Long term backup

[NoWinBob]

Just wondering:I am using a 2tb external  HDD (ext4) in a standard external enclosure for my main backup of data files.I am wondering about file degradation of files that aren' t accessed very often,if ever.I have copied files from the backup to various computers,but there are some that rarely if ever get accessed.Is ther a utility I can run to check the integrity of the backup?I run Mint18.3 on my main machine and Peppermoint 9 on my (slower) laptop.

[leon.p]

Just wondering:I am using a 2tb external  HDD (ext4) in a standard external enclosure for my main backup of data files.I am wondering about file degradation of files that aren' t accessed very often,if ever.I have copied files from the backup to various computers,but there are some that rarely if ever get accessed.Is ther a utility I can run to check the integrity of the backup?I run Mint18.3 on my main machine and Peppermoint 9 on my (slower) laptop.

You could write down the checksum of the file and if you are unsure whether
the backup is degrated, calculate the checksum again and then compare.

[NoWinBob]

Just wondering:I am using a 2tb external  HDD (ext4) in a standard external enclosure for my main backup of data files.I am wondering about file degradation of files that aren' t accessed very often,if ever.I have copied files from the backup to various computers,but there are some that rarely if ever get accessed.Is ther a utility I can run to check the integrity of the backup?I run Mint18.3 on my main machine and Peppermoint 9 on my (slower) laptop.

You could write the checksum of the file and if you are unsure whether
the backup is degrated, calculate the checksum again and then compare.

Thanks Leon.

[henrysay]

Just wondering:I am using a 2tb external  HDD (ext4) in a standard external enclosure for my main backup of data files.I am wondering about file degradation of files that aren' t accessed very often,if ever.I have copied files from the backup to various computers,but there are some that rarely ->FileZilla UC Browser Rufus if ever get accessed.Is ther a utility I can run to check the integrity of the backup?I run Mint18.3 on my main machine and Peppermoint 9 on my (slower) laptop.

You could write the checksum of the file and if you are unsure whether
the backup is degrated, calculate the checksum again and then compare.

Thanks Leon.

I am wondering about file degradation of files that aren' t accessed very often,if ever.I have copied files from the backup to various computers,but there are some that rarely if ever get accessed.Is ther a utility I can run to check the integrity of the backup?I run Mint18.3 on my main machine and Peppermoint 9 on my (slower) laptop. 

[Joel920]

Anything mechanical breaks, you also need at least two backups and three is preferred. One of those backups should be off site (in case of a fire). Rotate the disks around so you are only one backup behind.

[leon.p]

Anything mechanical breaks.

Indeed.

The absolute best backup method I have found (which is still doable
without expensive lab-equipment) is simply printing it out. Stored
in a water and fire resitant location, paper will last considerably
longer than any currenty wide-spread storage medium.

You can simply split all your data into equal chunks and convert them
into QR-Codes, which you then print. To get your data back onto your
computer, simply scan the codes to get the raw data, which you then
combine again.

That is easy on Linux: Simply create a tar-archive with 'tar', which
you could even compress. Then use 'split' and 'qrencode' to generate
the codes. To scan them you can use 'zbarcam' and then use 'cat' to
combine the chunks back into the tar-archive.

[Lady Fitzgerald]

Anything mechanical breaks.

Indeed.

The absolute best backup method I have found (which is still doable
without expensive lab-equipment) is simply printing it out. Stored
in a water and fire resitant location, paper will last considerably
longer than any currenty wide-spread storage medium.

You can simply split all your data into equal chunks and convert them
into QR-Codes, which you then print. To get your data back onto your
computer, simply scan the codes to get the raw data, which you then
combine again.

That is easy on Linux: Simply create a tar-archive with 'tar', which
you could even compress. Then use 'split' and 'qrencode' to generate
the codes. To scan them you can use 'zbarcam' and then use 'cat' to
combine the chunks back into the tar-archive.

Hmmm. How well would that work for videos? Flip pages? If one has a lot of data (such as my 10TB), that would take a large truckload of paper. Searching for specific data in that pile would take forever. Getting that much paper is also hard on trees.

Backups can't be static. One has to actively maintain them to ensure corruption doesn't creep in and the media they are stored on is kept up to date so it doesn't become obsolete and, thus, irrecoverable.

