SD! doesn't seem to run

[klassa]

I have a machine that I upgraded to SL... Prior to that upgrade, SD! was scheduled to run nightly, and back up to a mounted disk image -- and it did. Faithfully. Since the upgrade (or at least, around that time; I'm not positive that the two are related), SD! no longer does its thing.

I haven't sat around to watch it (it's scheduled for the wee hours of the morning), but the backup image certainly isn't getting updated, and there are no indications in the SD! log that it's even starting to do anything.

I've tried re-creating the schedule from scratch, and that didn't fix it. "crontab -l" suggests that things definitely *are* scheduled, too. I'm not sure what else to try...

[dnanian]

You've tried scheduling it for 'a few minutes from now' and watching? If so, it sounds like cron isn't running...

[RobLewis]

This sounds like the problem I've been having.

BTW, I understand that Apple is discouraging the use of cron for scheduling things, and has a recommended alternative (launch services?). Can you explain the difference?

[dnanian]

This isn't the problem you're having, actually, based on what you've said - I think your Mac goes to sleep before it gets a chance to run.

launchd is a "more modern" version of cron, and while more flexible (we use it for backup-on-connect), it's also not really "better" for scheduling, because it offers up nearly all the same restrictions, etc. And Apple can't (and won't) get rid of cron, because it's a very common part of Unix.

[klassa]

Originally Posted by dnanian

You've tried scheduling it for 'a few minutes from now' and watching? If so, it sounds like cron isn't running...

Have only been able to play with it for a few minutes at a time... However, I tried scheduling it for a few minutes ahead, and it didn't fire up. I tried a simple cron test after that (to "touch /tmp/foo"), and that did work. So, cron appears to be running. SD! just doesn't seem to want to wake up, when cron comes knocking. :-(

[dnanian]

What are the names of the drives involved? What version of SD? Anything in the console that might indicate a problem when it tries to run (and you're sure you ran the local crontab)?

[klassa]

Originally Posted by dnanian

What are the names of the drives involved? What version of SD? Anything in the console that might indicate a problem when it tries to run (and you're sure you ran the local crontab)?

Sorry to be so slow in responding... This hasn't been a critical issue because they do have an external drive attached, to which Time Machine is doing its thing.

Anyway, I don't have any of the details you asked for (typical user, I know :-)) but wanted to mention that I was wrong about SD! and cron. If I'm logged in and am the active user, SD! fires up like it should, and everything works. If I'm not the active user (but am still logged in), it doesn't work.

I believe it used to be that, so long as I was logged in (even if the system was back to showing the login window), it would work. I'm almost positive that was the case, because that's how the machine lives (I stay logged in, but my kids come and go, and always log themselves out so that the login window is what's showing).

[dnanian]

Things changed as of Leopard to restrict non-frontmost application execution, and rather then crash or cause weird 100%-CPU-use-by-scripting problems (which is what started happening), we check for this situation and do not run.