MySQLTuner

I finally made it around to upgrading Wordpress to 2.8.2 and it seems to be working like a charm. It looks like there were some bug fixes and a XSS vulnerability was patched. ©2009 Racker Hacker. All Rights Reserved..

I found a great post on Overstimulate about handling the rotation of rails logs when you use Phusion Passenger. Most of the data for your application should end up in the apache logs, but if your site is highly dynamic, you may end up with a giant production log if you’re not careful. Toss this [...]

Occasionally, I’ll end up with a mailbox full of random data, alerts, or other useless things. If you have SSH access to the server, you can always clear out your mail spool, but if you connect to an IMAP server, you can use mutt to do the same thing. First, use mutt to connect to [...]

The best uses I’ve found for the SIGSTOP and SIGCONT signals are times when a process goes haywire, or when a script spawns too many processes at once. You can issue the signals like this: kill -SIGSTOP [pid] kill -SIGCONT [pid] Wikipedia has great definitions for SIGSTOP: When SIGSTOP is sent to a process, the usual behaviour is to pause [...]

When I tried to do an automatic upgrade from Wordpress 2.7.1 to 2.8 yesterday, it failed miserably. The files were all put in place, but when I tried to load /wp-admin/upgrade.php, this error popped up: Fatal error: Call to undefined method ... [More] wpdb::has_cap() in /path/to/wordpress/wp-admin/includes/schema.php on line 22 I was perplexed at the error, so I restored [...] [Less]

There are two main ways to upgrade Fedora 10 (Cambridge) to Fedora 11 (Leonidas): » What the Fedora developers suggest: # yum -y upgrade # yum -y install preupgrade # yum clean all # preupgrade-cli "Fedora 11 (Leonidas)" Of course, if you’re ... [More] doing this on a Fedora desktop, you can use preupgrade (rather than preupgrade-cli) to upgrade with a GUI. » The [...] [Less]

Sometimes we find ourselves in places where we don’t trust the network that we’re using. I’ve found myself in quite a few situations where I know my data is being encrypted, but I want an additional layer of protection. Luckily, that protection is built into SSH if you’d like to use it. Create a [...]

I found a really helpful tip on Xaprb for comparing result sets in MySQL: mysql> pager md5sum - PAGER set to 'md5sum -' mysql> select * from test; a09bc56ac9aa0cbcc659c3d566c2c7e4 - 4096 rows in set (0.00 sec) It’s a quick way to ... [More] determine if you have two tables that are properly in sync. Although there are better ways to compare [...] [Less]

Servers with hot swappable drive bays are always handy. However, things can turn ugly if the SCSI controller doesn’t like a new drive when it is inserted. You may end up with these errors in your dmesg output: kernel: sdb : READ CAPACITY failed. kernel: sdb : status=0, message=00, host=4, driver=00 kernel: sdb : sense [...]

If you have a centralized syslog server, or you use Splunk for log tracking, you may find the need to get older log files into a syslog port on that server. Luckily, it’s easily done with netcat: cat some.log | nc -w 1 -u yoursyslogserver.com 514 ©2009 Racker Hacker. All Rights Reserved..