with value 10 that you cannot overwrite or unset.
Cool!!
05 Dic 13 As you can see, this site is reachable via IPv6!
If you are using IPv6 (like me) you can see that this blog is reachable via IPv6. Pretty cool!
14 Nov 13 LVM Hot backups with snapshot
As you may know, LVM make it possible to create live snapshots of running logical volumes.
Imagine a guest virtual machine that has its virtual disk backed on a LVM logical volume on the host system.
You may create a live hot backup of your virtual machine on the fly, while it is working.
To do this, I created a small script that makes a compressed backup of all the logical volumes on the /dev/vg0 volume group.
The script make use of the standard LVM utilities to have the snapshot, the pv utility to get a cool progress bar and pigz utility to compress (gzip) using all of your processors.
If everything went ok, when the script finishes you’ll find your LVM hot backups on the /backups directory, and the temporary lvm snapshots removed.
This is how I make hot backups of some of my virtual machines (lvm_hot_backup.sh):
#!/bin/bash
for lv in `lvdisplay /dev/vg0 | grep ‘LV Name’ | awk ‘{print $3}’`
do
LV_SIZE=”`lvs –units m –noheadings –nosuffix $lv | cut -d’ ‘ -f7 | cut -d. -f 1`” # LV size in MB
LV_UUID=”`lvdisplay $lv | grep ‘LV UUID’ | awk -F’LV UUID’ ‘{print $2}’ | sed ‘s/^ *//g’`”
LV_SNAPNAME=”SNAP_`basename $lv`”echo “LVM Logical Volume: $lv”
echo “Size: $LV_SIZE MB”
echo “UUID: $LV_UUID”
echo “Snapshot name: $LV_SNAPNAME”
echo “Removing old snapshot (if any)…”
lvremove -f “/dev/vg0/$LV_SNAPNAME”
echo “Creating snapshot…”
lvcreate -L+2G –snapshot -n”$LV_SNAPNAME” “$lv”
sleep 4
echo “Backing up snapshot…”
dd if=”/dev/vg0/$LV_SNAPNAME” bs=512k of=/dev/stdout | pv -pterbW -i 2 –buffer-size 512k –size “$LV_SIZE”m | /usr/bin/pigz -9 -b 256 > “/backups/$LV_SNAPNAME.lv.gz”
echo “Removing snapshot…”
lvremove -f “/dev/vg0/$LV_SNAPNAME”
echo “–”
done
03 Nov 13 SSH connection is slow? Did you try to disable DNS lookups?
If your SSH connection is slow, it may depends on your SSH server that is executing reverse DNS lookups to try to identify your details.
Try setting the parameter below to your /etc/ssh/sshd_config and restart your ssh server daemon:
UseDNS no
It worked perfectly for me, it may work perfectly with you too.
10 Ott 13 How to fix svn error: OPTIONS ‘https://1.2.3.4/svn/prj’: SSL handshake failed: SSL error: Key usage violation in certificate has been detected
If you encounter an error like this one on your SVN client:
svn: OPTIONS di ‘https://192.168.1.36/svn/myprj‘: SSL handshake failed: SSL error: Key usage violation in certificate has been detected. (https://192.168.1.36)
you can try to fix your problem linking your libneon-gnutls.so.27 library used by your svn client to /usr/lib/libneon.so.27.
Try with this one:
mv /usr/lib/libneon-gnutls.so.27 /usr/lib/libneon-gnutls.so.27.old
ln -s /usr/lib/libneon.so.27 /usr/lib/libneon-gnutls.so.27
Tested on Debian 6.0 and Ubuntu 11.10
03 Mar 13 How to install php 5.2 on debian squeeze (6.0.x), the debian way
You may know that the PHP version coming with debian squeeze is 5.3. Since the 5.3 version of PHP breaks some compatibility with 5.2 you may find that an old PHP application is no longer working with the new version of PHP on squeeze.
The steps required to install PHP 5.2 on debian squeeze are very simple, you just need to setup APT to install the PHP packages coming with debian lenny.
The first thing to do is to add the lenny repository to the end of /etc/apt/sources.list:
deb http://archive.debian.org/debian lenny main contrib non-free
Then you need to make sure that your favourite PHP packages will be downloaded from lenny instead of squeeze. You can do this creating the file /etc/apt/preferences.d/lenny, with this stuff inside:
Explanation: choose Lenny as installation source if the package is not already installed and not available from Squeeze
Package: *
Pin: release n=lenny*
Pin-Priority: 100Explanation: choose Lenny as installation source for those packages
Package: libapache2-mod-php5 php5-common php5-curl php5-gd php5-mcrypt php5-mysql php5-cli php5-mhash php5-xsl php5-imap php5-xmlrpc php5-sqlite
Pin: release n=lenny*
Pin-Priority: 999
After that, remove any previously installed PHP 5.3 package, for example with the command
apt-get remove –purge php5\*
and then install the PHP 5.2 packages from lenny:
apt-get update
apt-get clean
apt-get install libapache2-mod-php5 php5-common php5-curl php5-gd php5-mcrypt php5-mysql php5-cli php5-mhash php5-xsl php5-imap php5-xmlrpc php5-sqlite
That procedure saved my life twice, I hope it will save yours too!
02 Dic 12 New NuvolaBase Dashboard
Tonight at 03.00 GTM the NuvolaBase team publicly released the new NuvolaBase Dashboard.
As you may know, with NuvolaBase you can handle your private database on the cloud.
The new dashboard aims to be simple, stable and powerful. You can login using your google, twitter, facebook, linkedin account.
In the next days the NuvolaBase guys will release many new cool features like a powerful REST API to handle your databases in the cloud from your application.
This is the official article on the NuvolaBase blog: http://nuvolabase.blogspot.it/2012/12/nuvolabase-dashboard-upgrade.html
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