Time Machine error leading to Finder crash

Question

I have only started using TM recently, and over a wired network did the first backup. Then since then all other backups have failed using WiFi.
I have a MacBook (Core Duo from 2006) and a MacMini with a Iomega 1TB Firewire drive attached to it. Both mac are running OS 10.5.8
On the backup HDD, there is a file called: Macbook_0016cbcb6e19.sparsebundle
The MAC address of the ethernet connector is 0016cbcb6e19. That of the airport network doesn't appear. (I expected to see 0017f25371b4 in the sparse bundle name).
The initial backup was a total of 75GB. Then the next 4 hours, after not doing much changes, TM was starting the first incremental backup, but it was giving a message of backing up 20GB. This to me is strange as there have only been very small changes on the HD to back up. In any case, it seems to continue, and then always fail. An alert displays with the Iomega HDD is disconnected.
But if I do a ls on /Volumes it is still mounted. What is the difference between an afp mount and a TM mount? Or what causes the mount to fail or cause the disconnected window alert to show? Is TM more sensitive to signal interruptions than say screen sharing and terminal connections?
I did a check on the signal strength of the WiFi and placed a cron on the macmini:
Thu Nov 12 00:57:00 81 : Apollo9 10 packets transmitted, 9 packets received, 10% packet loss
Thu Nov 12 00:58:00 80 : Apollo9 10 packets transmitted, 10 packets received, 0% packet loss
Thu Nov 12 00:59:00 81 : Apollo9 10 packets transmitted, 10 packets received, 0% packet loss
Thu Nov 12 01:00:00 80 : Apollo9 10 packets transmitted, 5 packets received, 50% packet loss
Thu Nov 12 01:01:00 80 : Apollo9 10 packets transmitted, 9 packets received, 10% packet loss
Thu Nov 12 01:02:00 79 : Apollo9 10 packets transmitted, 10 packets received, 0% packet loss
Thu Nov 12 01:03:00 81 : Apollo9 10 packets transmitted, 9 packets received, 10% packet loss
The 79-81 value range is the signal given by the airport -I command agrCtlRSSI:
This shows that the signal occasionally drops but recovers.
I placed a shell script to automatically mount the network drive on the macbook when on the local network:
mkdir "/Volumes/$backupHd"
mount_afp "afp://$user:$pass@$backupServer/$backupHd" "/Volumes/$backupHd"
Is this necessary or will TM always mount the drive anyway?
When TM is running it mounts a disk image called Backup of MacBook once it has completed preparing. Then it also mounts "Iomega HDD-1". What is this disk mount for?
I have noticed that if I use ls -l /Volumes the terminal window will crash.
ls /Volumes will work ok though in a new shell window after than.
Then I use killall backupd and it stops the TM.
But then I notice that Finder is not responding. I try to restart Finder, but it doesn't work. Using the alt+tab to display all the currently running apps, Finder does not appear as a running app.
From the command line I try to launch Console but this also does nothing.
I have to control-C to stop it. then I have to use 'reboot' command, but this does nothing. Then I tried 'halt'. this also does nothing. A force shutdown is necessary. After rebooting the machine works OK. This pattern has happened 3 times now. It there any further troubleshooting I should do to try and fix this?
TIA.
Ronan.

Answer 1

ronanoc wrote:
I have only started using TM recently, and over a wired network did the first backup. Then since then all other backups have failed using WiFi.
You've got a number of things going on here.
First, when you say "wired network" do you mean you connected your MacBook to the Mini via an Ethernet cable?
I have a MacBook (Core Duo from 2006) and a MacMini with a Iomega 1TB Firewire drive attached to it. Both mac are running OS 10.5.8
On the backup HDD, there is a file called: Macbook_0016cbcb6e19.sparsebundle
The MAC address of the ethernet connector is 0016cbcb6e19.
That's how TM keeps track of which backups are for which Mac (not computer name or serial number).
TM was starting the first incremental backup, but it was giving a message of backing up 20GB. This to me is strange as there have only been very small changes on the HD to back up.
A number of things can cause extra-large backups. Unfortunately, the only way to be sure what it is, is to look at the completed backup via +Time Tracker+ to see what was backed-up (see #D4 in the Time Machine - Troubleshooting *User Tip* at the top of this forum. It also lists some of the common culprits).
Bur first, you need to find out just why the backups are failing. Start with #C2 of the Troubleshooting Tip. It will show you how to locate the message(s) that describe the problem, then help you fix it.
Is TM more sensitive to signal interruptions than say screen sharing and terminal connections?
Probably, because there's more going on, but it should recover.
Is this necessary or will TM always mount the drive anyway?
It should mount the sparse bundle when needed.
Then I use killall backupd and it stops the TM.
Don't do that unless you have to. Try to cancel the backup (from the TM icon in the menubar, or the TM Preference pane).
Since you've done that, you should probably do a +*Repair Disk+* on the TM drive per #A5 of the Troubleshooting Tip.
You might also want to try the things in #D2 there. Some of those things may help, but it sounds like your wireless connection is fairly bad.