Timemachine - Backups have gone

Question

Hi All,
This is my first post, so be gentle!
I backup to a Western Digital MyBookWorld 2TB NAS drive.  Since upgrading to ML I've twice experienced a total loss if my timemachine backups.
On each occassion I've noticed because TM starts doing a full backup - which I stopped.  Going to TM preferences showed no previous backups the first time it happened.  Today I went into TM (trying to find a backup of my iPhone in an attempt to get my iOS5 back after discovering the joys of the new Maps app - but that's another story) there were no backups before today, though TM preferences showed a backup from last night.
Anyways, I don't really understand what has happened so I looked at the TM logs - which I also don't understand, but it looks like something went wrong. Do any of you folk know what has happened and do you have any advice? My goal is to have dependable backups. Would I be better off buying a TimeCapsule?
Thanks,
Marc
Log follows!
Starting automatic backup
Attempting to mount network destination URL: afp://[email protected]/WD_Backup
Mounted network destination at mount point: /Volumes/WD_Backup using URL: afp://[email protected]/WD_Backup
Runtime corruption detected on /Volumes/WD_Backup/Jazzbook.sparsebundle (fsck_hfs -q termination status: 3)
Network destination already mounted at: /Volumes/WD_Backup
Recovery backup requested by user.
Deleted backup image: /Volumes/WD_Backup/Jazzbook.purgeable.  1.21 TB available on host volume.
Creating disk image /Volumes/WD_Backup/Jazzbook.sparsebundle
Failed to hide extension on /Volumes/WD_Backup/Jazzbook.sparsebundle, error: Error Domain=NSCocoaErrorDomain Code=4 "The file “Jazzbook.sparsebundle” doesn’t exist." UserInfo=0x7fa553101bd0 {NSURL=file://localhost/Volumes/WD_Backup/Jazzbook.sparsebundle/, NSFilePath=/Volumes/WD_Backup/Jazzbook.sparsebundle, NSUnderlyingError=0x7fa553101530 "The operation couldn’t be completed. No such file or directory"}.
Disk image /Volumes/WD_Backup/Jazzbook.sparsebundle mounted at: /Volumes/Time Machine Backups
Backing up to: /Volumes/Time Machine Backups/Backups.backupdb
Network destination already mounted at: /Volumes/WD_Backup
Ownership is disabled on the backup destination volume.  Enabling.
Forcing deep traversal on source: "Macintosh HD" (mount: '/' fsUUID: 95006285-5C79-3F83-A602-7E1F34A880A8 eventDBUUID: B9F80CBA-6506-4FFA-A542-44247E5038FF)
Disk image already attached: /Volumes/WD_Backup/Jazzbook.sparsebundle, DIHLDiskImageAttach returned: 35
Disk image /Volumes/WD_Backup/Jazzbook.sparsebundle mounted at: /Volumes/Time Machine Backups
Backup content size: 414.6 GB excluded items size: 8.65 GB for volume Macintosh HD
Found 936300 files (405.95 GB) needing backup
487.14 GB required (including padding), 1.21 TB available
Waiting for index to be ready (100)
Copied 4.64 GB of 405.95 GB, 1 of 936300 items
Copied 7.88 GB of 405.95 GB, 90085 of 936300 items
Copied 10.65 GB of 405.95 GB, 244278 of 936300 items
Copied 13.99 GB of 405.95 GB, 327686 of 936300 items
Copied 17.93 GB of 405.95 GB, 438898 of 936300 items
Copied 21.94 GB of 405.95 GB, 469320 of 936300 items
Copied 25.93 GB of 405.95 GB, 482815 of 936300 items
Copied 29.55 GB of 405.95 GB, 507353 of 936300 items

Answer 1

Hi there,
I had the same problem yesterday on my old MacBook Pro 15". I have a 2TB Western Digital harddisc connected to my Airport Extreme, so it is actually nearly the same as the Time Capsule, with the only difference that my hdd's are external and not built in. This 2 TB disc is divided into two partitions, one is the time machine partition from my newer macbook pro 13" and the other one for the older 15".
This configuration was working perfectly via WiFi for nearly two years now, at the beginning with Snow Leopard, then with Lion and now with Mountain Lion.
So to cut a long story short, yesterday the old MacBook reported, that the last update is already more than 11 days ago and that it has todo a full backup with over 120GB. As this surprised me completely I checked the backup disc and noticed that it was nearly empty. It seems that the complete image file (in case of WiFi backup the backups are placed in an image file) for the time machine backup was deleted and a new one was started.
I even checked the console logs and it was stated there, that there was a partially deleted file found, which was afterwards deleted and then a one was created. I haven't got the logs here now, but it was nearly the same as in the log from maz100 with the only difference that it did no report me "runtime corruption" on the image file, it reported me a "partially deleted file" found.
I checked also the other partition on that disc and the backups from my 13" book are still there. So I got no clue why the complete image file of my 15" book has been deleted and a new one has been created, it's running now since yesterday to make the new full backup.
For me it seems as the image file of the TM backup got currupted somehow and was replaced by a new one. It is a bit strange for me, that this is done without stating any information to the user as you actually loose all your backups. Till now I felt quite secure with the backups, it was good to now that there are still backups, when you delete something accidentally, but if complete backups are disappearing I'm loosing my trust in these TM backups a bit, not speaking about the time it takes to perform a complete new backup via Wifi.
....and it seems, I'm not the only one around here. I'm afraid it has to do with my recent Mountain Lion Backup as it did not come up for years with SL or Lion.
Greetings
Bernhard