[bma_mat99]

Noob question, i know, but hey, im just a kid who had to change to mac from windows (parants bought me a dual 1.8ghz g5....the older version that can be upgraded to 8gbytes ram). anyway, i used to do all kinds of stuff on my windows computer like defragment, scan disk, etc. just wondering if its a good idea to do repair permisions once in a while, and if it is...what does it do? thanks.

[Anubis IV]

Reparing permissions does just what it sounds like it does: it repairs the permissions of the files and directories on your system. It's a pretty useful thing to do, and, personally, I'd recommend doing it at least once a month, but there are people here that would suggest you do it after every installation while there are others here that have gone years without ever doing it. Really, it just helps your system to access things that it needs to access and make sure everything is in working order.

As for defragmenting and such, I know it's possible by using some of the Norton products out there (*sudders*) but I don't know of any applications included as standard software that can do it for you. Dunno about Scan Disk either.

[JKT]

Defragmentation of your hard drive is one of those things that you really do not need to do unless you are doing a *lot* of large scale file manipulation (that is reading/writing many large or hundreds of thousands of small files to the disk). I'm of the belief that it is largely unnecessary, and if it is, you are simply better off reformatting and re-installing from scratch anyway - you should never defrag a hard drive unless you have backed it up, and if you've backed it up why not simply start afresh and give yourself a nice clean new system free of all the cruft? FWIW, OS X 10.3.x has an in-built defrag routine that prevents fragmentation of any files smaller than 20MB anyway.

Repair permissions:

due its basis on a *NIX foundation, OS X assigns permissions to every file on the hard drive. These permissions tell the system who owns the file (the system, you, another user or a group of users) and what others can do with it (read and write, just read, have no access at all). Incidentally, this is what prevents you from accessing someone elses home folder and vice versa.

When you install an application from a .pkg file, it generates a "Receipt" file in the /Library/Receipts directory. This receipt tells the system what permissions each installed file should have. Some installers (especially third party ones like VISE) can muck up these permissions so that they don't correlate with those indicated in the Receipt for the install. The Repair Permissions routine simply checks the permissions of files against those Receipts and corrects any that are wrong. An extreme example of where a VISE installer has mucked up things for me was when it changed the permissions on my Applications folder and made it impossible for me to copy anything to or from that folder. If you want to get an idea of what type of permissions are applied to various files and folders, select something in the Finder and press command-option-I to "Show Inspector") and take a look at the permissions settings there. Then click around the Finder - the Inspector window will update automatically to show the info for each selected item (or items).

Contrary to popular belief, Repair Permissions cannot reset permissions on files which have not been installed via the .pkg mechanism...

It is worthwhile running it periodically just to check that things are up to scratch, as a part of routine maintenance. I always run mine before/after a software install or system update as a precaution.

HTH.

[cszar2001]

I´m using the Pilot feature in Cocktail about once a week.
Does that take care of all the routine maintenance?

[fiesta cat]

Originally posted by bma_mat99:
Noob question, i know, but hey, im just a kid who had to change to mac from windows (parants bought me a dual 1.8ghz g5....the older version that can be upgraded to 8gbytes ram). anyway, i used to do all kinds of stuff on my windows computer like defragment, scan disk, etc. just wondering if its a good idea to do repair permisions once in a while, and if it is...what does it do? thanks.

Like JKT said, OS X 10.3.x defrags 20MB+ files on it's own, so you really don't need to worry about it. The filesystem is much better and much more different than the older filesystems that Windows uses, so you kinda have to leave that mindset behind.

[Thorin]

Originally posted by JKT:
Repair permissions:

Thanks for that explanation. I knew what repair permissions did, and why it was helpful to run it regularly, but I didn't know how the permissions got mucked up, or how OS X knew what the correct permissions should be. Very informative, thanks!

[JKT]

Originally posted by fiesta cat:
Like JKT said, OS X 10.3.x defrags 20MB+ files on it's own, so you really don't need to worry about it. The filesystem is much better and much more different than the older filesystems that Windows uses, so you kinda have to leave that mindset behind.

Small correction - that should be 20MB and less, not 20MB+

From what I can remember, the Pilot thing in cocktail does also include a Repair Permissions routine? If so, it is doing what Disk Utility is doing.

[Fonzie]

abit off topic, i think; Whenever I repair permissions I always get a notice about that Disk Utility had repaired some "isocd9660" file. I cannot remember the real name. I will do the routine now and let you know. But can someone explain why this occur EACH time ?

edit:

Here's the output:

"We are using special permissions for the file or directory ./System/Library/Filesystems/cd9660.fs/cd9660.util. New permissions are 33261
The privileges have been verified or repaired on the selected volume

Permissions repair complete"

[mhodos]

I am also a noob, but I believe that maintenance tasks (akin to windows scandisk, etc.) are performed by the OS at regular intervals, but usually late nite/early morning. It is beneficial, then, to leave the computer running 24/7 for these tasks to occur.

I believe these are periodic tasks that occur daily, weekly and monthly. They can also be run from the terminal, using the 'sudo periodic daily/weekly/monthly' command.

Have I learned anything correct/useful?

Mike

Apple User from 1986 thru 1992, 2004 and on

[tooki]

Originally posted by JKT:
Contrary to popular belief, Repair Permissions cannot reset permissions on files which have not been installed via the .pkg mechanism...

That's not quite true -- yes, installs using .pkg generally leave behind a receipt. But non-.pkg installers can also leave a receipt, and some do. As Mac developers learn and adapt to permissions, we are seeing more programs that leave receipts, regardless of the installer used.

Originally posted by Fonzie:
abit off topic, i think; Whenever I repair permissions I always get a notice about that Disk Utility had repaired some "isocd9660" file. I cannot remember the real name. I will do the routine now and let you know. But can someone explain why this occur EACH time ?
..."We are using special permissions for the file or directory ./System/Library/Filesystems/cd9660.fs/cd9660.util. New permissions are 33261
The privileges have been verified or repaired on the selected volume

It's a common thing, just ignore it.


tooki