FarmSoft Studios Scratchpad » networking

Plesk Backup Error: ‘ERROR Unable to open /opt/psa/var/apspkgarc/archive-index.xml’

FarmSoft Studios — Wed, 22 Apr 2009 15:03:31 +0000

I was getting the following error when trying to use Plesk’s backup function:

ERROR Unable to open /opt/psa/var/apspkgarc/archive-index.xml

The solution is to visit the “Application Vault” under the “Server” tab of your Plesk interface. The file gets auto-generated at that point.

For more information on how to use Plesk’s backup feature, read this post

Flushing your DNS cache in Mac OS X 10.5.x Leopard

FarmSoft Studios — Tue, 06 Jan 2009 19:19:12 +0000

Simply run

dscacheutil -flushcache

in the Terminal. (/Applications/Utilities/Terminal.app)

If you are running a version of Mac older than Leopard, such as 10.3 Panther, or 10.4 Tiger, the command is a little different:

lookupd -flushcache

Collaborative Real-Time Editing

FarmSoft Studios — Mon, 22 Dec 2008 21:14:29 +0000

EtherPad is a collaborative, real-time text editor created by the originators of AppJet. An EtherPad document is quickly set up without any need for registration. By sharing the URL of the document that you created, others who visit that page will be able to see, in real-time, whatever you’re typing. This is awesome for collaborating on that script, or piece of code that you want your super-duper developer friend to help you on. Currently they have syntax highlighting for JavaScript, but I am assuming that they will begin supporting more languages in the near future. Head on over there and check them out!

Installing ntop on Mac OS X 10.5.x, Leopard

FarmSoft Studios — Fri, 19 Dec 2008 16:39:45 +0000

First off, install MacPorts, with some additional instructions here.

Then open up the Terminal (/Applications/Utilities/Terminal.app) and type:

sudo port install ntop

Notice: It will take a LONG time even on good hardware (about 10 minutes on my Mac Pro with a striped RAID boot array).

After that is complete, you can then launch it by running:

sudo ntop -d

which launches it in daemon mode so that you can close your terminal and still have it running in the background.

It should prompt you to enter the admin password, which has to be 5 characters or more. Type it again to confirm, and it should launch.

Notice that if you do not run it with sudo, you may receive this message:

mac-pro:~ ryebread$ ntop
Fri Dec 19 10:57:15 2008  NOTE: Interface merge enabled by default
Fri Dec 19 10:57:15 2008  Initializing gdbm databases
Fri Dec 19 10:57:15 2008  **ERROR** ....open of /opt/local/var/ntop/prefsCache.db failed: File open error
Fri Dec 19 10:57:15 2008  Possible solution: please use '-P '
Fri Dec 19 10:57:15 2008  **FATAL_ERROR** GDBM open failed, ntop shutting down...
Fri Dec 19 10:57:15 2008  CLEANUP[t2687149856]: ntop caught signal 2 [state=2]
Fri Dec 19 10:57:15 2008  ntop is now quitting...

It’s just telling you that it does not have the proper permissions to run in the /opt/local/var/ntop/prefsCache.db database.

Go to a web browser, and type:

http://localhost:3000

and you should be able to see an interface something like the following:

ntop running on Mac OS X 10.5.6, Leopard

Mounting a Samba (SMB) Share in CentOS

FarmSoft Studios — Fri, 10 Oct 2008 19:45:00 +0000

Need to mount a samba share on your CentOS server from the command line?

Create a directory on the root:

mkdir /sharename

Then mount the share:

mount -t cifs /// /sharename

if you type df -h you should see that your share is now mounted on the mountpoint that you created earlier.

Connecting to the Remote Windows Console with Mac’s RDP Client

FarmSoft Studios — Fri, 03 Oct 2008 16:41:52 +0000

Ever needed to connect to the remote console of the machine rather than running through a terminal services session so that you could install certain software, or reset stuck terminal services sessions from a remote location? All you have to do is type /console behind the host in the window.

Blocking a certain IP address with iptables

FarmSoft Studios — Wed, 20 Aug 2008 14:50:02 +0000

To block an ip address from accessing your linux box, you can use the following iptables rule:

iptables -A INPUT -s 222.124.24.131 -j DROP

If you just need to block a certain port (i.e. port 22 for SSH), you would do it like so:

iptables -A INPUT -s 222.124.24.131 -p tcp --destination-port 22 -j DROP