verification phase of DVD backup causes system crash

[HelenHolzgrafe]

I am backing up a machine running 10.3.9 using the new 6.1 Retrospect. (This problem also existed when I was using 6.0, but not 5.X). I am backing up to a brand new DVD backup set each time. The DVD burner is a firewire DVD burner I have been using to make backups via Retrospect for several years. Testing this 3 times I have now wasted 18 DVDs on this.

 

The backup goes along merrily filling up 6 DVDs full of backed up files. Then it asks for disk 1 again to start the verification just as it should. I put disk 1 in DVD drive and my mac immediately gets the famous "you must reboot your machine now" in multiple languages screen. A look at the log file shows that it does not even get to the point where it notes that the file comparison has begun.

 

So, I try everything the same, but make the backup set a file on my huge firewire disk drive just to see what happens. That works just fine!

 

So, what happened between 5.X and 6.X that causes this failure?

 

I think the backups themselves may be just fine, but I will never trust a backup that did not go through verification. Is there a way to "Restart" retrospect at the point where it does the verification of a backup?

 

Thanks, Helen

[natew]

Hi

 

This is a kernel panic. Normally kernel panics are caused by hardware problems.

 

Have you added any new firewire devices to the machine? Try running a backup with all other firewire devices disconnected. Also try plugging the DVD drive into another firewire port.

 

Thanks

Nate

[HelenHolzgrafe]

Okay, I can try part of this. There is only one firewire port on the machine. I can try disconnecting the large firewire drive. However, that is what I am actually trying to back up..... That would isolate which piece of firewire hardware - the firewire dvd drive, the large disk drive, or maybe the firewire port on the machine itself - is the culprit. There are no other peripherals on this machine. I will also try backing up another machine with this DVD drive.

 

Thanks,

Helen

[natew]

Hi

 

I have seen many cases where the built in Mac firewire ports are flaky in OSX. The best way to fix that is to add another firewire card to the machine. It isn't too expensive and will likely resolve this problem.

 

Thanks

Nate

[HelenHolzgrafe]

This is an IBook running 10.3.9 and using Retrospect 6.1. The DVD drive is an older EzyQuest BOA. Can't add a card to an IBook, but maybe a hub. I am still just using the built in firewire port as I no longer think this is a firewire problem. Here's what I know now that has me worried:

 

If I do a backup of both the main drive (1st) and the firewire drive (2nd) into one backup set I always get the kernel panic when it tries to compare the backup of the main drive before even trying to backup the firewire drive.

 

If I back them up to two different backup sets there is no problem with either backup - both the actual backup and the compare work fine for both.

 

What is going on? What does Retrospect do differently when backing up multiple disks as opposed to single disks that causes this problem?

 

Thanks,

Helen

[twickland]

Are you running an Immediate Backup when you get the kernel panic? In an Immediate Backup, all volumes are scanned and matched before the backup begins.

 

If you back up each drive separately to the same destination backup set (i.e., run an immediate backup of one drive, then run the backup again for the second drive), do you still get a kernel panic?

 

If you create a backup script listing both volumes and then run the script, do you still get a kernel panic? (An "automated" backup script will scan, match, back up, and compare the first volume before attempting to access the next volume.)

[HelenHolzgrafe]

It is an immediate backup of both drives to one backup set. This causes the kernel panic. The panic happens when the verification of the first drive's files starts.

 

If I do two separate immediate backups to two separate backup sets there is no kernel panic.

 

I didn't try a backup script for this. The point was to get the last files on this machine backed up before upgrading to Tiger so I didn't intend to worry about a script until setting up after the upgrade.

 

The actual upgrade has not yet happened, however, so I will have to do this backup yet again as the machine is still in use.

 

This machine only has 1Gig free space on it's main disk. I hadn't realized how full it was as it is not a machine I use often.

 

Could this have something to do with the problem? Does Retrospect have minimum free space requirements to run?

 

-Helen

[CallMeDave]

Quote:

---

Does Retrospect have minimum free space requirements to run?

 

---

 

Not specifically. But OS X most certainly does.

 

Panther included a warning dialog box that will tell you:

 

"Your startup disk is almost full"

 

here's a link to a picture of it on the Apple site, but amazingly I can't find any tech support documents there as to how this dialog box is reset if you've checked the "do not warn me about this disk again" checkbox.

 

Still, as problematic as disk space can be (mostly with major disk thrashing as the system attempts to utilize virtual memory swap files), it may not be the cause of kernal panics (which are, as Nate suggested, more often caused by physical devices and the software that controls them).

 

> If I do a backup of both the main drive (1st) and the firewire drive (2nd) into one backup

>set I always get the kernel panic when it tries to compare the backup of the main drive before

>even trying to backup the firewire drive.

 

When you say always, do you mean even if there is no disk swapping involved?

Or have all your tests been with large enough data sets to require multiple members?

 

If you construct an Immediate Backup of2 defined subvolumes, one on each drive, containing enough total data that would fit on a single physical media member, do you get a panic?

 

It would be helpful to isolate the problem to situations where there is disk exchanging or not.

 

Twickland asked: "If you back up each drive separately to the same destination backup set ... do you still get a kernel panic?"

 

To which you replied: "If I do two separate immediate backups to two separate backup sets there is no kernel panic."

 

But that is not the question he asked.

 

It would be helpful to isolate the problem to situations where the volumes are scanned in in advance or not.

 

Dave

[HelenHolzgrafe]

This machine has never actually gotten the "Your startup disk is almost full message" and we have not checked any "do not warn me again" checkbox. No other programs (including some very big graphic games) fail to work correctly.

 

In this case both disks are large enough to require multiple DVDs for the backup and I do always have to swap them in and out for the compares. The main disk requires 6 DVDs and the firewire drive requires 2 DVDs.

 

All tests have needed DVD swapping before the compare can begin because of multiple DVD members.

 

I was unaware that it was even possible to do separate backups of two different disks to the same backup set. I always thought you needed to use a separate backup set for each disk if you backed them up separately and you could only put both disks into the same backup set if they were backed up together. That's why I misunderstood the point of Twickland's question.

 

This machine is used heavily by my high school senior for homework and I cannot hog it for testing Retrospect when he has papers due.

 

When I can I will try to separately backup a subset of each disk that uses 2 or more DVDs for each hard disk into the same backup set and see if I can answer Twickland's question. (I would bet money on getting no kernel panic for this test)

 

I will also try the suggestion of only backing up a small portion of each disk (so all fits on one DVD) and see if I get a Kernel panic then. (I would bet money on no kernel panic for this one as well).

 

I will also see if there is a difference if I use scripts instead of immediate. (Toss a coin on outcome for this one).

 

I have another machine running Panther with fire wire disk drive that is the twin of the one on the machine I am having diffculty with. I just did a backup on that machine using immediate backup of both hard drives together into the same backup set. Both Hard drives needed multiple DVDs. This one worked!!!! The two obvious differences are that I used the internal DVD burner (as this machine actually has one) and not the fire wire DVD burner and this machine has plenty of spare disk space and a bit more memory. I will now try using the firewire DVD burner on this machine and see if I can duplicate the Kernel panic I see on the other machine.

 

I believe these tests will answer everyone's nagging questions (including mine). This will cost me a lot in wasted DVDs, but I do still hope to get an answer as to what is going on.

 

-Helen