Hide a volume

To hide a volume in Mac OS X 10.6 you will need to do the following

First, Install the Developer Tools (You can find these on the Mac OS X Installation Disc that came with your machine, or you can download Xcode from the Mac App Store).

Once you have done this Open a Terminal Window and type the following

sudo SetFile -a V /Volumes/VolumeName

replace VolumeName with the name of the volume you wish to hide

then type

sudo reboot

when the machine has rebooted you will notice that the volume no longer appears either on the desktop, or in a Finder window

to reveal a previously hidden volume just type the same command but use a lower case v

eg.

sudo SetFile -a v /Volumes/VolumeName

A common use for this would be to hide a volume with sensitive data on, although this will not encrypt any data so is not the best method for confidential items.

Change passwords from the command line

If you believe that your admin password has been compromised then it is always a good idea to change it, the dilemma is, if you have the same password for hundreds of machines, then it will be quite a hassle to go round to them all and change it, so you have 2 options

1. Invest in Apple Remote Desktop (ARD) to manage your machines.
2. SSH into all machines and change them that way.

I have ARD, so I will guide you through using that, the solution is in essence the same for either option, it’s just a hell of a lot quicker with ARD.

First, you need to select all the machines you wish to make the amendment on, then, you need to select the Send Unix Task option, you will want to run this as root, so select that option, then type the following into the command window

dscl . -passwd /Users/USERNAME PASSWORD

change USERNAME for the short name of the account you wish to change the password of, and swap PASSWORD for the new password, if you don’t set a new password then it will blank the password and then you will need to set a new one the next time you log in

One downside to this timesaving tip is that the next time you log in to the machines, you will need to have knowledge of the old password, so you can unlock the login keychain for that account.

When using this via SSH, you will need to sudo, otherwise it will fail.

And it goes without saying that this should NEVER be attempted on an account that has been filevault encrypted!

Enable Users to resume printers

If you are having an issue where your users printers keep on getting paused, then you will want to make use of the following solution

You will need to edit the cupsd.conf file, this is located in /etc/cups/

You will need to be in an admin account, or if in a users account then su into an admin account

Then open a Terminal and type the following

sudo nano /etc/cups/cupsd.conf

Now look for the following section

# All administration operations require an administrator to authenticate…
<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>

Now comment this out or delete it, entirely up to you, but I prefer the to comment it out as a fall back option in the event of an error

Now add the following section just under the commented section

# Allow non-admin users to add printers
<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
Require valid-user
Order allow, deny
Allow all
</Limit>

Now find the following section and comment it out

# All printer operations require a printer operator to authenticate…
<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
AuthType Default
Require user @AUTHKEY(system.print.operator) @admin @lpadmin
Order deny,allow
</Limit>

Now add the following section under the commented section

# Allow non-admin users to pause and resume printers
<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
Require valid-user
Order allow, deny
Allow all
</Limit>

Press CTRL-X, then press Y, then press ENTER to save the file
THIS KEY COMBINATION WILL OVERWRITE THE EXISTING CUPSD.CONF FILE!

Now log in to a user account, and test this by pausing a printer and trying to resume it, if all has been done correctly then this should resume the printer with no issues.

Mac startup keys

You can change the way that your mac boots by pressing & holding the following key combinations as the machine starts up

Option (ALT) – Display all bootable volumes

This will normally show you any internal hard drives, CD’s or DVD’s which are currently capable of booting from as well as external hard drives, USB keys, CD’s or DVD’s which could be used to boot the machine. If you have bootcamped your mac then this will enable you to choose between OS X or Windows.
If you have set a firmware password, then you will be presented with a padlock and a box to enter a password.

Shift – Safe Boot

This will disable any non system startup items, this can be very useful in troubleshooting a variety of issues.

C – Boot from CD

Hold this down until the machine boots from the CD, this can take a while sometimes so I would recommend the ALT method for this, this will be disabled if a firmware password is enabled.

T – Target Disk Mode

This will basically turn your mac into an external hard drive, connect it to another mac & you will have full access to all data on the machine, this will be disabled if you have a firmware password enabled.To boot into Target Disk Mode with a firmware password enabled, you will need to log in, and then select the Target Disk Mode option from within the Startup Disk preference pane located in System Preferences.

N – NetBoot

Startup from a NetBoot server.

X – Force Mac OS X Startup

This can be used if you have multi-boot machines and have set the default disk to be a non mac partition.

CMD-V – Verbose Mode

Verbose Mode shows you all that is going on whilst your machine is booting, very useful in troubleshooting as you can spot the faulting items.

CMD-S – Single User Mode

Command Line Interface, should only really be used for machines that are having serious issues, you can run a file system check (fsck) or Applejack if you have that installed.

CMD-R – Recovery Mode

On Machines with 10.7 installed then this will normally boot from the Recovery partition, although I believe the new Mac Mini Servers will connect to the internet and run a recovery over the net