Don't understand why TimeMachine stops before end of backup

Question

Hello,
I wish I use TimeMachine to backup my computer. When the TimeMachine process starts, the dialog box with the progress bar says "saving xxx/93Mo". However, the backup process stops by itself at 65 Go (!!) and the Console says the data were saved sucessfully ... If I check the data size that have been saved, I see 65 Go used too on the external hard disk. However, as far as I know, TimeMachine does not process any compression ?
I checked the external hard disk used to save datas : it is a Western Digital 750 Go with 2 partitions, the second one (200 Go) being dedicated to TimeMachine. Before every test I did, the 200 Go partition were erased. I saw a Warning at Apple.com about MBR-encoded partitions. My Hard disk uses a GUID encoding (thus not MBR encoding) for the partitions, and each partition is journalised HFS+ formatted ...
I saw also there are problems with spotlight combined with TM, and I inserted the external hard disk in the Spotlight exception list and reboot.
I think, perhaps, TimeMachine dislikes a single file over the whole hard disk ... Is there a way to know at which file the process stops ? Moreover, is there any file-size limit during the backup process ? I use VMWare Fusion 2 and I have a 20 Go file that is the PC's hard-disk ... and this file is not present in the TM Backup ... I saw some old versions of VMWare (<1.1 i think) forced TM not to save the HardDisk, but it does not seems to concern more recent versions ...
Is it simply a TM bug ? should wait for a next version ? or is there something wrong in what I do ?
Best Regards,
Mikhael Myara

Answer 1

Mikhael MYARA wrote:
as far as I know, TimeMachine does not process any compression ?
Hi, and welcome to the forums. Correct, TM does not do compression.
I think, perhaps, TimeMachine dislikes a single file over the whole hard disk ... Is there a way to know at which file the process stops ?
Corrupted files can cause problems for TM, but it will send error messages to your logs and a Failure message, as it should, rather than just skip the offending item(s). That does not appear to be what's happening here.
Moreover, is there any file-size limit during the backup process ?
No.
I use VMWare Fusion 2 and I have a 20 Go file that is the PC's hard-disk ... and this file is not present in the TM Backup
That file is probably listed in the +Do not back up+ panel of TM Preferences > Options. And you really don't want TM to back it up: since it's a single file to OSX, the smallest change to it will result in TM backing-up the entire file!
If you haven't found the Time Machine Buddy widget as Barry suggested, Click here to download it. It shows the messages from your logs for one TM backup run at a time, in a small window. If you're not clear about them, copy and post them here.
Most of what's "missing" is explained by that PC file.
Time Machine automatically excludes some other things, mostly caches, logs, workfiles, trash. These usually aren't significant, but if yours are quite large, it could explain the remaining difference.
From a Finder window, select Go > Go to folder, then type /var/ in the box provided. If it's not in List mode, select View > As List. Then select View > Show View Options, and click the +Calculate all sizes+ box.
See if any of the folders listed, particularly vm and logs, are in the multi-GB range. If so, that may be an indication of a problem, and also a reason for the difference in sizes. If either is very large, click the disclosure triangle to see the contents, and post the names of anything suspiciously large.
Caches are harder to measure, as they're in various places. One quick thing is, if you use Safari, to clear it's cache (Click Safari in the menubar, then +Empty cache+ ). See if that gains a lot of available space.
Of course, all these will only show how much is in use when you check, not when the backup was done. A Restart and/or some of the Mac's normal maintenance routines may reduce them.