On 2018-01-13 02:27, Anton Aylward wrote:
On 12/01/18 03:50 PM, Carlos E. R. wrote:
I have created ISOs on the CLI years ago, it is not that difficult. I can help with that part. The dificulty is adjusting the size. I have no idea how to split and span to several DVDs.
As far as I can make out there seems to be a few different approaches to all this.
On the one hand there are the 'snapshot management' types such as dev-dup and backintime that need to maintain a database and really are a dis-to-disk(-to-offline) so that the snapshots are easily recoverable
Need a big disk for destination. Can't use DVDs.
Then there are the ones that don't keep the database, or at best rely one the label on the DVD, written or electronic, and are probably event drive, such as a completion of a particular project and hence archiving all its working papers and reports.
There *may* be some way to logically organise this archiving, for example 'monthly' as the project progresses. That takes the pressure off the 'spanning multiple DVDs' issue.
They don't need the database of the individual files in the same way.
Once you do get into spanning multiple DVDs then you get into two issues. The decision of where to split goes hand-in-hand with the decision of what files to put on each DVD most efficiently (or optimally) -- the 'packing problem' which is at the very least NP-hard and quite probably NP-complete https://en.wikipedia.org/wiki/Bin_packing_problem https://en.wikipedia.org/wiki/Knapsack_problem#Multiple_knapsack_problem https://en.wikipedia.org/wiki/Packing_problems
The second issue is that you need a global index of what is on each DVD. Either you have to pre-compute the "bin packing" and ahead of time and record the index on each DVD as a 'header' that says 'it's here or its on the other one' or the index has to be external.
I can't say I like any of this.
What we need is a K3B that is super-super smart, since I really don't fancy trying to all this with shell script.
I'm sleepy. Let me say that the best backup program I have ever used was PCtools Backup, before the 90's. For MsDOS. I used it with floppies. It was so fast that I barely had time to write the label on the floppies. It formatted them on the go. It could verify them. It wrote the index of files on the last floppy, and on a file on the hard disk. A file could span more than one floppy. It did compression on the fly, and used forward error recovery (it could recover bad sectors). It did full backup or incremental writing changed files automatically, taking note of deleted files too. I could define a list of directories and files to include or exclude. I miss it. I don't understand how thirty years later there is nothing similar for DVDs on Linux. Or any other media.
What I envision is going through this list one by one:
Well, yes, there is that. Let me know ....
In time. It is large. I have done nothing tonight. I can say that the list includes dead projects. -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)