Earlier quoted context omitted.
> Currently, I just dd my block devices That's actually not a good idea at all. It's very fragile, the slightest problem and you may lose the entire backup. Silent corruption may get backed up for months and you won't notice until it's too late. Doing a restore means having space for the full file, just to restore a single small file. If you don't know when your file changed you may have to do that multiple times ins…
Why is dd fragile? I mean, yes doing so while the filesystem is mounted is like Russian Roulette, but if the filesystem is unmounted? I see that it isn't very efficient, but I never had any problems with reliability. Silent corruption might actually be a problem, but that is something you won't solve by backing up files and directories instead of block devices. After all, a block devices backup just contains more inf…
considering in many cases you want to copy live files, you have to copy them to place you can unmount, so now you have 2 problems
if you dont gzip the dd you risk pure cosmic microwave background bitflips and no checksums, and they can corrupt superblocks and etc
if you gzip it (to have crc sums) you cant restore partial files from it so easily unless you use squashfs and significantly complicate the process
so tar and gzip is more robust (compared to the dd) just because of the crc (of gzip not of tar), size and portability