Acronis defeats the whole purpose of archiving, or am I wrong?

I was doing incremental backups for the last three month, and now when I needed it most, Acronis came up with a message that it can not validate my backup archive. Low and behold, I tried to make another backup of my current windows installation disk and once again, Acronis says the backup is corrupt right after creation of the backup. I have ZERO idea of what is going on and I am really MAD.
Few additional info:-
Backup was always created outside Windowz environment, that is teh PC was booted from restoration CD. The first full backup was verified rigth after creation, later incremental backups were not. Latest fullbackup was verified right after creation.
Backups are stored from day 1, in an external firewire hard drive. So far, I have not seen any sign of data corruption any any other files located in the same drive.
What to do now?

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

Sounds like something was working properly and now it isn't since you did validate the full archive after creating.

The way Acronis validates archives is by creating a checksum when the archive is created and including it in the archive file. When you validate you read the file and do the same checksum calculation and the number you get should agree with the one stored with the archive. The kicker is that it must be exact to the extent that one bit wrong in a multi-gigabyte archive will cause the archive to be declared corrupt.

The easiest thing to try first is to run chkdsk X: /r on all your partitions including the firewire drive. Substitute X for the drive letter of the partition being tested.

Bad RAM can cause corruption messages. Download Memtest86+ version 1.7 from www.memtest.org and let it run overnight. Be sure you get the PLUS memtest, V1.7!

If you have space, make an archive to an internal drive. You can, if necessary and if you have the space, make an image of C onto C if you don't have another partition or drive. You will get a warning message but ignore it. See if you can validate this archive. As far as disk drives go, an internal drive is usually the least problematic.

Let us know what this uncovers, if anything.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

I will definitely give it a try with memtest. However, I hardly had any problem with rest of the PC.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

That is not uncommon. If you have a data file such as a jpg picture loaded into memory and there is a bad RAM location there is a good chance it would cause no problem and you wouldn't even notice the bad area.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

I have recently experienced the same problem as Sensia - I evaluated TI Home 10 and it worked flawlessly for that period - I did full restore from backups, all without problem. So I purchased and ran it on a desktop system for three months since December. Just recently it started saying it could not validate my backups. I ignored the problem for a while since I was also using Retrospect to do a remote backup and it was working fine.

Today I did some more investigation - did a chkdsk /f/r/x on both source and target drives and retried. Still could not validate -says archive is corrupt. Now I started reading the forum and seeing all the problems people have reported and I'm somewhat alarmed - I'd already started recommending this to my friends and SMB clients (I fix computers part time), now I'm not so sure. I'm going to run a memtest on the machine that is failing tomorrow, and experiment with no compression - but I just reran a validate (instead of doing as part of the scheduled backup) and it passed. The backup is to an external USB drive so obviously bus I/O errors are suspect causes too, but as I said this backup had been running flawlessly for at least a couple of months.

As I say, I'm willing to blame hardware but kind of disappointed that my whole backup could be junk because of a 1 bit error - does a non-validating archive prevent me doing anything like restore? I haven't tried it (and really don't want to) - perhaps you should give an option to ignore it, or do a different checksum algorithm so that a 1 bit error doesn't trash the entire backup.

It would also be nice if your help/doc in the program give more info on what to do if you get such a problem. Having to learn about memtest and such from the forum is not a good experience...

Other than that... ehemm... I do think this product has great potential, compared to Retrospect using it is a breeze - although it did take a while to figure out how backup destinations interact with incremental/differentials. Once I realized a "backup location" was effectively what Retrospect and others call a backup set it was plain sailing. Perhaps you should make it more obvious one should really choose a backup location in the UI instead of just listing them in the middle of all the regular drive/folder destinations. It should be more like "Choose/create your backup location" with an advanced tab to go browse for a regular folder destination.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

Hello WhoGrant,

It's often the case that TI can "Mount" an image that's been declared corrupt so that you can copy your important files from it.

Regards

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

For the record I'm not doing an incremental like the other user - I do a differential with a weekly cycle so never have more than 2 backup files to rely on, or one if I can do with a week old copy of my system.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

Thanks, I hope this is true when I really need it - it would be nice if there was a way to distinguish a "checksum failed" error from a "its really corrupt" - maybe mount and then do a chkdsk? Fortunately the corruption messages have occurred when there wasn't a need to use them.

Last week was the first time the corruption had stopped the nightly scheduled task - previously I'd only seen it when doing a manual validation (just before I went on vacation to make sure everything was okay - nice surprise!). At least I get a nice email to alert me to the problem - unlike Windows ntbackup!

I will post the result of memtest when I have a chance to run it.

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

Hi again WhoGrant,

Can we take it that you retain all differentials associated with a particular full backup? Whilst you can restore using the original Full image and any Differential associated with it, you need all the associated Differentials in order to carry out a validation.

Regards

 

I maybe missing something here, but the only time I have ever had a corrupted image is when I was burning them to DVD's. I have been using TI for almost 3 years. Also the statement that "3 months incrementals is pushing it" I disagree. The problem is verifying the latest backup (Either FULL or INCREMENTAL) at the time of backup completion. One should perform this function everytime you backup. This will save you alot of grief when you really need to restore your system. Also Before doing any backup, you should always do a CHKDSK. The point is "why would you want to backup BAD data ?" This is what you get if you don't perform a CHKDSK B4 backing up.

Just my 2 cents worth.

Storage_man

 

Re: Acronis defeats the whoel purpose of archiving, or am I wrong?

One difficulty is knowing if it was really 1 bit or a bunch of bytes or whether they are in 1 sector or spread out over a bunch of sectors. On the other side of the coin, it is telling you there is something wrong with your system in that the archive cannot be read or possibly written reliably. In other words, there is a problem that needs to be rectified - a properly operating machine doesn't have the problem.

As Menorcaman pointed out, you may well be able to mount the image and recover files.

Storage_man is correct about the wisdom of doing a chkdsk before backing up. I suspect that some of the retore issues (not validation ones) are caused by screwed-up disk structures.

I also agree with validating archives after they are done; if nothing else they confirm noting has gone wonky with your hardware since the last restore. However, XPilot's method of immediately restoring to another disk and putting it into service does eliminate the need for validation and is an even more reliable method. Just to create and store without a validate, IMO, is risky. Also, new users should ensure they can validate with the TI rescue CD even if they don't want to do a test restore on a spare HD. I think this is one of the reasons for the reasoning that the validation process produces false positives - the validation is done under Windows but it is the Linux environment and Linux version of TI that has to run to recover the active partition - and this just isn't the same thing.

A chain of validated incrementals should not be a problem but there is one weakness in a long chain - if one incremental goes bad for any reason then all the later ones are useless. A series of Full images doesn't have this problem but at the expense of time and space.