Backup fails validation but restores fine

[Jeremy]

Hi,

I am using version 2.2.0.271 of AISBackup to backup a directory of large files to DVDs using the integrated writer. The backup is chopping up each file into roughly 7 segments of 100 MB each. I got about 6 files per DVD in this manner.

None of the original files is smaller than 100 MB, so I get no ZIP files on the DVD at all. The discs contain mostly .AIL files. A test restore successfully copied the original files back to the hard disk and they seem to be good.

However... if I go to Manage Backup -> Validate (Test) Backup -> Load Backup Files and then select the first file on a DVD, every segment on the DVD reports an error.

Sometimes the test for a segment fails very quickly, other times it seems to take a minute or two. All tests seem to fail though.

If I hit Abort, then try to select Validate (Test) Backup again, nothing happens. If I then exit, AISBackup crashes.

Any suggestions? I don't appear to be having any fatal problem, but I'd like to know why the validate is failing.

Thanks!

Jeremy

[Jeremy]

Oh, some extra information that may be helpful.

The first time I ran this backup, I aborted the backup after the first disc was created, when AISBackup asked me to put in a new blank media.

Also, I am now getting an error message dialog during backups in between when the files are staged to disc, but before the Disc Writer Interface screen pops up stating that errors exist in the backup contents file and I should run a validate. Of course, that is where my previous post starts...

Jeremy

[Barry]

I created a ‘huge file’ backup to DVD and aborted it after 1 DVD, I then resumed the backup and had the same result as you, i.e. the “The Backup Contents file was damaged” fault. A fix is been worked on.

I did not get any problem validating, however I aborted the first run and de selected the test backup files option as there is an error de-selecting this during the actual check in version 2.2. I tested the backup without the test read and this corrected the Backup Contents File error. Owing to the nature of the fault testing may take a long time. I found out that if there are no zip files created in the backup the sessions are not recreated properly by the validate function.

Please send us the log files for this job using the Help / Bug Report function, there may be error messages in the log file during the test phase.

I would also like you to compare a restored file with the original using the Microsoft COMP (compare) command line program:

Start \ Run \ Command

COMP C:\Folder\File.ext C:\RestoredFolder\File.ext

Barry

[Jeremy]

Ok a couple of updates.

The error about the backup content file seems to have gone away without my help after running the backup again. I tried unchecking the "Test read the backup files" option, after which my first disc validated correctly. Also, I checked the disc again without closing the dialog, and now all the segments are valid. Huh? It is like the problem corrected itself. Very frustrating since I closed and reopened the application several times before, reproducing the problem every time. Now I cannot get it to happen. Maybe I rebooted or something since then? : )

I tried the test restore and comp command as you suggested, and the files seem to be restoring exactly like the originals.

In case it helps, I emailed the bug report too. Not sure what to do now since I am not having any problems. Thanks for your help!

Jeremy

[Barry]

Actually, you did draw attention to the backup file corruption and the validate not re-recreating the sessions properly if there are no zip files on the backup (probably quite rare as this has not been reported before).

Barry

[Barry]

Actually that is not fine as AISBackup will lose tack of the zip files. Is this an AISBackup Mastered DVD?

You may have to validate the last volume choosing only the correct named files to re-instate the proper name. The 'Huge' filenames should then be ignored. Is is possible you started to validate the wrong job?

I will be posting an update to the huge file problem after some more testing.

Barry

[Jeremy]

Oops sorry about that, I figured out what to do before you posted, and deleted the post explaining the problem.

I did as you stated, and now the backup is using the correct file names again. The two backup sessions that had the wrong file names are now gone from the session tab, but that is fine. This backup uses InCD packet writing (for pruning), so I deleted the bad files and re-ran the backup. It all looks good now.

I wonder if I caused this problem myself by not running the validate command when told to during the huge file backup? That one uses the integrated CD writer.

As an aside, the Session tab looks funny for the huge file backup job due to the no-zip-file problem. One of the sessions is dated 12/30/1899 for example.

In any case, I seem to be working fine now. I'm going to run a validate on the huge file backup just to be sure. Thanks again.

Jeremy

[Barry]

That's because you are in America, it says 30/12/1899 here - still wrong and has been corrected for the next beta upload.

Here is what is been fixed and tested now:

The huge file support in AISBackup has been checked out and updated as follows:

A bug was found if the backup was aborted between discs if this was mid huge file; the file was not completed. If the backup is not interrupted or the last file backed up is not a huge file everything is okay.

The huge file segment was set to 100MB because in the ‘olden day's’ CD writers were not a reliable as they are today so there was more chance of a disc read failure and part of a huge file been backed up again – making the segment size 100MB cut down on the amount of data that may have been needed to re-backup. As CD and DVD writers are more reliable, and many people are choosing to backup to external disks instead of CD / DVD the segment size of 100MB should be larger.

The segment size has therefore been increased to remaining disc / disk space subject to a maximum size of 2GB (to save messing about with media which may not support > 2GB).

You will still see small huge file segments on CD and DVD backups because AISBackup tries to squeeze as much as it can on the disc, so space remaining after compression is used for the next huge file segment.

Another historical reason for huge files was because we used a third party zip product which (for some reason) introduced errors in files > 500MB, since we now have redesigned the ‘zipping’ part of AISBackup we can handle an individual file size of up to just under 4GB (or just under 2GB on Windows 95 style systems). To this end a file nominated as a huge file will now be written to a zip file if the remaining disc / disk space is > file size and the file is < 4GB or 2GB depending on operating system. We have not introduced zip file spanning yet, but this is on the to-do list. We cannot remove huge file support in any case as AISBackup will always be able to restore from backups made in previous versions.

We will probably phase out the huge file settings in the version after 2.3 as they are becoming redundant.

Barry

[Barry]

Beta build 279 has been uploaded, this fixes the issues raised by you. The bottom line is AISBackup should not now create a huge file nless it needs to span media, or the file size is > 4GB.

http://www.aiscl.co.uk/aisbackup_beta.htm

Barry