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Originally Posted by rknichols
[SOAPBOX]
"Exact" (i.e., bit-for-bit image) copies are important for forensics and recovery of damaged filesystems. Also, if you make a copy that is not a clone of the original, all of the inodes in that copy will have a brand new ctime stamp. If you install that "copy" in place of the original, your next incremental backup will see that all the inodes have changed and will have to do extra work to determine what really needs to be backed up. (If your backup utility ignores ctime, then it could be missing some changes. For example, there's this evil beast called "prelink" that changes the content of files without any change to the size or mtime. Your rsync-based backup will totally miss those changes.)
[/SOAPBOX]
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Last time i used rsync it did bother with those all fancy backup rsync based stuff gentoo provided.
there is nothing simpler as recreating the partiton table by hand and use cp.
Are you aware of -a flag of cp command?
Quote:
-a, --archive
same as -dR --preserve=all
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Maybe I missed it here.
I do my procedure for quite a long time. Usually every 3 weeks or when I consider the data on my backups to be too old.
I have a verification of my backup. as my backup drive is put to use and the source drive is put on my shelf.
The backup is working as I use the backup drive and move the source to the shelf.
The data fragmentation is reduced. File system errors are reduced as I recreate the file system. This was an improvement over the previous backup strategy.
Bitwise copy, dd, dd-rescue, are not advised as you copy over all the errors on the drive. A bitwise copy is never suggested by any guide. This also includes fragmentation, file errors, bit swaps on the drive, other madness of the file systems or drive.
-- Backup in my own words is a full working backup, where I just put the drive in my notebook. Because of microsoft UEFI madness I have to redo the bootloader with grub-install .... This is a flaw in ASUS UEFI and microsoft. Not a flaw in my backup straegy. This was not needed wiht old bios notebooks.
I do not care for incremental backups and such. These all require a working linux. I only have one computer + one which i do not use because it does not belong to myself. So I need something to continue when the drive dies.
Also have you ever considered how long it takes install a fresh operating system. Than move back all the data from external storage? In comparision i just mount the drive and reapply the bootloader with grub-install. This is the fastest approach I know of when you need your computer and the drive is just dead.
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When you deal with dd-rescue, testdisk, you are screwed anyway
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When going to a disk that is not the same model as the original, it is likely that the way the data is represented on the disk surface is not the same
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Sorry i disagree. The user only sees what the drive reports. You do not have access to the physical layer. and what the user sees is the same.
again, I would not work on that level, as you miss out the checksums of lvm2, luks, your file system of choice. Every layer adds additional data which corrects drive errors. I doubt any of those layers works without a checksum without looking into details. Even the drive has a checksum. the reason why they made 4k sectors is to more efficency store the data and have bigger checksum blocks. bigger blocks improve the recovery rate
also with my strategy you will see cp errors every few weeks. somewhere you will see it.
i also sell any drive which is usually 2 years old. 2 years is the warranty period (or whatever you call it, that's term in law speech) in my area, the additional time which I may get from the manufacturer do not count in my point of view.