Articles in the system_administration category

1. rsync: on remote machine: --extended-attributes: unknown option

   Posted on May 27, 2011 in System Administration

   rsync: on remote machine: --extended-attributes: unknown option
   

   If this is the output you get when running rsync, you are almost certainly running the Mac OS X version of rsync -E on the client with something else on the server side. The fix is to install the MacPorts version of rsync …

2. ab Results Before and After Server Move

   Posted on May 25, 2011 in System Administration

   

   Behold, the benefits of virtualization!

   I spent most of the evening preparing to move a few websites. I decided to do some benchmarking just to see what sort of improvement I was getting from the new server setup. Although the old server didn't feel slow when browsing sites, the results …

3. Ubuntu: Installing VMware Tools in 10.04 LTS

   Posted on May 23, 2011 in System Administration

   Although this process is well documented on the Ubuntu community site, I decided to take notes of the exact steps that I took so that I wouldn't have to fumble through that long document next time. I'm installing the tools in a clean install of Ubuntu 10.04.2 LTS …

4. How Big is the World of Cloud Computing?

   Posted on May 02, 2011 in System Administration

   

   Via: Wikibon

5. Adding Windows Shared Printers to Mac OS X 10.6 (Snow Leopard)

   Posted on March 29, 2011 in System Administration

   I was recently struggling to add a Windows shared printer to my MacBook Pro (running Mac OS X 10.6 (Snow Leopard)) until I ran across this post which gave me two important hints:

   1. You need to use the Advanced tab in the Add Printer dialog. You can find this …

6. Adding Devices to Cacti in Bulk

   Posted on March 25, 2011 in System Administration

   I recently had to add over 100 new devices into Cacti. Believe it or not, you can do this in bulk using the command-line tools provided with Cacti. I used to add_device.php, add_tree.php, and add_graphs.php scripts to get the job done.

   First, I created a file (/tmp …

7. Clear Windows DNS Server Cache From the CLI

   Posted on February 22, 2011 in System Administration

   Clearing the Windows DNS Server cache from the command line is an easy task.

   C:\> dnscmd . /clearcache
   

   The . indicates the local DNS server. You can use this command to clear the cache of remote DNS servers by replacing the . with the hostname or IP address of the remote server.

8. RHEL 6 Brings Virtualization Changes

   Posted on November 12, 2010 in System Administration

   Yesterday, Red Hat announced the release of Red Hat Enterprise Linux (RHEL) 6. For those of us interested in virtualization, RHEL brings along many changes.

   Performance

   RHEL 6 promises enhanced virtualization performance in several ways. First, the operating system is now theoretically able to handle 4,096 CPUs, 16 TB …

9. MySQL + SELinux: Can't change dir (Errcode: 13)

   Posted on October 21, 2010 in System Administration

   If you're using a non-standard MySQL data directory on your Red Hat Enterprise Linux (RHEL) server, you may have seen an error like /usr/libexec/mysqld: Can't change dir to '/mysql_data/' (Errcode: 13). The key to fixing this problem is to ensure the new MySQL data directory has the proper …

10. Cisco Access Registrar: Automatically Clear Old Sessions

    Posted on September 02, 2010 in System Administration

    While doing some testing with Cisco Access Registrar (CAR) 5.0, I noticed that the test user had hundreds of old sessions hanging around:

    --> query-sessions /r with-User X
    Sessions with-User X for /Radius
      Sessions for /Radius/SessionManagers/session-mgr-1:
        S432 Key: 04000000000CF660, NAS: NAS.slaptijack.com, NAS-Port: 0, User-Name: X, Time …