This is a summary of standard and nested RAID levels that I might implement either in a small home/office environment or from enterprise vendors. I’m avoiding the rarely-seen levels like 2, 3, and 4 as well as vendor-specific “RAID” implementations like RAID-S or X-RAID. Fortunately, many major vendors like Dell, Supermicro, and Silicon Mechanics are […]
Here’s an easy one: you want to customize the Drupal search form provided by the Search module in your Drupal 7 site. Fortunately, Drupal provides an easy way to do this, via hook_form_alter(). Put something like this in your theme’s template.php: This defines the appearance of the search block form, which you can then place […]
On my Drupal 7 site here, I wanted to create a method of automatically injecting my Google Ad banners on all content pages before the Disqus comments thread. You could do this manually, say by adding a text field to your basic page content_type with a default value of all the Google Ads JavaScript, but […]
tcpdump is a useful packet analyzer distributed under the BSD license. It is included with most Linux and Unix distros, and it’s available for Windows using the Winpcap library. As you might imagine, tcpdump is excellent at troubleshooting problematic connections to remote systems where the cause is otherwise unclear. This is particularly useful for getting […]
sed and awk are two powerful but often overlooked data processing tools, and if you know how to use them effectively you’ll be well ahead of many sysadmins and developers. sed sed is an in-place stream editor, that is, it accepts input from a file or STDIN, manipulates the data stream in some way, and […]
grep is a useful utility that finds fixed strings or patterns of text in a given file or standard input. Used in conjunction with error logs or debugger output, grep can help a programmer identify errors in an application code base or filesystem; to help with this, grep understands regular expressions, what it calls “extended” […]
LOC records allow WGS84 location to be published via the Domain Name Service. They are defined in RFC 1876. If a host has a LOC record, it can be looked up via dig -t loc: LOC records are expressed in terms of Degrees-Minutes-Seconds, not decimal latitude and longitude. You can convert them using a tool […]
Recently I was testing some web servers with the SSL Labs SSL web server test. This article describes the fixes I applied to Ubuntu Server 12.04 to get an A+ on the test. The SSL Labs Test Auditing the SSL certificates on your web server occasionally is a good idea, since you always want to […]
So you don’t know your MySQL root password but you do have the root password of the server. Here’s a quick way to reset your MySQL root password on the command line: 1. Stop MySQL $ service mysql stop 2. Start MySQL in safe mode without a password $ mysqld_safe –skip-grant-tables & 3. Log into […]
Update 2015: Support and development of TrueCrypt have, of course, now ended, although an independent audit of TrueCrypt revealed no severe security problems. I’d suggest the TrueCrypt fork VeraCrypt as a replacement. Note: I’m using Fedora 19 here. Results will vary on different versions. If you’re trying to run the TrueCrypt virtual disk encryption software […]