Hi folks,
I was wondering if I burn a big file on a DVD or blueray like a VHD, RAR, ZIP or 7Z would that increase the chance of lossing all the files inside the archive if the DVD \ Blueray gets scratched rather than if I burn the compressed small files directly on the media reslting in only losing a couple of files? Or is that complete nonsense?
If you have one big file (full of files), you definitely risk all of them with a scratched or unreadable portion of that DVD. If you're saving a System image (which are big), you really have no choice.
The problem with scratched/scuffed Optical discs is the damage messes up the tracks and disrupts the laser beam reading the tracks which makes them unusable. It makes no difference as to the size of the files. Compressed files are fine with many file formats but images such as .jpg are already compressed to some extent so they don't get much smaller, word processor type files do compress quite a bit.
For the damage to the files, it doesn't take much to make a file unusable when a scratch hides part of it. Corruption can also happen on drives in the computer which invokes the importance of Error Checking on a drive when getting errors. Downside to Error Checking is it can't correct problems on an Optical disc.
Do you mean do big files increase the risk of failed/faulty storage medium ?
Otherwise, of course the bigger the single storage file, the bigger the data loss irrespective of how the storage medium failed. Also bigger files can fail in themselves (irrespective of the storage medium) ... the more data, the more complex the storage algorithm
Anyway, zip files are so yesterday, they're a relic of bygone days when files had to be compressed to minimise transmission overheads when the internet was slow. Totally unnecessary now, including password protected files which can be cracked in a flash (compared with more modern encryption options)
Burn two or three identical copies of the disk, place the others in sleeves in a safe place in case the primary copy gets damaged beyond repair.
One copy of anything is not a backup. Ideally store the other copies in separate locations. Even more ideal use different media types for each backup.
You may be interested in Par files...
MultiPar announcement
Here's a fork of MultiPar. Click releases on the right. GitHub - Yutaka-Sawada/MultiPar: Parchive tool
What are PAR and PAR2 Files? - Easynews
Last edited by User2468; 06 Feb 2024 at 14:53.
Thank you very much for the clarification
The underlying question here is how to preserve your data, or how to maximize the protection of it. I will address this, but first your other questions.
1. Yes, but not necessarily. While reading (a lot), found... that some file formats, along with some ways of burning (including the type of media, sorry don't recall the details), increase the chances of recovery methods, as there is some sort of "small redundancy", not sure if MDISCS were involved, or if it was just some technique... parity? The reasons why I don't remember all the details is, because at the end of the day this didn't sound like a solid plan to me. But yes, same thing applies to certain compression file formats.
2. Yes you could loose some files, vs a whole set of them burning separately.
3. No, what you are wondering makes sense, other people thought about it, and other people discussed this at great length (somewhere else).
Now, being realistic and practical: for the capacity of DVD/BluRay, price and security, you can get WAY better results using old fashioned hard disks, even on some sort of RAID setup, or even USB memories with multiple copies.
Bonus: I used to have optical disk backups in the past, but later discovery the bad way these can stop working even without scratches, as there are spores and fungi in the air that will thrive there, or at least corrupt them even if they look basically as new. I still have some dvds (diff brands) from old backups fully working till this day, but it's mostly nostalgia, as all my data is actually stored on hard disks.
I read the following (and I'll paraphrase) in a computer magazine years ago about how to keep optical media for long periods of time.
1) Never write on the optical media. The dye/s can destroy the foil.
2)Store the optical media in a cool, dry and dark environment.
I cherish my optical media and my Pioneer Blu-ray burner capable of burning up to 50GB Blu-ray disks and M-DISCs. I fully utilize it, too. My entire Flight Simulator X install (around 55 GB) is 7Z compressed and written to a 50GB Blu-ray and stored in one of my fireproof safes. I also write certain backup data to DVD/RW disks and CD/RW disks. My website gets backed up to a Blu-ray and DVD/RW. Then those along with my other media are stored in fireproof safes. I do this to A) mitigate bit rot and B) if God forbid there's an EMP or CME from the sun, well, my data is still intact... Until mankind gets out of the stone age that is...
ALL media can and will suffer from bit rot, but with optical media if taken care of as shown from the two points above it should last many years. I have mini CDs I burned around the year 2005 with bookmarks from the old Netscape or Opera browser (don't remember) and data game saves from the PlayStation 2 using Game Shark, and the data on these mini CDs is still accessible . Why? Because these mini CDs were kept in my dresser drawer. Which was cool, dark and lacked humidity. I also did not write on them but rather on their case's.
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