Linux

Why doesn't it look different? 14
Here’s the scenario: you’ve set up Dynamically Allocated Storage for the hard drive on your Guest VM in VirtualBox and you’ve run out of space — even though your Actual Size is smaller than the Virtual Size (this happened to me recently when my Virtual Size was 10 GB, and […]

Resize a Fedora, CentOS, or Windows Dynamic Guest Virtual Disk ...

This entry was posted in Linux Reference Technology Windows and tagged CentOS dynamically allocated Fedora LVM partition resize resize VDI VDI virtual disk VirtualBox Windows on by (updated 2816 days ago)
Linux Uptime 6
CentOS 7 was released recently, and so I fired up my build VM so I could attempt to build the OpenDKIM package for submission to EPEL. But the compile barfs on strlcat/strlcopy, because RHEL/CentOS doesn’t have libbsd available (yet?). The libbsd package was a requirement for the package to work […]

Rant: Why is there no libbsd for CentOS 7?

This entry was posted in Linux Rants and Raves Technology and tagged CentOS CentOS 7 compile libbsd OpenDKIM package yum on by (updated 3775 days ago)
Rasmus Lerdorf's opcache-status script 2
When I upgraded to PHP 5.5, I also said goodbye to my beloved APC cache (which never let me down) in favor of Zend OPcache, because it’s already part of the PHP package. Back when I used APC, one of my favorite tools was the apc.php script that showed cache status and allowed me […]

My Favorite Zend OPcache Status Scripts

This entry was posted in Linux Reference Technology and tagged APC apc.php cache memcache memcached OPcache opcode cache php cache script user data cache Zend on by (updated 3676 days ago)
1
If you’re trying to set up an Apache web server on CentOS  as your origin server for Google PageSpeed service, you need to take certain steps to make sure that Apache can see (and also log) the IP address of the visiting host. Otherwise, all you’ll see in your Apache log files […]

Configuring Apache on CentOS 6 for Google PageSpeed Service

This entry was posted in Linux Reference Technology and tagged Apache CentOS configure Google mod_remoteip PageSpeed PageSpeed Service PSS wrong IP on by (updated 3800 days ago)
2
It all started about a week ago. I got an alert email from a server, complaining about a RAID array. That’s nothing terribly out of the ordinary, as I have all of my systems set to alert me if something seems out of place. However, the problem in this case […]

Rant: Google Apps’ Gmail Can’t Protect Me from Misconfigured Mailers

This entry was posted in Linux Rants and Raves Technology and tagged blocked senders Google Apps SPF split domain routing spoof on by (updated 3800 days ago)
Linux Uptime 1
After upgrading from Nagios 4.0 to 4.0.1, I attempted to manually reschedule a check of all services on a particular host, I received the following error: Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update! The source of the problem turned out to be a permissions issue with the nagios.cmd […]

How to Fix Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ ...

This entry was posted in Linux Reference Technology and tagged error Linux nagios nagios.cmd permissions on by (updated 4032 days ago)
Cisco/Linksys E4200 overclocked to 532 MHz 31
It’s a question asked in the DD-WRT forums all the time. It’s a question often asked in the comments of my DD-WRT posts. And it’s a question to which no “official” answer from the primary maintainers of DD-WRT exists… and therefore it will probably keep getting asked. However, based on […]

Difference between DD-WRT BrainSlayer, Eko, Fractal, and Kong Builds

This entry was posted in Linux Technology and tagged BrainSlayer build builds DD-WRT difference Eko Fractal Kong router database SP1 SP2 version on by (updated 3658 days ago)
14
In an effort to extend my WiFi coverage outside our vacation home on a lake, I purchased a Ubiquiti NanoStation LOCO M5. My goal was to provide a strong WiFi signal a few hundred feet into the back yard, onto the beach, and all the way out to the dock. […]

Connecting iOS devices (iPhone, iPad, iPod) to Ubiquiti NanoStation M5 ...

