Image copies placed by other means on two additional media - verification
Image copies placed by other means on two additional media - verification
Acronis TI Home 2009
Scheduled imaging by Acronis TI places the images/backups in creation on a special
partition of the disk where system partition is placed as well.
As soon as the imaging process is complete, the image is been copied by other means
(non-TI means) onto two other media, NAS and DVD.
It doesn't seem to be possible to perform the image verification of image copy placed
on NAS and DVD using TI. Is that right ?
I am not familiar with 2009. Do you have a context menu when you right click on the archive files you want to validate? IN 2011 there is an "archive" context menu, with mount, restore, validate as sub-options.
Thanks for info.
Yes, the "verify" option on tib's context menu is available also with 2009. I guess for verification all base and increments/differentials must be placed on the same medium.
Is this true?
If I always keep the base image on one DVD disc and the diff image on second DVD disc, the verification will not be possible, except for I will copy both images to hdd.
Is this true?
Actually, every OS as soon as running it is a living enemy.
Every minute it can generate logs, update cache, do others. Not to mention the run and usage of applications.
I wonder how is the verification possible, because after some minutes of run the original does not more reflect the imaged state to 100%.
True Image has to have all the required archive files in one folder to validate on HD.
I don't use DVDs but you might try putting in the differential DVD and see if it will ask for the full component. It may or may not work.
You are correct about the OS changing files all the time.
TI and and other live imaging backup programs do not do a validation by comparing the archive's data with the original source because the source has changed. TI writes a checksum into the file for every 256K bytes of data. This amounts to 4000 checksums per gigabyte. When the archive is validated the data is read into RAM and the checksums are recalculated and compared to the ones written into the archive when it was created. They all must agree perfectly or the archive is declared corrupt. The amount of data checked and the high speed also results in a workout of the disk system and RAM which means TI may uncover hardware issues that are not normally seen in regular PC use.
This method also allows you to validate the archive on a different PC than the one used to create it.
Chrizio,
I didn't try to run validations when the different elements of a chain are on different media, but I did run validations when these elements are on different mounted disks.
ATI has a database that tracks where each component of a chain has been stored (name and location). For example I made a full backup on one disk and I continued the incrementals on another disk. Validation passed. At one point, I changed the full backup file name manually for testing, and ran a validation. ATI asked me to point to the missing file, and validation passed with the renamed full.
I expect that in the case you are using DVDs, ATI will ask you to put the corresponding DVDs in order to continue the validation.
1.One DVD disc with full image and one with differential.
Do you think if I start the verification with disc containing differential image on it will I be asked by ATI for changing the DVD disc one time only?
2.Regarding the verification of checksum for 256kB long blocks of data. Some blocks of the same file might have changed, some blocks might to be created in the meantime, rest of blocks must be unchanged since image generation.
Those appeared newly must be no problem for image verification process, these are just new data.
But those where checksum changed (consider cache, temp, or log files), they can cause the validation to fail. Anyhow they can had changed on controlled manner, cache, temp, logs.
How does the verification deal with such blocks?
The verification is only internal to the archive. It doesn't compare with the data on disk. You can take a TIB file and have it verified on another computer all by itself.
I conclude from all your statements the validation of differentials or incrementals should not ask for full backup. Because the check sums are rather calculated from files included in the differential or incremental and the references to full made in diff/increm. But not from files included in the full self.
Am I right?
Not quite. The validation will work its way through the entire chain for archives, but without comparing with the data on disk. So this is still an ATI internal process: the validation uses the information from the ATI database and the information in the TIB files to determine which TIB files comprise a complete archive (full + partials) and then does the internal checks within the TIB files. In other words, ATI validates the integrity of the backup, not the fidelity to the original data.