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I have had bad backup copies in the past (and I have no idea when or how it happened)
This is the danger with untested backups. (Not just verify)
As I said earlier
I see it a few times a year, people who think their backup is good because it verifies but when it comes to recovering it, not so much. -
As I said earlier
I see it a few times a year, people who think their backup is good because it verifies but when it comes to recovering it, not so much.
Why would this happen? Is the verify no good? I believe Teracopy does a bit wise test, it takes just as long to test as it does to copy the files. The files are not encrypted, they are the same as the original.
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As I said earlier
I see it a few times a year, people who think their backup is good because it verifies but when it comes to recovering it, not so much.
Why would this happen? Is the verify no good? I believe Teracopy does a bit wise test, it takes just as long to test as it does to copy the files. The files are not encrypted, they are the same as the original.
May I suggest an application called Arq backup. It runs in the background, backs up to Amazon's cloud storage, costs very little per month in storage, includes versioning, can also simultaneously store the same backups locally on a network drive or other local storage.
Sent from my Nexus 7 using Tapatalk
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LTO tape :-D
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I see 2 mayor classes of "Backup"
1) the connected, automatic backup, with hardware at the same address.
2) the manually plugged-in and started, with multiple unconnected hardware stored in a safe somewhere else.
Why not a hybrid? Stick a raspberry pi or similar computer with an external drive at a friend or relative's house plugged into their network, and sync your local backup to that system automatically. It's online, automatic, and remote. This is stupid easy to do with rsync and an SSH tunnel if you run Linux or Mac, or even with Cygwin on Windows.
What you describe is a solution that falls under category 1.
Not protected against overvoltage, y2018 viruses, soft bugs, house fire, EMP pulses, floods, NSA, DEA and Navy Seals. -
I see 2 mayor classes of "Backup"
1) the connected, automatic backup, with hardware at the same address.
2) the manually plugged-in and started, with multiple unconnected hardware stored in a safe somewhere else.
Why not a hybrid? Stick a raspberry pi or similar computer with an external drive at a friend or relative's house plugged into their network, and sync your local backup to that system automatically. It's online, automatic, and remote. This is stupid easy to do with rsync and an SSH tunnel if you run Linux or Mac, or even with Cygwin on Windows.
What you describe is a solution that falls under category 1.
Not protected against overvoltage, y2018 viruses, soft bugs, house fire, EMP pulses, floods, NSA, DEA and Navy Seals.
Except that it is...at least against most of those. It's not at your local address, it's remote, so it's immune to any event that's isolated to your location (voltage, fire, weather, etc). It's no more susceptible to viruses, bugs, or the government than your "category 2" is either.
Your remote backup doesn't have to be immune to everything, it only has to be immune to the specific event that took out your system and your primary backup. You don't have to get very far away or isolated for that to be the case. -
As I said earlier
I see it a few times a year, people who think their backup is good because it verifies but when it comes to recovering it, not so much.
Why would this happen? Is the verify no good? I believe Teracopy does a bit wise test, it takes just as long to test as it does to copy the files. The files are not encrypted, they are the same as the original.
It depends on what you're backing up, how it's backed up, where and how the verify happens and a multitude of other things but the only way to truly verify a backup is to restore and then sanity check the data.
Teracopy sounds like it does a reasonable job but even then you only get back what you back up, if the original is garbage it will have no way of telling.
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https://en.wikipedia.org/wiki/S.M.A.R.T.
https://en.wikipedia.org/wiki/Data_degradation
As I said earlier
I see it a few times a year, people who think their backup is good because it verifies but when it comes to recovering it, not so much.
Why would this happen? Is the verify no good? I believe Teracopy does a bit wise test, it takes just as long to test as it does to copy the files. The files are not encrypted, they are the same as the original.
A simple example
1. from drive 1, read file in to memory1
2. From memory1 write file to drive 2.
3. From drive 2, read file in to memory2
4. Compare memory1 to memory2 for match
This is fine until
1a. Memory1 changes and computer does not use ECC memory Or Memory1 is bad.
2 writes bad file, 3 reads bad file and 4 verifies bad file matches bad file.
a change to
1. from drive 1, read file in to memory1
2. From memory1 write file to drive 2.
3. From drive 2, read file in to memory2
3a. from drive 1, read file in to memory3
4. Compare memory3 to memory2 for match
This change would have catch to catch this.
Some here will say small chance( true) but memory errors do happen.
You are still assuming that to/from disk surface to/from memory is perfect.
The above links describe other errors that happen.
What I am reading is making many copies of a file with unknown status and no easy way for computer to know if file is good or bad.
https://en.wikipedia.org/wiki/Checksum
A file checksum is one way that can help.
It also sounds like you want an archive more then a backup and be able to create many copies of the archive.