This entry was posted in iPhone Linux Reference Technology and tagged 20MHz 5Ghz Apple channel channel width compatible configuration DFS frequency iOS iPad iPhone iPod LOCO NanoStation NanoStation M5 NSM5 settings troubleshoot Uqibuiti WiFi on by (updated 3433 days ago)
Timeline for Shutdown and Turn Off for the PCNS server OS and the UPS 14
I decided to write this blog post after attempting to configure APC’s PowerChute Network Shutdown (PCNS) software to gracefully shut down a number of Windows and Linux computers on my network, all of which are attached to various APC SmartUPS Uninterruptible Power Supply (UPS) units with AP9617 and AP9630 Network Management Cards […]

HowTo: Configure Low Battery Duration and PCNS to Shut Down ...

This entry was posted in Linux Reference Technology Windows and tagged APC Event Shutdown Delay graceful shutdown Low Battery Duration Maximum Required Delay NMC PCNS PowerChute Network Shutdown shutdown Shutdown Delay UPS on by (updated 3601 days ago)
Postfix 2.9 Upgrade 5
I run a number of “real” Postfix servers that live “away from home,” in a cozy server cabinet at our colo facility, but I also like to keep a Postfix server handy in the basement, running on an ancient (but rock solid) Dell PowerEdge 2450 running CentOS 5. I don’t […]

HowTo: Get Around Comcast Port 25 Block with a Postfix ...

This entry was posted in Linux Reference Technology and tagged block blocked Comcast howto port 25 Postfix relay workaround on by (updated 3990 days ago)
Linux Uptime
This is one of those reference posts mainly for myself, that helps me remember commands for stuff I have to do from time to time, but not often enough that I remember it without searching for it. This post is about MySQL commands. Resetting the Root Password: http://dev.mysql.com/doc/refman/5.0/en/resetting-permissions.html What to run […]

MySQL Commands: Password Reset, Initial Setup, and more!

This entry was posted in Linux Reference Technology and tagged MySQL password reset startup on by (updated 4212 days ago)
Cisco/Linksys E4200 overclocked to 532 MHz 42
UPDATE: Newer versions of the DD-WRT firmware now include a web-based option for selecting your overclock speed, if it’s supported on your device. You can still follow these steps to overclock (and I recommend you continue reading so you understand what you’re doing), but now you can access overlocking on the Administration/Management tab. […]

How To: Overclock a Cisco/Linksys E4200 Router running DD-WRT

This entry was posted in DIY Linux Reference Technology and tagged 532 MHz clock speed DD-WRT E4200 Linksys overclock overclocking on by (updated 3539 days ago)
2
When setting up a vanilla WordPress installation on a vanilla CentOS server with a vanilla Apache install, I kept getting 404 errors on pages and posts when Permalinks was set to anything other than the default. I fixed it by editing Apache’s httpd.conf file to add the following in the […]

WordPress File Not Found with Custom Permalinks

This entry was posted in Linux Technology and tagged 404 AllowOverride Apache File Not Found Permalink VirtualHost WordPress on by (updated 4147 days ago)
Upgrade from Fedora 17 to 18 with FedUp 1
Fedora 18 (codename Spherical Cow) was officially released today, and there’s a mad scramble to figure out how to upgrade to this latest Linux desktop from Fedora 17. Previously, you’d have to either do a fresh install with a CD or DVD, or you could use the built-in PreUpgrade method. […]

Upgrade from Fedora 17 to Fedora 18 with FedUp

This entry was posted in Linux Reference Technology and tagged Fedora Fedora 17 Fedora 17 to 18 Fedora 18 fedora upgrade 17 to 18 fedup FedUp Install Linux PreUpgrade update Upgrade on by (updated 4324 days ago)
WiFi connection on iPhone 4 680
UPDATED Dec 21, 2016. This post is a reference post for those looking to squeeze maximum speed out of their Cisco Linksys E4200 v1 wireless router running DD-WRT. The DD-WRT build I currently recommend for this router is K2.6 30880 (by BrainSlayer). IMPORTANT: My testing shows that DD-WRT K2.6 builds are much faster on the […]

