SSD in a ThinkPad T61p

This week I purchased a OCZ Vertex 2 SSD drive for my laptop, a Lenovo ThinkPad T61p. After replacing the old HDD, I was greeted by the following error message, just after the BIOS screen:

2100: HDD0 (Hard Disk Drive) initialization error (1)

That does not sound good. Anyway, I searched around and found one simple advice:

Don’t use the ThinkPad HDD cage and the corresponding anti-shock bumpers. The problem lies with the physical connection of the SSD. I inserted the SSD without the bumpers and the bracket and voilĂ  : It worked flawlessly.

The SSD does not need shock-protection from the rubber bumpers, but in order to stabilise the drive I put some padding at the end of the SSD, so there is no stress on the connectors.

XCache – A booster for WordPress

I was not pleased with the results of my database tweaks. So I looked further to improve the performance of this blog and stumbled upon XCache. Developed by the same people that created lighttpd, XCache is a PHP opcode cacher that greatly improves WordPress performance.

Using the same Java program I used in my previous tests, I queried the website 500 times and packed the data into a graph. This is what showed up:

Graph showing xcache performance impact

Now that is what I am talking about! The query time is nearly three times as fast as before.

I am still looking into other cachers like Alternative PHP Cache (APC), but I like xcache so far.

Improving Website Performance

Today I wondered how my newly purchased Virtual Server performs under load. I am currently using lighttpd as a webserver and MySQL as the database for WordPress. I already knew that MySQL features the Query Cache, which stores the result of issued queries in memory (Oracle’s equivalent of this would be the Result Cache in Oracle 11g). I wondered how much this feature could improve performance on a normal WordPress blog.

I quickly wrote a small Java program to query my website (source code available here: and retrieve the performance metrics from the HTML source code. I then ran it 500 times to get my metrics without the Query Cache turned on. Average time for building the website: 0.115 seconds.

Read the rest of this entry

WordPress MySQL Permissions

Having security in mind, I had some concerns granting all privileges to the WordPress MySQL user (see the instructions from WordPress):

GRANT ALL PRIVILEGES ON databasename.* TO "wordpressusername" [..]

After all, with these privileges the WordPress user would be able to access other databases on this server and do whatever he likes. WordPress has become very popular and is a known target for exploits and the like (as a quick search on will confirm). I didn’t like that idea.

So here is what I did:


This works fine so far and I don’t think my WordPress installation needs more privileges. Note that the ALTER and DROP statements are missing from my list, which could interfere with future updates. But we’ll see…

Hello world

My name is Simon Krenger, I am a Technical Account Manager (TAM) at Red Hat. I advise our customers in using Kubernetes, Containers, Linux and Open Source.


  1. GitHub
  2. LinkedIn
  3. GitLab