Secondary backup on external SSD

Support
#1

Hello everyone,
Thanks to the help from the people in this forum I managed to create my backup using STORJ and duplicacy CLI on my windows PC. After that, I tried restoring a few files to a laptop I had lying around and everything seemed to be working fine.
From this point, I want to add a second backup on an M2 SSD that I have on an USB C external case; and I have a few questions.
First of all, and maybe it is a bit of a stupid question, I guess the storage name and snapshot id are pretty self explanatory, but storage url? Since it is local would it be F:/ backup for example? Or is there something else I should take into account here?

From what I’ve read the best way to do it would be using the copy command. Before that I’m guessing that I should add the SSD using -e -c 32M -max 64M, as I used on the STORJ one. There is also the option of doing -copy default, but don’t know if there is any reason to do it one way over the other.

After that I should copy -to newstoragename -threads 15 -download-threads 15. Would that be enough? When are snapshots ids actually used? Would I have the snapshots id from default just copied to newstoragename?

Anything else I should consider? My knowledge here is very limited and, as before, I rather be sure of what I’m doing before breaking something up.

Thanks in advance!

#2

Yes, pretty much. URL stands for “uniform resource locator”. In case of filesystem on windows f:/ is a valid url.

It isn’t. If you copy from storj you will incur egress cost.

You don’t have to. But if you plan to copy between the two locations, you shall add the second one as copy-compatible with the first.

  • SSD data retention when powered off can be very poor. When powered, it constantly runs read patrol and cell refresh/repair workers.
  • SSD failures during writing new data can result in data corruption of old data, due to copy-on-write implementation.
  • consider enabling erasure coding in duplicacy if you backup to a single drive
  • format the SSD with 4K (or 8k) sector size. Most modern SSDs, and especially Samsung EVO, lie about sector size. As a result, performance and endurance plummets.
#3

As usual, thanks for such detailed answer!

I though of that, but besides the initial copy if should not be quite a lot since I’m not backing a ton of data.
Now that I think of it, the disadvantage of just making two independent copies would be that I would use twice the resources to make the copies, which would not be much for the same reason.
Maybe it would be just easier to go that way.

In case of finally making two different copies I guess the encryption key would be a new one, and chunk size would not be important since It is local and the 32M and 64M were specifically for STORJ. Or would be an “optimum” chunk size in this case?

I knew about that, my idea was to connect it weekly for backup and to prevent it from being powered off for long periods of time. From what you say it might not be enough. I could toss it on one of the free slots of my MOBO and have it always connected to the PC, right now I don’t need the extra space and I would lose having an external drive available anyway.

Does this means it is just not recommended to use them for backup?

I’ll have to look further into this, since it is my first time hearing about it and I’m not sure what it means. The SSD is a 2tb Crucial P3 Plus, nothing fancy. I’m now worried about the two 1tb 980 Pro I have from samsung currently running on my PC.