Faster Leopard after upgrade

[Amdahl]

I have upgraded a couple of systems from 10.4, and I noticed they did not run quite as fast. It appeared to me that the hotfiles database was not being updated. I booted into single user mode and deleted the hotfiles database file, and then rebooted.

It appeared to me that within one more reboot, the system was launching apps more quickly.

Does anyone suppose that having the 10.4 hotfiles DB around is slowing or preventing Leopard from getting itself up to speed?

Wouldn't the hotfiles DB be completely inaccurate after a replacement of the OS and libraries?

 

[Makosuke]

You sure that's not just placebo effect you're noticing? I was under the impression that the list of hotfiles was constantly updated, so not only would it have to be using the old database, but it would have to be not updating it as well. I don't see any logical reason this would happen.

On my 10.4 to 10.5 system /.hotfiles.btree is showing a mod date of about a month ago, which is a little surprising, but that's still after I upgraded to 10.5, so it's been modified since the upgrade, at least.

 

[Amdahl]

I used the dock bounce count to judge the change.

I think it would help because instead of the new files having to overcome the popularlty of the old files, everything starts fresh.

Using hfsdebug, I could see that dozens of entries in the hotfiles were non-existent files; the old system files.

One question though, is whether the hotfiles db is the actual DB? Because a fresh hotfiles db shows empty for awhile before it shows data. So, is the hotfiles db actually empty, or has the system just not decided to move its info into the public view yet?

 

[Makosuke]

I'd be interested in hearing from someone more familiar with the low-level workings of the hotfile system before I start second-guessing the OS.

It is interesting that the DB is clearly NOT updated constantly, and not necessarily after reboot. On a Tiger system, for example, it's showing last updated 9 days ago. On one of my two Leopard systems, it was updated yesterday, and there was no reboot around that time. On my other Leopard system, it was updated 24 days ago, and the machine has been rebooted at least twice since then.

The third of those three also has a .hotfiles.btree.swp file that was updated considerably more recently than the DB; I'm assuming this is swap space reserved for the hotfile moves, but it's interesting that the other systems aren't showing it (right now, at least).

Clearly it's not a simple algorithm, but I'm going to assume it's all functioning as it should unless I hear a more explicit explanation of from someone with deeper understanding of the system.