ASUSTOR Community Forum

Hi,

I've a question regarding backup plan.
You can set that files which already exist on the nas are excluded from further backups. But what does "already exist" mean? Is it the filename, the filesize, the filetime?

What if a a backup process is interupted while a large file was only partly transferred?

Thanks,

David

Hi David,

Backup Plan not only check the filename but also check file size and file modified date,
to be more specific. According to the three conditions below, Backup Plan can decide to transfer the file or not

1. is the file (file name)existed on the destination
2. if file has same name, is the file size different
3. if file has same name, is the modified date different

if one of the conditions is established. the file will back up to the destination.

so if a large file was only partly transferred, Backup Plan should be able to find the file size is different,
therefore, the file will be transferred again.

cheers,

Steve

Hello Steve,

I've still got another question: If I do a further backup (some backup after the inital backup) and a file already exists on the nas how exactly does the newer copy overwrite the existing file. Is a tempory file created (like with rsync) an the old file unlinked after copying of the newer file has finished or is the the "old" file on the nas immediately deleted before the copying of the newer file starts (which wouldn't be a good solution).

Thanks
David

Hi David,

Currently our overwrite mechanism is very straightforward, for example, if we back up a file "movie.mkv" to the NAS and the file already exist in the NAS, the newer movie.mkv will overwrite the old movie.mkv immediately.

the benefit for this mechanism is
1. it won't reduce the backup speed
2. it won't occupy extra space to handle temp file.

cheers,

Steve

Thanks Steve,

however, this solution isn't a very safe one. If the backup process is interrupted both the old file and the new file are corrupt on the NAS. Not very satisfying.

David

Hi David,

We will think how to improve this , I've put it in our feature request list
thank you for your suggestion.

br.

Steve

Hi Steve@AST

It would be great if the backup app also has some advance backup functions such as daily/weekly/monthly backup folder creation, time stamp backup folder creation, volume shadow copy, compression, full/incremental/differential backup job option, etc. Any plan to develop these functions in the near future ?

Thanks

Best Regards,
Astro