Disk Utility: Extremely slow read phase during permissions repair

Have you tried repairing your hard drive using Disk Utility? You may have some drive damage that's causing this. (You also could have some system problems, but that gets a little harder to troubleshoot, so start with the easy stuff.)

Also, although this does not address the problem, note that repairing permissions isn't something you need to be doing frequently. See:

http://www.macworld.com/article/133684/2008/06/maintenance_intro.html

Repair Permissions is much slower in 10.5 than it was in 10.4 or 10.3. Nothing new here, this is normal (if annoying). It's faster from the command line (sudo diskutil repairpermissions /).

Still, RP really is almost never necessary. So many threads here and concerns about people worrying about the treatment, when there's actually no symptom to cure! It's almost NEVER necessary, and there's so much silly lore around it (crud like "do it before and after every system update!" which is totally unnecessary), it's almost become its own vortex of doom.

That is an opinion not shared by all.

http://docs.info.apple.com/article.html?artnum=25751

and here:

http://docs.info.apple.com/article.html?artnum=302672

An article on troubleshooting Permissions can be found here:

http://support.apple.com/kb/HT2963

You know, don't you, that "Repair Permissions" doesn't actually REPAIR anything?

It does one thing: It goes through the BOM file (and, now with 10.5, the database as well), and compares the permissions on system files and on applications installed that put a receipt in there, and RESETS the permissions to whatever the BOM files and database say. Nothing more, nothing less. NO ISSUES related to the users home folder can be repaired in any way, because there are no receipts for them.

I'm not saying there aren't a set of very specific issues that "Repair Permissions" can't fix. But to say it should be regularly used to troubleshoot and as proactive maintenance is like recommending chiropractic care to fix a hangnail. It probably does more harm than good, as there may be cases where you actually WANT to change permissions, and "Repair Permissions" stomps all over them.

Nothing to add 😟

Leopard goes even further than TIger, in that not only are Access Control Lists available, they are enabled by default and actually used. It would appear that in addition to the normal POSIX permissions, going though the ACL entries of tens of thousands of system and application folders takes a while.

Just bringing in a little more data into this thread from another one I have been working on. My iMac G5 exhibited several strangenesses, not least a locked Time Machine disk and a refusal to load new programs, and in an attempt to put things right I did a 'Repair Permissions' using DU and it took MORE THAN FOUR DAYS. It was all ACLs, whatever that means. Anyway as you can guess, all I could conclude from this was that my machine (or rather the OS - since the disks had been checked) was very sick and I ended up re-loading Leopard from the install disks, doing all the updates, and erasing my TM disk, which so far (early days) seems to have fixed everything. All of which points to the idea that the slow permissions thing may be a symptom of something else, though what exactly was wrong I have not been able so far to find out.