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help with debugging failing backup

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I have been running differential backups for many months with no issues. Recently the backup gets to 15.18GB and appears to hang. Following instructions from the knowledgebase I ran VSS Doctor and ran the installation again and did a REPAIR. I also updated to the latest build.

I have followed the instructions to update the TrueImageMonitor.config to 'debug' and produced a system report.

However, I can't see anything obvious to me in the logs (using the MPV Log Viewer). But to be honest I really don't know what I am looking at.

Can someone advise as to what steps I should take to identify the issue that is causing the problem?

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Justin, welcome to these public User Forums.

We would need to see either the System Report zip file or else the log(s) for the problem backup task in order to see if there is any indication of why the backup is hanging at a specific point / size?

I would suggest that you do CHKDSK /F for both the Source and Destination drives for this backup to eliminate any disk / file system issues at work here, as that is perhaps the most likely cause.

Steve thanks a lot for getting back to me and your advice.

I have run the CHKDSK /F commands on both the source and destination drives and no errors were found.

I tried to upload the system report zip but I think there is limit to the size I am allowed to send. The zip file saved on my PC is 14MB. Is there something I need to do to reduce its size?

 

Justin, unfortunately Acronis have set a max 2MB limit for file uploads which is too low for most system report zip files.  If you have a Dropbox or OneDrive account where you could share a link to the zip file, you are welcome to send me a private message using the option shown under my name in forum posts, and I will take a look at the report contents for you.

Thanks Justin, will take a look shortly (after my dinner!).

Justin, there is no indication of disk errors shown in the system report (disks.txt) file and no indication of errors in the backup logs other than the fact that the backup has failed up to 10 times as shown by the file names in the logs.

Writing differential version to file: SERVER_USER_JUSTIN_diff_b2_s71_v1-10.tib

Files with v1-? are only created when an existing file of the same name are encountered on the destination drive.

Your Z: destination drive shows 4.5TB free space out of 7.3TB so there should not be an issue in that regard.

The logs show that the backup has been successful on previous occasions in creating 1GB backup file segments.

I am not seeing anything else in the report files to explain why the backup is not continuing as it should.

Thanks for looking at this Steve. I am not sure what to do now you can't see any issues. This backup has being running fine since September.

A few questions from me:

  1. I am presuming that there are multiple s71_v? files because it keeps failing. Should I manually delete all of these files?
  2. Is there any way to tell what filename was being processed when it hung? I am just wondering if there is something wrong with a file it is trying to read
  3. Has TI got any limit on the number of backup files it can store information about? I ask because there are 1573 files in this differential backup set.
  4. Is there any worth in changing the TrueImageMonitor.config to "debug" as documented in https://kb.acronis.com/content/60185 ? Will that yield any more info for debugging purposes?
  5. Have you any suggestions as to what I should do next?
Justin Edison wrote:

A few questions from me:

  1. I am presuming that there are multiple s71_v? files because it keeps failing. Should I manually delete all of these files?
  2. Is there any way to tell what filename was being processed when it hung? I am just wondering if there is something wrong with a file it is trying to read
  3. Has TI got any limit on the number of backup files it can store information about? I ask because there are 1573 files in this differential backup set.
  4. Is there any worth in changing the TrueImageMonitor.config to "debug" as documented in https://kb.acronis.com/content/60185 ? Will that yield any more info for debugging purposes?
  5. Have you any suggestions as to what I should do next?
  1. Yes.
  2. SERVER_USER_JUSTIN_diff_b2_s71_v1-10.tib back to v1-2 & v1.tib is the target file but there is no detail to say what source data was being processed.
  3. No limit on the number of files as far as I am aware.
  4. You can try doing so but it may not help other than making the logs larger with additional diagnostic data that can often be only understandable by Acronis development.
  5. Create a new backup task for a subset of the original source data and test whether that will work, then add to that source data and test again to see if there is any specific source data that causes the issue to surface?

Steve thanks for all the help you have given. I have worked out what the problem was but am baffled about how it has come about. I want to share the details just in case you or anybody else can explain.

I suspected that TI was hanging whilst accessing a file but, as you have pointed out, there is nothing to tell us what source file was being processed when the hang happens. After working out which files had been modified since the last successful backup I created smaller backups that included those files. After a few rounds I worked out that it was one folder containing two files that was causing TI to hang.

The big puzzle for me is that these files have been around for many years and have been backed-up almost daily by TI. What is an even bigger puzzle is that when I created a backup task containing only the folder with those two files, it worked no problem. After a lot more testing I also found that by moving the folder so it was not within a parent one, it could then be included in the full backup.

The original folder hierachy was: D:\FOLDERA\FOLDERB\FILEx  and this caused TI to hang whilst performing a full backup of the disk.

When I changed it to D:\FOLDERB\FILEx the files could be included in the full backup and it completed with no issues.

Nothing has changed with the parameters of the backup, the files included or the destination disk and directory. The only thing that has changed is the folder hierachy for the two files as described above.

It is concerning that something as random as this can cause TI to hang after it was happily working for over a year. And you are left looking for a needle in a haystack as the source disk contains over 62k files with no clue as to which one(s) TI has a problem with.

I am also worried that a similar problem could appear out of the blue just like this one did.

Have you seen anything like this before?

 

Justin, thanks for the update and for sharing your findings and conclusions.  It certainly is very strange and not something that I remember seeing before.

In some ways it would suggest a file system type issue or perhaps a security issue for either the folder structure or the actual files, but then it gets strange again that the same files can be backed up OK when moved to a shorter folder path.

But it is even weirder than that! If you leave the original folder path unchanged and just run a backup for those two files it works. It is only when those files are included in a full backup with other files and folders that TI hangs. If you then shorten the folder path for the two files then the full backup works again. It makes no sense whatsoever.

Thanks again for your help Steve, it is much appreciated.