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Wednesday, February 19, 2014

Detect a New Disk and Grow a Filesystem in Linux without Rebooting

If you have ever wanted to add a new hard disk to a Linux VMware guest without rebooting here is the solution. After running this command you should be able to use the new disk as you please. This is really useful for growing an LVM filesystem on the fly.
Run this command after adding the new disk to you VMware configuration. This will allow your Linux guest to detect the new disk and assign it as a device.
ls /sys/class/scsi_host/ | while read host ; do echo "- - -" > /sys/class/scsi_host/$host/scan ; done
Once you have ran this command you can grow the LVM filesystem as usual. (Where X is the new device added.)
# Create a new partition on the new disk. Assign it the type of Linux LVM, 8e.
fdisk /dev/sdX

# Create the new physical volume.
pvcreate /dev/sdX1

# Extend the volume group of your choice.
vgextend /dev/VolumeGroupName /dev/sdX1

# Confirm the new physical extents are available and take note of the number.
vgdisplay

# Extend a logical volume where 1234 is the number of PEs you would like to add.
lvextend -l +1234 /dev/VolumeGroupName/LogVolName

# Resize the EXT filesystem.
resize2fs /dev/VolumeGroupName/LogVolName

# Confirm the new space is available.
df -h
Once complete you should have extra space on your Linux guest.

Sunday, February 16, 2014

Recursive Directory/File Permissions

I’m constantly needing to recursively set different permissions on files and directories to make suPHP happy. I’m posting this here for easy reference.
# Directories
find . -type d -exec chmod 755 {} +

# Files
find . -type f -exec chmod 644 {} +

Friday, August 3, 2012

Why I Chose Unraid for my Home Storage Solution

Unraid

Description

Unraid is a Slackware Linux based operating system that provides an easy way to create network attached redundant storage. It's best suited for archival purposes. It allows for the loss of one disk without losing data.

Unraid has three different licenses you can use, Basic (free), Plus ($69), and Pro ($119). Look at the license page for a description on how they differ.

Advantages

  • Runs off of a USB flash drive. You don't lose a SATA port or disk for the operating system.
  • Mix and match hard drives and sizes. You can put drives of any size in the array. You only lose the largest disk in the array for parity. (Similar to a Drobo)
  • Web interface. A simple web interface lets you configure everything.
  • Supports various protocols including SMB, AFP, and NFS.
  • No vendor lock-in. Although you're using the proprietary Unraid system, all data is stored on the disks in the ReiserFS filesystem
  • Since it's using ReiserFS, if you lose more than one disk at a time you'll be able to get data off the rest of the disks in the broken array.
  • Use your own hardware. I built a little server with an Atom processor for less than the price of the cheapest Drobo.
  • Set it and forget it. I've had my system running for almost two years
  • Stable. I set mine up and have basically forgotten about it. It just works and has been since May 2011 when I configured it.
  • Spins down drives when not in use, unlike RAID-5.
  • Support and community. There's a very active forum and wiki to help you with any issues, add additional functionality, and much more.

Disadvantages

  • Price could be. I purchased the $70 license. If you only have 3 disks and don't require some of the extra features, there is a free version.
  • Write speeds. If you have the need to push stuff to the server at more than 30MB/sec, this may not be the best choice. If you're just archiving stuff, it really is not an issue. You can also speed the writes up with a cache drive.

Why I Chose Unraid

Throughout my history of having redundant storage at home I've had two previous setups that really failed me.

Linux Software RAID-5

Linux software RAID is great, but I had two drives fail at once. I lost everything. With Unraid I would've been able to recover some of the data on the drives that had not failed. You also cannot mix and match drive sizes and the disks never spin down.

Drobo

I had the second generation Firewire 800 Drobo. Transfer speeds were horrible. It still needed a computer running to serve data. I accidentally plugged the wrong power supply into it and it stopped working. I was now stuck buying another expensive Drobo to get my data or coming up with another solution. That is when I found Unraid.

