Thomas A. Anderson writes:
Thanks Reco, yeah that RAID6 looks pretty robust. I will read more about it in the future. When I type cat /proc/mdstat, I get: Personalities: unused devices: <none>
Is that all there is? Because to me this means: RAID kernel driver loaded but no arrays running whatsoever. This state would also mean "zero redundancy"!
Here, it looks as follows:
~~~
$ cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md1 : active (auto-read-only) raid1 nvme1n1p3[0] nvme0n1p3[1]
127933440 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md0 : active raid1 nvme1n1p2[0] nvme0n1p2[1]
379868160 blocks super 1.2 [2/2] [UU]
bitmap: 0/3 pages [0KB], 65536KB chunk
unused devices: <none>
~~~
Note the presence of different `md` devices and `UU` showing that two RAID1
mirrors are active each with two disks (actually: partitions on the same two
disks) present.
Thanks Deloptes, the Borg backup looks very promising and I think it might actually best fit my needs. I will check it out!
At the moment, borg seems to be among the best "complex" backup tools -- i.e. tools that store data in their own format to achieve an additional benefit. If you like to pull a HDD and use it with another computer, a simpler approach like "rsync" or "tar" may also work well.
[...]
Once I can get anything off one of these two drives, I will then switch my current setup to 1 drive (8TB), with an attached 8TB drive that will be be backup --weekly, or whatever.
Consider making this "daily" -- tools like borg allow you to keep copies of one week history without needing much additional disk space (depending on how much your data changes, that is).
[...] In your original post you wrote:
It is only now that I wonder if I am even using RAID1 properly? In other words, now that I try to access data on these two original drives on another system, I am unable to. I assume it's possible (albeit doesn't seem intuitively simple -- at least for me), makes me wonder if it's enen supposed to be used like this. I had assumed I could swap the drive out, and access the data (like a normal drive), but that doesn't seem to be the case.
What did you actually want to do? Just check whether the data is there? In these cases, a proper backup tool like Borg will allow that better. RAID is always picky about devices that are "temporarily absent" because what if data on just one of the devices changes? It could cause inconsistency and thus often requires explicit manual intervention to resolve (let the user decide which data to consider the "proper" copy). Hence, it is a sensible default for RAID tools to _not_ automatically enable/mount attached disks [unless all of the RAID's members are present].
If you are trying to move data between systems rather than just testing your backup, then there are many alternatives to consider (including, but not limited to rsync, network file systems, tar files).
HTH Linux-Fan öö
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