My Cisco Linksys E4200 DD-WRT Settings for Max Speed

This entry was posted in DIY iPhone Linux Reference Technology and tagged 22000M big BrainSlayer configuration DD-WRT ddwrt E4200 fiber Fractal Heartbleed Kong Linksys mega nas OpenSSL OpenVPN optimize settings speed std TCP Congestion Control Transmit Power usb WiFi WiFi speed wireless wireless speed on by (updated 2889 days ago)
Setting up multiple WLANs in DD-WRT 14
Even for the extremely ungeeky, having WiFi available throughout your house is pretty much standard these days. And while the next logical step of securing that network via encryption (WEP is for n00bs — those in the know use WPA2-AES) may not be standard, it really should be. Assuming you do […]

Use DD-WRT to Create a Guest WiFi Network and Block ...

This entry was posted in Linux Technology and tagged block br1 bridge DD-WRT firewall guest network iptables Linux Skype WiFi on by (updated 3564 days ago)
Remote Cable Modem and Router Power Cycle 2
We’ve all been there. You try to load a web page, or check your email, or download a file, and nothing happens. “The Internet’s down!” is the cry at my house when we lose connection. It’s also the #1 reason why people call their Internet service providers’ tech support numbers, […]

How To Automatically Power Cycle Your Modem and Router on ...

This entry was posted in Home Theater & Automation Linux Technology and tagged automate Comcast Linux modem PHP power cycle reboot router script on by (updated 3564 days ago)
Postfix 2.9 Upgrade 6
I’ve previously written a how-to for compiling Postfix from source on a CentOS 5 box. I recently tried following the same steps on a CentOS 6 box, to upgrade from Postfix 2.6.6 which is installed by default. I’m glad to report that the same instructions will work just fine to upgrade […]

Building Postfix 2.10 on RHEL6 / CentOS 6 from Source

This entry was posted in Linux Reference Technology and tagged binaries build CentOS CentOS 6 compile Postfix Postfix 2.6.6 Postfix 2.9 Redhat RHEL RHEL 6 rpm source on by (updated 4298 days ago)
Yahoo and Postfix 26
If you’re getting “temporarily deferred” Postfix log entries when trying to send mail to Yahoo! that look like this: host mta7.am0.yahoodns.net[66.196.118.34] refused to talk to me: 421 4.7.0 [GL01] Message from (xxx.xx.xx.xxx) temporarily deferred - 4.16.50. Please refer to http://postmaster.yahoo.com/errors/postmaster-21.html or status=deferred (host mta7.am0.yahoodns.net[66.196.118.35] said: 451 mta1336.mail.bf1.yahoo.com Resources temporarily unavailable. […]

How-To: Postfix configuration to reduce Yahoo temporary deferrals using Transport ...

This entry was posted in Linux Reference Technology and tagged 420 421 deferral GL01 Postfix refused to talk to me Resources unavailable temporarily status=deferred temporarily deferred Yahoo Yahoo Mail yahoo temporarily deferred on by (updated 3800 days ago)
8
I often say there are only two types of data: data that is backed up, and data that is waiting to be lost. Even if you’re the most contentious hax0r who always backs up your data, if your backups are stored in the same physical location as the source data, […]

How to Back Up a Linux Server to Amazon S3 ...

This entry was posted in Linux Reference Technology and tagged Amazon Amazon backup Amazon S3 AutoMYSQLBackup backup backup to s3 CentOS Duplicity Fedora Linux off-site RHEL S3 s3 backup server on by (updated 4470 days ago)
17
One recommended way to help secure your Postfix mail server is enabling TLS (Transport Layer Security) for connections to and from Postfix. You can search for more detailed descriptions of exactly how TLS works, but basically it’s a crypotgraphic protocol that allows connections between systems to remain secure. It relies on a key […]

Configure Postfix TLS with a Free StartSSL Certificate

This entry was posted in Linux Reference Technology and tagged certificate csr free key Postfix self-signed SSL StartSSL TLS on by (updated 3414 days ago)