#457 Time Machine backup unreliable

[pe^cjo]

I set up a Arch Linux box with an external drive(Ext4) and netatalk 3, to be my backup server.

My conf file contains just this:

[TimeMachine]
path = /media/backup
time machine = yes

It has been running for a few weeks now, and I already had trouble twice.

First I got "resource temporarily unavailable", which was resolved by rebooting everything.

Now, time machine failed to verify my backup and prompted me to start a new one. I'm not sure how to debug this, but an unreliable backup is as good as no backup at all.

[Scott Marcy]

I've experienced this, too, on an OpenIndiana (oi_151a5) box running netatalk 3.0 as part of napp-it. All filesystems are ZFS, including the TM volume. My backups go bad about every 10-14 days, but only on the machine that uses encrypted backups and Mountain Lion. I have two other Macs (one Lion, one ML, neither using encrypted backups) backing up to this same sharepoint and they haven't had this problem.

[John Muir]

I have the same problem. Once a month (when Lion fscks the 'sparse volume' for the time machine backup), my backup becomes 'unreliable'. Happened less often before I upgraded to netatalk 3.0.1.

[pe^cjo]

So the question remains if TM corrupts the disk, netatalk does, or fsck doesn't work correctly.

I found this blog post about how to fix broken sparsebundles on disks connected to an airport extreme. http://www.garth.org/archives/2010,07,16,124,fixing-time-machine-sparsebundle-network-backup-errors.html

To me this suggests TM might be at fault, as the airport extreme obviously doesn't use netatalk.

I also seem to recall that no sparebundle is needed on HFS+ volumes, but this might have been with local disks only.

[Daniel Markstedt]

Tentatively closing this. The reports are against ancient versions of netatalk. I've been running hourly backups for two days with 3.1.15 pre-release code, and a Ventura Mac, so far without incident. I will keep this running for at least a month to see how reliable it is.