We spent a long time trying to get our XServe Macs to talk serial to serial. Putting together many of the hints and pieces, we finally came up with a relatively simple Terminal solution. Just connect the serial cables together of two machines and run this on one of them:
This may help you out if you are running any server version of OSX on a desktop machine and are experiencing extreme slowness while starting new programs. I installed Tiger server on my desktop machine and was running into unexplained creeping slowness with applications. It turned out to be related to a memory hogging program that Server runs by default, called Web Performance Cache, or webperfcache (name of the program).
webperfcache performs a very useful function if you are serving web pages on the internet and want really high performance. It caches static web pages in memory to accomplish this, which is great if you're a web company, but is generally unnecessary for home use. The problem is it forces these pages to stay resident in memory, and has a negative impact on OS X's memory paging and swapping routines. Long story short, turning it off drastically improved the performance of my G4, and it might help you out, too, if you're the kind of person who runs Server at home as a graphical desktop.
To disable it, go into the Server Admin program (under Applications/Server) and click on the local node (your computer's name) under Computers and Services. Then select the Web service, and under this the Settings tab. There is an Options tab under settings that controls optional web server components. You should uncheck Web Performance Cache here and save your settings.
It can be re-enabled by checking this box again, but I can't see why anyone would need to.
I had big trouble with the Advanced Firewall settings in Server Admin. I had a lot of double entries in the rules list, but could not delete them. If I moved them up or down, they were copied instead of being moved. If I enabled a disabled rule and saved it, it was automatically disabled again. Many rule numbers were duplicated with different contents.
So here's the fix: Disconnect your server from the internet, then in Server Admin, stop the firewall. Quit Server Admin and open Terminal. Type in the following:
$ cd /etc/ipfilter
$ cp ip_address_groups.plist ip_address_groups.plist.orig
$ sudo open ip_address_groups.plist
Check, edit, and correct all the rules. To see a list of ports, use cat /etc/services. To learn how to set up rules correctly use man ipfw. When all rules are correct, then:
The scenario: I had an OS X Server which I had been accessing via ARD (Apple Remote Desktop). I had recently updated the ARD Client software to v3.1. This morning I needed to install the ARD Admin software on the same server (to use it as a Task server, probably the most useful feature of ARD 3). No joy. The installer complained that the software already installed was a later version than I was trying to install -- 3.1 Client on the server, 3.0 Admin on the install disk.
The reason this happens is that the ARD Admin installer package is actually a metapackage -- a package of packages, if you will. It contains a package for the Admin application and also one for its own version (3.0) of the client software. It's this package that's blocking the install.
The solution is a simple, if not immediately obvious, one. Control-click on the RemoteDesktop.mpkg icon and choose Show Package Contents from the pop-up menu. In the new window that opens, burrow down through Contents -> Installers, and find the RemoteDesktopAdmin.pkg installer. Double-click on that one and ... Presto! one fresh clean installation of ARD Admin.
But it doesn't stop there, sorry. The last thing you must do before launching it is update it with the ARD Admin 3.1 updater. You can use Software Update or download it from Apple's update site.
Managed printers (on managed clients) are convenient, but there are bugs. The problem is the system doesn't clean up after itself. One side effect is the user has old printer configurations that were deleted from the server (this can also result in what appears as duplicate printers, but the config was updated with the same name, or deleted and recreated). Another side effect is with computer list managed printers. For example, computer lab A has printer A managed only. Computer lab B has printer B managed only. The user logs into lab A, logs out, then logs into lab B. They shouldn't see the lab A printer at this point, but they do (because they logged into lab A once upon a time, and this saved in their home folder).
Read the rest for some workarounds to these problems...
There is a problem with managed clients and external displays: The user (a high school student, for example) can change the display to an unsupported resolution/frequency, rendering the display useless. When this happens, it's broken for that user on that machine, because of the By Host preferences folder. (What's with that folder anyways? I mean, why?) I know there is that warning and confirmation that will auto-revert, but sometimes it doesn't warn, when it 'thinks' it will work. Anyways, the kids manage to make the display black.
You can always lock out the Displays prefpane with managed preferences, but they can still switch it with the menu extra. So the simple solution is to take away read access for "others" on the menu extra:
I have seen a network user on a Managed Client logging in hang before the Finder and Dock load, so it just sits there with the desktop picture and only the Spotlight part of the menubar visible. The fix is simple. Delete these folders:
That should resolve the issue for the user whose login was hanging.
Like many OS X admins, I inherited a bunch of Macs which all look the same, but serve different functions. Since they all pretty much look the same from my VNC/Timbuktu/Apple Remote Desktop window, it's hard to know where I am when I log in. I can't tell which one is an Xserve, and which is a Mac mini...
I could place a folder with the name of the server in the Dock (along with sub folders or files named with IPs or hostnames for quick reference). Or I could use this hint (shameful plug, I know). The problem is, with all of the monkeys' changes, I have more important things to do than modifying screenshots all the time...
Enter our friend GeekTool. Set it up to read/display a text file of the services on the box, as well as current IP addresses and or hostnames, and you've got a dynamic 'desktop' which displays useful information. Someone who's handy with shell scripting might know how to write the scripts to grab the IPs and/or hostnames on the fly. That'd make for a really nifty and useful hint. Happy administering!
I have been running a host monitoring solution (among other things) on an Xserve G5 for about a year now. It has been rock solid stable and has proven to be better than any other solutions I've looked at. It uses Nagios and sendPage, installed on OS X Server.
[robg adds: Typically I would ask the author's permission to mirror the actual writeup here. However, in this case, the provided solution is quite lengthy and detailed, and may not be of interest to a huge number of readers, so I think a link to the writeup will suffice.]