[leon.p]

Hmmm. How well would that work for videos? Flip pages? If one has a lot of data (such as my 10TB), that would take a large truckload of paper. Searching for specific data in that pile would take forever. Getting that much paper is also hard on trees.

Backups can't be static. One has to actively maintain them to ensure corruption doesn't creep in and the media they are stored on is kept up to date so it doesn't become obsolete and, thus, irrecoverable.

It is obviously not very practical for large amounts of data.

However it could be useful to backup extremely important data.
You could also sort the paper into folders, so you know what is
on them.

Appearently, one can store up to a maximum of 23648 bits in a single
QR-Code, although the thing would be quite large (177 by 177 "modules",
as the blocks seem to be called). That is slightly below 3 kB.

I am curious, so I calculated it (most numbers are rounded):

My favourite song (Reason to Belive, from Arch Enemy) is about 32 MB large
stored as FLAC. That would need about 10827 QR-Codes. If I convert it to
OGG-Vorbis, it is only about 3.76 MB large, which would require about 1250
QR-Codes. So it is definitely not suited to store audio in a remotely high
quality.

However, the picture of the album cover, a jpg, 1000 by 100 pixel, is only
269 kB large, needing around 90 QR-Codes, which is way saner. If we put
two QR-Codes on a piece of paper, and also two on its back, you'd need
about 23 pieces of paper. Obviously printing out the picutre would only need
a single piece of paper, but scanning that back in will have negative effects
on the quality, while scanning the QR-Codes and putting the split data back
into a picture will lead to a bit to bit exact copy of the picture,
therefore being an nice interesting option for longterm backups of
small-ish pictures with a relatively low risk of quality-loss. And since
you get the exact same file back, you could even use check-sums to see if
the data has corrupted.

---

Historically, paper is one of the most reliable storage media, loosing
only to things like carved stone. Having a way to put any possible
data onto paper (and theoretically even into stone) is an interesting idea
to make the jobs of future archeologists easier and more fun.

[NoWinBob]

Hmmm. How well would that work for videos? Flip pages? If one has a lot of data (such as my 10TB), that would take a large truckload of paper. Searching for specific data in that pile would take forever. Getting that much paper is also hard on trees.

Backups can't be static. One has to actively maintain them to ensure corruption doesn't creep in and the media they are stored on is kept up to date so it doesn't become obsolete and, thus, irrecoverable.

It is obviously not very practical for large amounts of data.

However it could be useful to backup extremely important data.
You could also sort the paper into folders, so you know what is
on them.

Appearently, one can store up to a maximum of 23648 bits in a single
QR-Code, although the thing would be quite large (177 by 177 "modules",
as the blocks seem to be called). That is slightly below 3 kB.

I am curious, so I calculated it (most numbers are rounded):

My favourite song (Reason to Belive, from Arch Enemy) is about 32 MB large
stored as FLAC. That would need about 10827 QR-Codes. If I convert it to
OGG-Vorbis, it is only about 3.76 MB large, which would require about 1250
QR-Codes. So it is definitely not suited to store audio in a remotely high
quality.

However, the picture of the album cover, a jpg, 1000 by 100 pixel, is only
269 kB large, needing around 90 QR-Codes, which is way saner. If we put
two QR-Codes on a piece of paper, and also two on its back, you'd need
about 23 pieces of paper. Obviously printing out the picutre would only need
a single piece of paper, but scanning that back in will have negative effects
on the quality, while scanning the QR-Codes and putting the split data back
into a picture will lead to a bit to bit exact copy of the picture,
therefore being an nice interesting option for longterm backups of
small-ish pictures with a relatively low risk of quality-loss. And since
you get the exact same file back, you could even use check-sums to see if
the data has corrupted.

---

Historically, paper is one of the most reliable storage media, loosing
only to things like carved stone. Having a way to put any possible
data onto paper (and theoretically even into stone) is an interesting idea
to make the jobs of future archeologists easier and more fun.

Yea,how do I print over a TB of video?My strategy so far is to have multiple copies of stuff I really care about,plus one large (2TB) external HDD for everything.Since I recently had a fire in my house,I am trying to figure out how to keep another copy in the detached garage.I guess a HDD in a moisture proof container,and see if it can survive -30 degree winter weather in Canada.No its not that cold all the time;usually only a few days at a time.

[spudnuts]

I would suggest an insulated container if keeping it in the garage because yes it will still change temperature but the change will be slowed down so less chance of the drive warping/condensating and causing damage to it.