The Drobo is actually a really nice device. The newer ones are supposed to be a lot faster and some even have sharing capabilities. It's just too expensive and they've got you with vendor lock-in.

Links

If I haven't sold it to you yet, here's a few links to learn more about Unraid.

Wednesday, August 1, 2012

MySQL: Change Collation on an Existing Table

I recently ran across an issue where a table's collation was set to latin1_swedish_ci and it really should have been utf8_unicode_ci. Just changing the collation didn't seem to be doing the trick because some characters were still messed up. That's when I realized you need to convert the current character set to UTF8. After doing this everything worked as expected.

ALTER TABLE table_name CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci

Wednesday, August 24, 2011

Configure PhpStorm to Auto-complete CakePHP Models, Views, and Controllers

After playing around a bit today I finally figured out how to get PhpStorm to auto-complete methods for models and controllers. Here's what you need to do.

Removing Multiple Definitions


First, let's tackle the multiple definitions problem that we see below.

Multiple Definitions


There are multiple places defining AppController. We need to remove the ones that are included in the following locations from our 'Directories' in the project's settings.

The two locations are:
  • $CAKEHOME/cake/console
  • $CAKEHOME/cake/tests
Exclude Directories


Next we need to mark the following file as plain text.
  • $CAKEHOME/cake/libs/controllers/app_controller.php
Mark as Plain Text


You should now see that PhpStorm is no longer complaining about multiple definitions. If it is you may want to check your plugins/components to see if they're mucking it up. If they are, just mark the file with the definition as plain text.

Multiple Definitions Resolved


Auto-completion should now work for the controller. However, it's still not working correctly on our model.

Autocomplete works, but not on the model.


Adding the Model


To fix the model we need to add a magic property to the class.

 /**  
 *@property ModelName $ModelName  
 */  

Here's an example from the controller we've been working in.

@property ModelName $ModelName


 We can now auto-complete on our models in the controller.

Auto-complete on the model.


Defining Model Relationships


Lastly, we need to add magic properties to our models to define its relationships with other models. Basically, for each "belongs to" relationship defined in the model's file you need to add the magic property comment.

Define belongs to relationships


We can now auto-complete these relationships.

Auto-complete model relationships


Setting Up Helper Auto-completion in Views


To get auto-completion working in views we need to include a file created by junichi11 over at GitHub.

Download this file and save it in a directory somewhere outside of your current project. I did this so I could use the same file on multiple projects.
Now add that directory to your current project.

Open a view file and add the following variable definition.

 /**  
 *@var $this View  
 */  


You should now be able to auto-complete helpers in your view!

Auto-completion of helpers


Core Component Auto-Completion


Add the following to your app_controller.php file and this will add component auto-completion.

 /**  
  * CakePHP Component & Model Code Completion  
  * @author junichi11  
  *  
  * ==============================================  
  * CakePHP Core Components  
  * ==============================================  
  * @property AuthComponent $Auth  
  * @property AclComponent $Acl  
  * @property CookieComponent $Cookie  
  * @property EmailComponent $Email  
  * @property RequestHandlerComponent $RequestHandler  
  * @property SecurityComponent $Security  
  * @property SessionComponent $Session  
  */  

Wednesday, April 21, 2010

SABnzbd URL Bookmarklet (NZBMatrix)

Here's a simple bookmarklet that will take the URL of the current page you're on and tell SABnzbd to download it. It works great if you're using NZBMatrix and on the page for the post you're wanting to download. Perfect for your mobile browser.

javascript:location.href='http://yourhost:8080/api?mode=addurl&name='+encodeURIComponent(location.href)+'&apikey=yourapikey';  

Be sure to insert your SABnzbd API key and hostname (or IP address) into the bookmarklet's code.

Wednesday, January 20, 2010

Perl Find and Replace One Liner

I'm constantly needing a way to easily change a line in a bunch of configuration files. I thought I'd share the way I do it here.

perl -p -i -e 's/oldstring/newstring/g' *

This allows you to use a regular expression and perform the find and replace.