What is ACL?

[JeffPell]

ACL problems persist

Hi,
I just bought a MacBook Air 1.8 GHz (i7). It's running Lion (10.7.3). I had been unable to do much (I kept getting "You don't have permission to..." notices) ...rather like others on this old forum...so I tried to Verify and Repair Disk permissions. It took 10 minutes (estimated by Disk Utility, but actually was 18 minutes) to verify, and there was a HUGE list of "ACL found but not expected..." messages. So, I tried the Repair Disk permissions. This was estimated by Disk Utility as 1 hour 05 minutes, but actually took almost two hours, with it reading "five minutes estimated" for almost a half hour.
Afterwards, I ran Verify Disk Permissions again, and there was STILL a *huge* list.
What's up???
I was directed to this forum when I was looking for an answer to that question, although I see that most of the members were using Leopard some years ago. I also note that the overly optimistic "they will delete the bogus "ACL found but not expected" error message in the next OS" wasn't accurate...it being now two OS's later!!
Basically, in addition to the What's Up?? question, I also wonder WTF? Can't they do anything right anymore?? Do we need another Microsoft with super-flaky OS's??
And while I'm at it...Firefox worked like a champ on OS 6. Now it is a dog. The rolling ball is in effect MUCH more often than not. What's up with that??

 

[JeffPell]

oops, I meant...

Oops, I meant that Firefox ran like a champ on OS 10.6

 

[zPolarBear]

more background on ACLs

I think the Lion King and Mer1in have described the ACLs quite well.
The chmod command could be quite useful; however, a little more light on why ACLs exist might help.

1) they fill in what some consider to be a weakness in Unix. Unix has Read, Write, and eXecute, but no Delete privilege control. If I remember correctly, I believe this means that you could have Write privs to a directory, but no Write privs to the files and yet you could Delete files that are not yours...an ACL can solve this.

2) ACLs can slow a system down. Granted, my experience on this is 20th century, but on a VAX system I was administering, we got a script that went ACL happy and put ACLs down several directory trees to 6 or more levels... This had a severe effect on processing. Our solution was to remove the ACLs and at the 1st or 2nd directory tell it to Inherit from parent. This restored full system speed. Lesson learned is: unix privs are light weight, and ACLs are not, but can be easily tollerated at near top levels.

Hence, recursively removing the ACLs from /Library and then restoring a (Delete) prohibit to all, might be the best.
Also, if your system is running at full speed, then the ACL 'fix' may have no noticeable benefit to you.

(also, no need to use mean cuss words on us...we're just trying to help, so please no more WT* acronyms...Thx)


also, you may hear sysops call them Ackles (sounds like shackles)...