Slash Dot Dash

Just fixed an issue with openssl not working correctly with Ruby 1.8.6 (installed from source) on Ubuntu Feisty (server).

$ cat /etc/issue
Ubuntu 7.04

After deploying a new Rails application I restarted mongrel but all requests were returning errors (500); the production.log indicated the following issue:

no such file to load -- openssl

To rectify this I had to do the following.

$ sudo apt-get install libopenssl-ruby
$ sudo apt-get install libssl0.9.8

$ cd ~/src/ruby-1.8.6/ext/openssl
$ ruby extconf.rb 
$ make
$ sudo make install

To test that openssl is working correctly use irb:

irb(main):001:0> require 'openssl'
=> true

References

• http://linuxbrit.co.uk/rbot/ticket/69

• http://www.ruby-forum.com/topic/90083

The blog is back up again (also moved to the root of the domain) – and hopefully running quicker now thanks to a quick change of hosting setup (Apache and fcgi to pound proxying to mongrel_cluster).

One quick note to anyone experiencing the following problem with Typo running on Debian Linux:

Lost connection to MySQL server during query

The recommended ‘fix’ is to gem install mysql. Doing that on a Debian machine will result in numerous errors unless you also do the following:

$ apt-get install libmysqlclient10-dev
$ gem install mysql

(Thanks to the owner of this blog for the pointer, found via google).

/var/cache/apt/archives can build up a lot of cruft…

Clear out package files no longer available:

apt-get autoclean

Clear out all downloaded package files:

apt-get clean

RAID5 software arrays in Linux are very simple to setup and should run smoothly. Inevitably something will go wrong – but luckily that’s why we use RAID5 – there should be no data loss.

Software RAID HOWTO is the best reference.

Check the RAID

Identify the problematic disk [UU_]

mdadm --detail /dev/md0
cat /proc/mdstat

Remove failed disk

mdadm /dev/md0 -r /dev/hdg1

Add new disk

mdadm /dev/md0 -a /dev/hdg1

Once rebuilding has started you can check the status via /proc/mdstat (depending on the array size it may take quite a long time).

cat /proc/mdstat 
Personalities : [raid5] 
md0 : active raid5 hdg1[3] hdc1[0] hde1[1]
      488391680 blocks level 5, 128k chunk, algorithm 2 [3/2] [UU_]
      [>....................]  recovery =  0.8% (2098944/244195840) finish=205.3min speed=19648K/sec
unused devices: <none>