Replace file after 2+ reboots?

[onyx00]

I am looking for a way to replace a file after a certain number of reboots.

More specifically, say I corrupt a file like dssapp or tivoapp; I want a way to automatically copy back the old file. Something to prevent me from having to pull the hard drive.

Anyone have any ideas?

[PlainBill]

Automatically isn't a very good idea. It would require you to insert the 'watchdog' after modifying anything, then remove it if everything is working OK. Forget to insert it and a error will force you to pull the drive; forget to remove it and a power failure a few weeks from now will undo the changes. OK, some really clever coding will ensure the undo occurs only if the two reboots occur within 2 minutes.

I prefer a second approach: Use the crypto command to set up a known password. Duplicate a good root file system to the alternate partition, modifying fstab so the proper partition gets mounted in each case. If you encounter a problem, hitting a key on your serial terminal will bring up the prom menu, and you can boot to the alternate (unmodified) partition. The chief disadvantage is you must have a serial connection.

Some of the elders (AlphaWolf, alldeadhomiez) have mentioned inserting a delay in rc.sysinit. If you hit a key in that time it will boot to a minimal system. You must have a serial connection or load network drivers VERY early.

PlainBill

[BTUxNine]

Some of the elders (AlphaWolf, alldeadhomiez) have mentioned inserting a delay in rc.sysinit. If you hit a key in that time it will boot to a minimal system. You must have a serial connection or load network drivers VERY early

FWIW, the delay that is mentioned is prior to loading author (to let the tivo boot up faster), it doesn't delay loading tivo s/w

Loading networking early is probably your best bet... you CAN check for most reboot-loops by creating a file on boot that only gets deleted after author finishes, but it can be self-defeating (a brown-out situation could leave your tivo s/w not running). During a reboot loop, if you connect to your box early on, you can type "skill -9 /etc/rc.d/rc.sysinit" at bash to stop the tivo s/w from coming up fully, that should allow you to fix most things.

[onyx00]

How about I do this:

1. At the beginning of rc.sysinit check for the existence of a file name "fixme.log"

2. If fixme.log exists, then replace some file (that I was messing with) with a backup

3. At the end of rc.sysinit.author delete "fixme.log"

So if I do the above in the mentioned order it should allow me to replace some file with a backup copy. Possibly I could expand it to read "fixme.log" and read the filename that needs to be replaced with a backup?

Sound like a plan?

The main file I am messing with, dssapp, shouldn't cause the system to die, but just in case...

[BTUxNine]

That's certainly doable, but keep in mind, there ARE times that a tivo reboots without completing rc.sysinit.author... anytime that happens (and rc.sysinit has been run), your file would be replaced.

[tivomaster]

How about I do this:

1. At the beginning of rc.sysinit check for the existence of a file name "fixme.log"

2. If fixme.log exists, then replace some file (that I was messing with) with a backup

3. At the end of rc.sysinit.author delete "fixme.log"

So if I do the above in the mentioned order it should allow me to replace some file with a backup copy. Possibly I could expand it to read "fixme.log" and read the filename that needs to be replaced with a backup?

Sound like a plan?

The main file I am messing with, dssapp, shouldn't cause the system to die, but just in case...

You might take a look at this thread StopLoop....