How to check if a backup is valid
Hey, I am testing Acronis TI for Mac and So far it works great.
However as in the past I had problems with corrupted Time Machine Backups I am careful and I would like to check if the backups created by ATI are ok. How can I do that? I did not find a way to verify the backups.
Thanks for a hint.
Personally, I don't recommend you put all your eggs in one basket.
Having a mix of Acronis and TimeMachine gives you multiple options to recover from.
Likewise though, if you use 1 backup location for both products and that backup location becomes damaged, corrupted, stolen, etc. you lose everything that way too.
Mabye use time machine to one location and Acronis to a second location to give yourself some diversity and recovery options?
Thank you guys for your suggestions.
I have used Time Machine for many years, more or less without problems, mostly over Wifi. However for some months the disk image on my NAS became corrupted many times and I had to start new backups from scratch. I have invested in a faster Wifi network and also a better NAS, but the problems remain. So I was hoping that Acronis was a more reliable solution. In order to check that I have asked my question above, but it seems there is not really a way to verify backups easily. Just browsing backups or restoring some files does not give me enough information to trust the whole backup history.
There's no way to know what the corruption is coming from. I honestly suspect only using wifi may be the culprit. Even the best wireless nework can have dropouts, interference, etc. Backups can be large/long and doing something like that over wireless probably just isn't reliable and may be the real culprit.
Acronis is good. Time Machine is pretty good too - both have served me well. I just wouldn't rely on any 1 backup or any 1 backup location. Perhaps you could time machine to the NAS since it does it's thing regulary (hourly) and look to use Acronis (or anything else you want) to a local USB drive from time to time to supplement one with the other.
One backup, regardless of the backup product/solution, just isn't adequate. Please take a look at the 3-2-1 backup strategy. It is the baseline for IT backups and should be for home backups too.
It's not just Acronis that recommends this either, it's industry-wide. Google 3-2-1 backup strategy.
Thank you all for your comments.
Well it turns out that my prudence was a good idea. Here is why:
Yesterday I made another backup with ATI to my Nas over Wifi. During the backup I disabled Wifi and enabled again, as closing the lid of the Mac or loosing the Wifi signal is something that happens during normal usage. So this was kind of a "stress test". ATI paused and then continued the backups, and it seemed everything was ok.
Then I followed your suggestions to check the backup on my NAS by browsing through it, and recovering some files and a folder. This all works fine.
Then I tried a complete restore. I rebooted my Mac with the boot media created by ATI before, I deleted the build in hard drive partition and tried to do a full restore from my NAS. It started fine, then after some minutes I got an error saying that some files cannot be read and the restore stopped.
Boom! So what first looked like a working, reliable backup turned out to be in fact a corrupt backup, I am not able to do a restore, and if this would have been my only backup I would have been screwed.
Since ATI is not able to verify the integrity of a backup, it seems it is just random if a restore backup will work or not, there is no way to tell before.
So its clear that ATI wont work for me. Reliabilty is the no. 1 criteria of a backup program, and exactly here it fails.
Thanks again for your support and maybe I will have a look at ATI again when it is has become more mature, for now I will look somewhere else.
I have used Time Machine for many years, more or less without problems, mostly over Wifi. However for some months the disk image on my NAS became corrupted many times and I had to start new backups from scratch. I have invested in a faster Wifi network and also a better NAS, but the problems remain.
tried to do a full restore from my NAS. It started fine, then after some minutes I got an error saying that some files cannot be read and the restore stopped
I think you're chasing a ghost. There's a reason backups are becoming corrupted - Time Machine ones too. I'd guess that wifi is really the culprit. Have you tried connecting directly with an Ethernet cable for either your Acronis or Time Machine recovery? All you've proved so far is that there's a problem occuring, but not where the problem is stemming from. My gut says it's wireless as this is a common, recurring problem for those who want to restore large data sets over wifi... where even the best signals and speed are still susceptible to interference and more likely to cause issues when connections are disrupted.
But I think the main point here is that the backup program should tell us that the backup is invalid so it can be corrected. The absolute worse thing that could happen is to have a crash and only during the full restore find out then that your backup file is currupt. Somewhat dissappointed that Acronis doesn't seem to be very robust ...
Do you guys know of a util or command line method to run against a tib file to check if its valid and not currupt?
BryanD, how do you define what is corrupt or not?
Acronis can do a Validation of the backup files it is creating and does this by calculating a checksum for the data written to the backup file and comparing this to the checksum value stored within the file to ensure that nothing has changed since the file was created.
This is not a guarantee that the data being backed up was not already corrupt or that corruption didn't occur in the transfer of data to the storage device, though I would expect that to be picked up if the checksum is calculated based on the data before transmission.
There is no command line / utility to check a .tib file other than the validation process - the only other method is to open or mount the .tib file and attempt to either restore random files / folders or to restore the whole backup to a spare drive etc.
Hi Steve -
Thanks for the info. I usually see an option to "validate" a backup file but that seems to be missing from the Mac Client. By validate, I guess the client just goes through the restore process without restoring files .... (i.e. think of it as validating a tar file or zip file ... I've seen times where I'm unzipping a file and it gets half-way through and says the file is corrupt). Hopefully Acronis might add in the near future.
Bryan, there was an earlier update from Ekaterina on 04/04/17 where she stated:
Currently, validation feature is only available in the Windows version of Acronis True Image 2017. We've documented this a a feature request for future Mac builds, however, no ETA for now.
The Acronis validation function in Windows doesn't do as you guess (goes through the restore process without restoring files) but as mentioned previously, it compares the checksum stored in the file when created with the checksum recalculated for the file, which can only tell you that nothing has changed but not that the original data was free from corruption.