Wednesday, September 30, 2015

Create OS X 10.11 El Capitan Bootable Installer (Simplest Way)

Simplest way to create install media for OS X 10.11 El Capitan (successfully executed this from OS X 10.10.5 Terminal)

1) Make sure "Install OS X El Capitan.app" is in your Applications folder (it can be downloaded here)

2) Format destination volume and name "Untitled" (must be Mac OS Extended (Journaled), GUID Partition Table)

3) Run in Terminal:

sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath "/Applications/Install OS X El Capitan.app" —-nointeraction

Monday, January 26, 2009

SMTP Authentication, Port 587, and OSX Server 10.4.11

I was having trouble getting clients to authenticate to one of my servers (running Mac OSX 10.4.11 Server) so they could use it for SMTP. This was much needed, especially for those who’s ISPs blocked port 25, and for those who travel. There were dozens of suggestions out there, some helpful, some not.


After reading, breaking and fixing mail, and trying all the suggestions in posts I could find, this is what did it to get it to work. Now clients can configure their email programs to use my SMTP server, port 587, using authentication. It’s easy as 1, 2, 3.


1) In /etc/postfix/master.cf uncomment the line:


submission inet n - n - - smtpd


This will allow SMTP over port 587, the "submission" port.


In /etc/postfix/main.cf modify the line:


smtpd_client_restrictions =


and make sure “permit_sasl_authenticated” is in there. It should look something like this:


smtpd_client_restrictions = permit_sasl_authenticated permit_mynetworks reject_rbl_client zen.spamhaus.org permit


This line is modified by Server Admin’s “Use these junk mail rejection servers (real-time blacklist):” field so keep an eye on it if you change something in Server Admin.


3) sudo postfix reload


Obviously port 587 should be opened in the firewall, and at least one authentication method should be selected in Server Admin. I recommend selecting only one secure method to require authentication of that type (eg. CRAM-MD5 or Kerberos.)


Apple’s documentation is not so thorough (no need for them to rewrite comprehensive documentation of open source software.) But you can find more detailed explanations at http://www.postfix.org. Postfix configuration parameters http://www.postfix.org/postconf.5.html.


WARNING: Keep in mind that this adds an increased security risk, as does opening any additional port or adding any additional service. I'm assuming you know what you're doing and know how to avoid setting your server up as an open relay.


As soon as the spam people find out about your port 587 being open they will most likely (and relentlessly) try to gain authentication and, at the very least, increase traffic to your network. If your server is used to relay spam you could end up on a blacklist, have a bunch of people mad at you, or even be sued. Vulnerable mail relays are bad. You can test for an open relay here: http://www.abuse.net/relay.html

Wednesday, March 8, 2006

Narcoleptic PowerBook G4 Solution

Many people who own a PowerBook G4 have been experiencing a well documented problem called the Narcoleptic PowerBook aka NAP. These machines are spontaneously going to sleep due to a faulty temperature sensor under the trackpad sending an erroneous overheating message to the computer, causing it to go into emergency sleep.


The log files on these machines confirm that it is, in fact, an overtemp signal causing the machine to go to sleep, and running a monitoring program such as Temperature Monitor will graphically display the culprit.


Apple has not initiated a recall for these machines but offers a logic board/top case replacement as a solution for a fee. Some people claim to have fixed the problem by modifying the kernel extension of the operating system, but this is surely a temporary solution that a simple software update could undo.


There is another way... Remove the faulty temperature sensor.


How does it work? How do I know this problem relates to me?


First, look at your system log file. (Open "Console" which is located in Applications/Utilities.) By default, you should be looking at system.log. If not, open the logs list and select system.log. If you see a line there that looks similar to:


Sep 25 03:18:43 your-name-powerbook-g4-15 kernel[0]: Power Management received emergency overtemp signal. Going to sleep.


Then the next step would be to download and run Temperature Monitor. You will see all the available sensors and will notice a dramatic and sudden fluctuation in the "Trackpad" sensor. That's it. That's what's been making your PowerBook go to sleep.


Once you've verified that the trackpad sensor is in fact the problem you can remove it. If you're not comfortable disassembling your laptop yourself Macintosh Guru offers this "faulty temperature sensor removal" service for $145.00.


Don't I need this sensor? Don't you need your tonsils, appendix, and wisdom teeth? Well, maybe. But if they become problematic, they're removed.