Techsurvivors

Archives => 2003 => Topic started by: csonni on February 16, 2003, 05:14:00 PM

Title: what\'s truly necessary?
Post by: csonni on February 16, 2003, 05:14:00 PM
I suppose I'm a mild "geek" with my Macs.  I like to keep up on maintenance procedures, etc.  I see various "utilities" for X that perform various tasks, such as Cronation (to run Cron tasks- is this necessary?), Spellbinder (to update prebindings- is this necessary?), and others.  I find these all interesting, but am I wasting my time using these just to try to squeeze out every ounce of performance, or are these truly necessary tasks for OSX stability and reliability?
Title: what\'s truly necessary?
Post by: kps on February 16, 2003, 06:35:00 PM
Many of those little utilities were necessary in some earlier versions prior to Jaguar so if you download any, make sure they're still needed or even necessary for Jag.

The cron jobs consist of the three common unix maintenance scripts(daily, weekly, monthly) which, for the most part, do not affect performance. They rotate log files, update certain databases, backup netinfo database, etc. Get MacJanitor to run these from the GUI.

Prebinding is performed automatically in Jaguar.
Title: what\'s truly necessary?
Post by: kelly on February 17, 2003, 09:27:00 AM
The urge to Tinker vs "If it ain't broke don't fix it".  

Just came across this, haven't tried it myself.

Cocktail

"The application simplifies the use of of advanced UNIX functions and gives access to hidden Mac OS X settings."

http://www2.dicom.se/kristofer/english.html

Donationware.
Title: what\'s truly necessary?
Post by: CyberPet on February 17, 2003, 11:08:00 PM
Cocktail is written by a Swede, and yet he's not made a good manual explaining what all the tabs does. Anyone care to give an explaination... and also when some of those options are needed.
Title: what\'s truly necessary?
Post by: tacit on February 17, 2003, 09:56:00 PM
Available features :

• update prebinding information
This will cause applications to launch faster under certain circumstances. ("Prebinding" refers to the way applications locate shared libraries. It needs to be done if an application's shared libraries are changed--for example, when you update MacOS versions. This is something that happens automatically if you update OS X using the Software Update system panel.)

• enable or disable journaling (Journal File System)
This will turn on or off the 'journalling file system." MacOS X 10.2.3 and later have a journalling file system; this is a special kind of filing system that keeps a list of changes every time any program writes something to the hard disk. If you crash in the middle of writing something to the hard disk, you do not damage the hard disk directory (though the information is still lost, of course). Journaling slows down the computer significantly. Apple suggests that you only use it if you are running OS X Server on an Xserve computer.

• manually run Cron scripts
Cron is the name of a Unix program. Cron runs a list of commands at certain times. For example, you can instruct the computer, "Every Tuesday and Thursday at 7:43AM, execute this Unix command, then this Unix command, then this Unix command. Every day at 8:07 PM, execute this command."

• repair file and folder permissions
This will fix problems with file permissions.

• delete locked or unaccessible items
This will let you trash files that won't go away if you drag them to the Trash--for example, files that are locked or have permissions problems.

• view log files
Every time your computer starts, shuts down, has a program crash, runs a Cron script, or experiences an error of any sort, it records the date and time and what it was doing in a file. This file is called a "log file." All Unix computers do this.

• delete archived log files
The log files that the computer uses to record all sorts of information about crashes and so on get archived every day. The archives are stored for a long time. This deletes that archive of previous days' log files.

• create symbolic links
A "symbolic link" is a Unix "alias." It does the same thing as an alias--it is a pointer to another file. The only difference is in the way they work when you type Unix commands. You can type Unix commands that work with symbolic links; they don't work with aliases.

• change duplex and speed of network card
This lets you slow down the network hardware in your computer, or change it to half duplex. Useful only if you are attached to an antique router that can't automatically sense your network speed. This can get you in a lot of trouble if you don't know what you are doing. Use it only if you are sure you are having autosense problems on your network.

• request new lease from DHCP server
This forces the computer to go out to a DHCP server (for example, a cable modem server) and ask for a new IP address.

• force empty trash
This will empty the Trash if you have files in it and you can't empty the Trash because the file permissions are screwed up.

• recreate alias to Mac OS 9 desktop
The "Desktop" in OS X is not the same as the Desktop in OS 9. In OS X, every user has his or her own desktop. There is a special alias that OS X uses to "see" the OS 9 Desktop. If that special alias gets trashed, this command will re-create it.

• customize look and features of Finder and Dock
Self-explanatory.

• easily optimize your system using Auto Pilot
This performs many of these commands automatically.
Title: what\'s truly necessary?
Post by: kps on February 18, 2003, 12:04:00 AM
I want to expand on the prebinding a little...

In earlier versions of OS X to link dynamic libs and frameworks to certain installations (mostly the drag&drop installs) one would run the update_prebinding and redo_prebinding to speed up application launches...in other words save dyld the trouble of looking for these links itself.

With Jaguar (OS X 10.2.x) this is no longer necessary. Apple added a new daemon(service/process) called fix_prebinding which is evoked by the Mach_init when requested by dyld (dynamic link editor) when it finds an application which needs prebinding. This is done automatically when needed...no matter what.

See man fix_prebinding for more.

A little on cron...

The only thing cron runs in OS X (any version) is the three maintenance scripts daily, weekly and monthly and nothing else. The cron jobs are in etc/crontab and can be viewed in TextEdit.

It looks like this:
code:
# /etc/crontab
SHELL=/bin/sh
PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin
HOME=/var/log
#
#minute hour    mday    month   wday    who     command
#
#*/5    *       *       *       *       root    /usr/libexec/atrun
#
# Run daily/weekly/monthly jobs.
15      9       *       *       *       root    periodic daily
30      4       *       *       6       root    periodic weekly
30      5       1       *       *       root    periodic monthly
/etc/crontab (END)
Reading only the un-hashed (#) bits under the headings minute,hour,mday,month wday...., cron will run the daily script at 9:15am each day (not the default), the weekly at 4:30am on the 6th day (Saturday) and the monthly at 5:30am on the 1st of each month. The asterics(*) mean no value. If anyone wants to change these values, it's not that difficult to do. I changed the time for the daily script to run at a more 'normal' time, when i was sure the machine is on and not off or sleeping. If anyone cares to do that, then there's no need for MacJanitor or any other third party utility. I used BBEdit's Terminal tool, otherwise you'll need to use vi or pico...or emacs, none of which are user friendly.

If you want to run your own cron jobs, I know you can create your own user crontab and run it as you and not as root. How exactly, I'm not sure...never done it.