Sometimes, it may seem convenient to quickly connect a Bluetooth keyboard and a Bluetooth mouse to a Mac OS X Server machine for administration. The not so intuitive consequence of this however is, that at future startups, if there’s no keyboard or mouse connected to the machine (which is the common case with servers), Mac OS X will by default fall back to searching for that once connected Bluetooth keyboard or mouse and even stops booting when it doesn’t find them.
In order to prevent this, do the following on your Mac OS X Server:
- Open Bluetooth Preferences
- Disconnect and remove any associated Bluetooth devices
- Click the “Advanced…” button
- In the advanced Bluetooth settings, deselect both “Open Bluetooth Setup Assistant at startup if no keyboard is detected” and “Open Bluetooth Setup Assistant at startup if no mouse or trackpad is detected”
- Unless really needed, disable Bluetooth on a server. So, better grab a USB keyboard and mouse next time you need to do some admin ;)
When using Mac OS X, I used to use the CLI vim by the excellent Homebrew package manager.
Now I’ve just stumbled over macvim, which is kind of a “deluxe vim” for Mac OS X, including adjusted key bindings for the Mac and a GUI menu, supporting Cocoa file dialogs, among others.
It’s highly recommended if you want to have the best of both the CLI and GUI editor worlds.
Running the console IRC client weechat (not to confuse with the wechat messenger) in a screen or tmux session on a Linux (or Mac OS X) server and accessing it trough mosh is a great way to use IRC on the go, i.e. with a unsteady Internet connection.
P.S. Thanks to Devaux and rmeyer for the hints
If you ever need to quickly test an FTPS server, the CLI ftp client http://lftp.yar.ru is quite handy.
After upgrading Debian, OpenDKIM sometimes stops running or fails to properly restart. If you don’t actively monitor your ZCS server, the only way to detect this is either through a growing mail queue of unsent messages or through a note in the ZCS server admin panel.
Usually, manually restarting either OpenDKIM itself or the whole ZCS server once “fixes” the problem:
# service zimbra restart
# /etc/init.d/zimbra restart
In other cases, fixing the permissions may help:
# /opt/zimbra/libexec/zmfixperms -verbose -extended
Mac OS X comes with a pretty useful tool to list all the details about your system:
E.g. to find out whether your RAM supports ECC:
# system_profiler|grep ECC
Or wether your SSD supports TRIM:
# system_profiler|grep TRIM
TRIM Support: Yes
A friend recently told the following joke:
“The idea that git can be used offline is an illusion – you still need connectivity for googling which arguments to pass to what command.”
That’s an exaggeration, of course, but as always, there’s a grain of truth in it. So here we go:
Here’s a quick overview how to migrate a ZCS mail server (based on Ubuntu) to a new IP address:
0) Not covered here: Adjusting DNS entries. Make sure you lower the TTLs of the relevant DNS entries a couple of days in advance in order to minimize downtime for clients (e.g. set a TTL of 300 for a 5 minute downtime).
1) Set the new IP address in:
* The relevant DNS entries
* If ZCS runs in a container/VM, don’t forget to adjust its IP address too.
2) If the new IP address is part of a new subnet, make sure to add this new subnet to ZCS’s trusted_networks, otherwise, sending (relaying) messages through ZCS from Zimbra Desktop (or any other mail client) won’t work. This can be set using ZCS’s web admin interface (i.e. https://mail.myserver.com:7071/zimbraAdmin/):
Navigate to “Server settings”, then open the “MTA” tab and set something analogous to the following in “MTA Trusted Networks”:
3) Restart networking and the ZCS services (it’s important, as this adjusts the trusted_network setting in ZCS’s amavisd too):
# /etc/init.d/zimbra stop
# /etc/init.d/networking restart
# /etc/init.d/zimbra start
Alternatively, just reboot the server, particularly if it runs in a VM.
Note: The need for the adjustments in step 2) might come as a surprise. Authenticated messages to be relayed through ZCS apparently seem to originate from the external IP address, not localhost/127.0.0.1.
 A typical postfix error message might look like:
Delivery Failure Notification: Invalid address: somebody . com.zimbra.cs.mailbox.MailSender$SafeSendFailedException: MESSAGE_NOT_DELIVERED; chained exception is: com.zimbra.cs.mailclient.smtp.InvalidRecipientException: RCPT failed: Invalid recipient email@example.com: 554 5.7.1 : Relay access denied
iTerm2, the successor of iTerm, seems to be quite a bit better then the default Mac OS X terminal app:
iTerm2 – Mac OS Terminal Replacement.
If only every Mac OS X app (i.e. Quartz) would also support copy on select, middle button paste and the other X11-like features!  Further, I’d love to see a terminal app that disallows pasting (cmd-v) from the keyboard-controlled clipboard completely as this is potentially a very dangerous thing.
 Note: It’s possible to emulate X11’s behaviour to some degree using BetterTouchTool. It’s still not the same though as X11 distinguishes between the mouse-controlled buffer and the keyboard-controlled buffer and doesn’t just “paste from the clipboard”. For reference, see: